D2 4.6 conversion owners. 4.6 ECU swap & EOI.

[clubagreenie]

I have performed the swap that make the D2 what it should be but still have issues with pinging under load and also on bad/low octane (non 98 or 100) fuel.

I have spoke to a supplier who can ship 4.6 D2 ECU's for around $200- Aud landed. I'm planning on getting a couple to test and work out any issues with NAS spec vs Aust due to missing sensors etc and any effects.

Has anyone done this? If so what were the results and would anyone be interested in one once sorted out?

[jakeslouw]

So I assume Bosch Motronic?

Surely the Bosch is closed loop with knock sensors as well as the normal MAF stuff?

[clubagreenie]

It's got the knock sensors but watching the nanocom they don't really seem to cut in until 1800-2000rpm. Under load, such as accelerating from lights on a hill and such where you don't get to build revs unless I'm running BP 100 or Shell 98 it pings worryingly. On flats under load (such as towing) it's ok but I'd rather get it right. Have swapped out sensors to no avail. While it (and many other incl people in the US who have done the swaps) copes under the 4.0L management it is leaning out when you stick an analyser up the back. It runs both open and closed loop modes, depending on warm up status and MAF status (running constantly in one mode is a sure sign of a faulty MAF from experience.

For the price, there doesn't seem to be much to loose, and I can ship 2 for the same price as one so I thought someone else might want to "upgrade" as well. Either way I'll be reporting results of pinging, general running and most importantly economy.

[Pedro_The_Swift]

There are a few out there,, just the TRS customers alone--

might make a good tutorial or TGO post;):D

[jafir]

I have spoke to a supplier who can ship 4.6 D2 ECU's for around $200- Aud landed.

Looking in the catalog there are only two NAS ECU's, one for Secondary Air Injection and one without. So over here the same computer would go in a 4.0 or 4.6. I'm pretty sure the 4.6 is just set through a fuel map program.

I'm pretty sure something from black box solution could switch your ECU to the 4.6 mappings, assuming that land rover put it in there.... which there is a good chance that they did. On the old D1 here with the GEMS computers, the 4.6 program was an option, even though there were never any 4.6 liter Discovery Series 1.

[Pedro_The_Swift]

This post (at bottom) says test-book can change it--

d2 4.6 swap (http://www.lrrforums.com/showthread.php?20098-d2-4-6-swap)

you out there Blknight??

[banarcus]

But look where that forum is based, NAS where they had 4.0 and 4.6 D2s. There may be some merit exploring it, nothing to lose apart from a bit of cash for a test book looksee but from memory, reading RAVE on page 18-2-6 it says that the ECM holds both tunes but whether that is a NAS testbook setting or not needs to be explored.

[Pedro_The_Swift]

IIRC,, Blknight has one,, and Ron:eek:

[clubagreenie]

Ron as in out towards Penrith, approx 20 minutes away Ron?

[Pedro_The_Swift]

yep,,

[Mark Adams]

There are quite a few differences between the NAS (North American Specification) and ROW (Rest Of World) 4.0 and 4.6 Discoveries, and P38 Range Rovers.

I have studied them all in great detail for hundreds of hours in order to be able to reprogram them (which I have been doing successfully for over a year now), so the differences will be of interest. I don't want to be accused of promoting my business here, so I'm just going to stick to providing system information or responding to specific non-sales questions here.

The 4.6 Disco II was only sold in the NAS market, and it was fitted with the high-compression version of the engine. All of these vehicles had SAI (Secondary Air Injection) without exception. They were also fitted with a larger AFM (Air Flow Meter) akin to the P38, so they also had a different air filter housing and AFM to plenum trunk to accommodate the physical difference. Therefore putting a 4.6 ECU onto a 4.0 vehicle will not work properly, unless you use the larger AFM and associated parts also.

Using an SAI ECU in a non-SAI vehicle will cause it to put the CEL (Check Engine Lamp) on, although it doesn't always seem to cause them to go into limp-home mode.

There are three part numbers for the hardware versions of the the Disco Motronic ECU, but dozens of different tunes that are loaded into them. The ECU contains only one tune, specifically for the vehicle it was originally programmed for. It also contains the history, programming, and security information for that specific vehicle. Every ECU carries a label from the factory with the VIN number and software number that it was loaded with, unless it is a replacement part.

Note that it is not possible to implant a non-SAI tune into an SAI ECU or vice-versa, since there are enough hardware differences to stop it working. It runs, but really badly with lots of faults flagged. That is quite a pity, although I am continuing my studies to see if that can be overcome. Obviously it will never be possible to put an SAI tune into a non-SAI ECU (and who would want to?) since there are quite a few components not installed.

However it is quite straightforward to reprogram a 4.0 Litre non-SAI ECU with a 4.6 tune for the standard AFM, or even larger engines of the type we see over here (4.8 and 5.0 Litre are well known).

It seems that when BMW owned LR their marketing weasels deliberately nobbled the Disco against the P38 when tuning it, to prevent it being as quick. To that end they knocked a massive hole in the mid-range ignition timing, and it runs Lambda 1.0 across nearly the entire operating range. It does run open-loop at high load - it's just that the target is still Lambda 1.0 apart from the highest load and rev range. The P38 does feature a richer mixture under high load, but again the timing is not optimal.

These engines often pink or detonate because they have too lean a mixture, rather than just being an ignition timing issue. A colder grade of spark plug is good too.

[Pedro_The_Swift]

Thanks for that Mark,,

so the reprogramed ECU's that you sell have a better output than standard?, across the entire rev range?, using standard 4L inlet parts?

I dont suppose you can add both 4 and 4.6 tunes and make them switchable?

just for future expansion as it were---:angel:;)

[Mark Adams]

Wow! You're not called Pedro the Swift for nothing are you??? :D

The software only contains one very specific set of maps and configuration information at a time, so sadly it is not possible to have them switchable as with the older GEMS system which could contain up to four tunes.

Probably the biggest pain with the upgrade (apart from the price) is that I need to have the ECU here to modify it, which will stop a lot of people going for it. Once I have the ECU I can suck it's brains out, and then modify the tune. The vehicle tune information is then securely backed up here, meaning that in future I can produce exact clones where required, again with any modifications as required (e.g 4.0 to 4.6).

What many of my overseas clients choose to do is to fit another similar used ECU to their vehicle temporarily, and send the original over here. Once the upgraded original comes back to them, I can then clone a standard tune into their spare ECU so that they then have an interchangeable standard one.

[Mark Adams]

Sorry but I didnt' fully answer your question.


The Bosch engine is mapped in such a way that it produces maximum power when it hits the Rev Limiter, which is set at 5500 RPM. At this point the mixture is rather rich, but the ignition timing is fine for good power production.


Therefore the peak power will not improve more than 2-4 BHP with any upgrade, unless the Rev Limiter is moved up to say 6000 RPM. Although I could do this and the power is still increasing when it hits the Rev Limiter, it would be something of a “smoke and mirrors” or Snake Oil improvement. Power increases here are largely academic, since the vehicle will change gear long before this limit is reached.


However the dominant engine characteristic is actually a huge hole in the torque curve, centred around 2500 RPM. This is filled in very well with the upgrade, delivering an extra 10-15 lb/ft of torque and much faster throttle response. Economy improvement is 10-15%, although it is possible to angle the upgrade for ecnomy or power.


As we all know when driving a standard vehicle it actually pulls away from a standing start quite well initially, but loses interest once it gets to 3000 RPM. Personally I find this trait especially annoying, and it doesn’t even sound like a V8 either! All the action happens on the first or last quarter of the throttle pedal movement, and the bit in the middle doesn’t make a lot of difference. It is also a real nuisance to my clients who tow, since it often means the gearbox will kick down two gears when they only wanted a bit of extra effort (on a gradient for example).

Obviously the situation is different when putting a 4.6 engine under a 4.0 tune, which can still be disappointing since the lean mixture and retarded mid-range ignition is still a feature of the underlying programming.

[Pedro_The_Swift]

late edit; retyped after your last post

thats better,, and answers most of my edited questions:D

yep, midrange is the problem.

[jafir]

The 4.6 Disco II was only sold in the NAS market, and it was fitted with the high-compression version of the engine. All of these vehicles had SAI (Secondary Air Injection) without exception.

Actually there are some 03 and 04 Discovery (the only years with the 4.6L) over here that don't have SAI.... there are just so few that I've not seen any. There are a few guys on discoweb.org that work on them for a living, and even they have only seen one or two.

2004 Non-sai 4.6 Engine bay pics needed - DiscoWeb Message Boards (http://www.discoweb.org/forums/showthread.php't=80643&highlight=SAI)

[ozscott]

Im a bit lost here. I have a mate with an 03 D2a with a 4.6 RR motor with quite a bit of performance work and lumpier (not by a lot) cam than standard. Its running stock 4.0 intake runner, air box and MAF - and ECU. It goes hard without pinging. My stock 4.0 can ping at times even when warm and always running premium....MR did this work

TRS reckon the 4.6 they do will run stock ECU and MAF and no probs...so...is it a one off situation for pinging with the 4.6?

Cheers

[clubagreenie]

It definately runs, but it will ping under certain conditions and load and most importantly fuels.

I'm running std MAF I measured a few and couldn't find a difference

[Mark Adams]

Actually there are some 03 and 04 Discovery (the only years with the 4.6L) over here that don't have SAI


Thank you for that Jafir! I'm old enough to know better than to say "without exception" when talking about Land Rovers! :D

Of course I would love to see one of these vehicles, and even better get an ECU off one to have a look at. Do you know if these also have the larger AFM too?

[jafir]

Do you know if these also have the larger AFM too?

I think so. I've never seen anyone posting a complaint that it didn't work, but I've never seen one. I do know that over here the P38 range rover with motronics has this MAF, even with the 4.0, and I've put my larger 2003 4.6l discovery MAF and air intake hose on my 99 with a 4.0 for testing, and it seemed to work fine.

I've seen some catalogs mention the larger part number, MHK100800, for "gulf states" which I think means middle east. Maybe the figure that the larger sensor will flow more air for either a hotter climate, gulf states, or a possibly hotter engine compartment, 4.6L?

If I ever see a non-sai 4.6 in a salvage yard, I'll try to get the computer :)

[clubagreenie]

Mark, Speak to Justin @ Lucky 8 in New York. He's got both SAI & non SAI available.

[russV82a]

As far as I know, my 03 disco with a TRS 4.6 has the standard air box, MAF and intake setup and I have never heard it ping in the 2 years I've had the motor. I have never tried running it on 91 octane fuel however - I always use at least 95 octane - when running on petrol (it mainly runs on injected LPG). It is a the high compression motor with a custom TRS cam shaft grind.

It performs much better than the 4.0 - How it should have been from the factory!:)

[tempestv8]

I have seen the Secondary Air Injection plumbing on the DII in the USA.

My impression of SAI is that it's an emissions device only - when the engine is cold, the SAI pumps in extra air into the engine to speed up the warm up process. When the engine has reached normal operating temps, the SAI stops working and remains off.

I too have a 4.6 conversion on my DII, and I do agree with the sentiments that only the initial surge is there with the engine and when the revs climb, the output is rather meagre. Just lots of extra noise and not much urge.

I'd be interested to know if there has been any further developments.

[Mark Adams]

I have performed the swap that make the D2 what it should be but still have issues with pinging under load and also on bad/low octane (non 98 or 100) fuel.

Just thought you may like to know that I had a Range Rover P38 for diagnostics with nasty pinging (detonation) under load. This should never happen with the Bosch or GEMS systems unless something is wrong.

The vehicle in question turned out to have a defective air flow meter (AFM), which was under-reporting the actual load that the engine was running. At part load, the mapping will produce a great deal of ignition advance which drops away rapidly as the load goes up. Just to compound the problem it will be operating with a very lean mixture too, which is another cause of pinking.

This is actually quite a common failure mode for the Bosch AFM. Instead of just failing outright, they report a lower and lower load over time. Ultimately the vehicle has such a lean mixture and so much advance that it just bogs as you open the throttle, and will then record random misfires on random cylinders.

In this case, a new GENUINE Bosch AFM restored normal operation. Beware - there are loads of pattern copy Chinese cr*p versions out there.

I treat the AFM as a service consumable, and automatically fit a new one at around 80,000 Miles - especially for modified vehicles or those that have come in for tuning.

[clubagreenie]

I replaced the MAF about 20,000 ago just after doing the engine (and subsequently the auto which turned out to be the MAF clogged with oily water). Not 100% on it's source. Can you advise (PM) on dollars to send out one from a known source.

[clubagreenie]

What many of my overseas clients choose to do is to fit another similar used ECU to their vehicle temporarily, and send the original over here. Once the upgraded original comes back to them, I can then clone a standard tune into their spare ECU so that they then have an interchangeable standard one.

Mark,

How does a client here fitting a different ecu and sending the original to you for modding differ to sending a spare to mod while driving on the original? I know there's security issues but if it'll drive on a spare while you're working on the original then wouldn't it drive on the modded spare after you've worked on it?

[brougham]

So, is the MAF and and the AFM the same thing?

My 4.6L doesnt seem like it's any better than the standard 4.) as well, and it seems to struggle in the mid range as well. Always looking for ways to help it run better.

[clubagreenie]

MAF & AFM = same.

They tend to fail slowly and painfully.

[Signal1]

So I'm confused - not hard actually :angel:

I have recently acquired a D2 with near new 4.6 crate motor fitted. It would appear no other settings were touched as my mechanic said he had to tell it it had a 4.6 under the bonnet or something similar (I've come from 5 years of Td5 ownership, this is my first V8) as it was pinning. Whatever he did, its a little better.

So what do I have to do to get the most out of the 4.6?
a) replacement ECU from Mark
b) replace air intake components with those from a P38?
c) all above?

Thanks guys!
Peter

[walker]

Yes, I am in the same position as Pete. I have just bought a 99 d2 which had a 4.6 put in it about 30,000km ago. As far as I know only the bottom end was changed with High comp 4.6 block installed. I think all the top end remained 4.0. It also had sequential gas installed.

I would love to find out if I can improve output.

[clubagreenie]

Contrary to what has been mentioned, I've measured a few 4.6 P38 intakes and found them to be the same both in size and the actual metering component that is fitted to the tube with the two screws (you can buy it as a separate part from the tube suited to BMW's etc, same part) is also the same in both 4.0 & 4.6, at least physically and visually. I'm not keen on trying to adapt a whole new inlet to mine and I really don't think that the increase in capacity will out breathe whats there. It's possible that the meter is calibrated slightly differently, in which case you only need the correct part and fit it to your inlet tract.

But given that the same bosch part no for the meter itself (sans tubing) suits a variety of different manufacturers and engines & capacities I don't think the size matters (ladies will dispute) but the ecu does different things with the numbers when it all comes together.

[clubagreenie]

Going back to the bosch listings, the 03/04 D2 4.6 NAS spec has a different housing/meter assy number to the ROW 4.0 but the meter insert itself is the same. The P38 4.0 & 4.6 both have the same assy number & insert number which matches the D2 ROW 4.0 (all years). The earlier NAS spec (4.0) also has the same listing as the P38.

[Pedro_The_Swift]

I'd be willing to bet my 4.6 dollars on just replacing the ECU,,(and maybe a new MAF:angel:)

we probably need to confirm that a D2 will run on a second hand ECU.

anybody swapped out an ECU?

[clubagreenie]

Had a good talk to Mark last night (dont want to see the mobile bill). I'll be swapping out my original ECU for a 2nd hand one (anyone got a spare or know a source cheap?) Sending mine over for a reprogram and to trial in mine.

There's still a few things that prevent Mark from doing things on an exchange basis but I'll let him speak about those as they arise. Once I get it running, hopefully in about a month or two, depending on ECU availability, post and smash repairers, I'll have a working test drivable vehicle in Sydney.

Swapping the ECU for a spare is possible, just need a Nanocom etc to make the replacement learn the security from the BCU. But Mark needs the original for the reprogramming. It's possible for him to do it from one there and ship but it would take more effort on this end and there's a lot more potential for other issues that would cause bigger issues down the line than it's worth. So easiest option, find a spare ECU, install, learn and ship the known one for reprogramming.

Will keep this thread up to date as it comes along.

I also trialed a 4.6 non SAI ecu but it's an absolute failure, missing secondary O2 sensor inputs plus a lot of other stuff that's in the NAS spec vehicles. Tried a motec piggyback but cost is prohibitive as are other options by comparison. Marks units, apart from the initial setup are great value, can be duplicated into a back up ECU for tune changes after initial setup so changes could be managed with a straight swap and it's from someone who knows what the engines can & can't do, where the holes in the tune are and doesn't try to make it just make power.

[Signal1]

Appreciate this thread might run close indirectly pedaling Mark's business but are there certain packages you've been offered? Power, Power/Economy, Economy or just fix that mid-range flat spot ( :D ) for example?

Unfortunately their website (Tornado Systems) isn't informative.

Thanks,
Peter

[clubagreenie]

Mark's aimed more at just making it as all round good as it can be. As he says there's a flat spot in the tune and added to that the original tune is very lean, add extra capacity into it and it's even worse. Saying that there may be scope to move one way or the other, also depending on cams it may be possible. My primary aim is to get one working in mine and gather some more info for Mark.

Any change in the overall fuel delivery will make a few things better, even economy as if you don't need to floor it to make it move even if it's delivering more fuel it still must use less than taking off at full throttle all the time. FWIW put an auto into sport mode, find a nice flat straight road and accelerate. 5000rpm in each gear, 90 by the time it finds 3rd, keep going from there, trouble is the fuel gauge goes down at the same rate the tacho goes up.

[pieter]

Very interesting thread! Any update?

[Pedro_The_Swift]

you out there Clubba?

[jafir]

Going back to the bosch listings, the 03/04 D2 4.6 NAS spec has a different housing/meter assy number to the ROW 4.0 but the meter insert itself is the same. The P38 4.0 & 4.6 both have the same assy number & insert number which matches the D2 ROW 4.0 (all years). The earlier NAS spec (4.0) also has the same listing as the P38.

So maybe it is just the NAS p38 that has the bigger MAF housing? I wonder if Land Rover is just trying to confuse us. :)

So... NAS bosch p38 and NAS 03-04 D2 share a MAF?
And ROW p38a, NAS 99-02, and ROW D2 98-04 share a MAF?

[tempestv8]

I have sold my 4.6 Disco II but the new owner has done a test drive of the vehicle with the intake system not connected to the air cleaner box, i.e. the inlet tube and MAF were just breathing in fresh air from the engine bay.

Apparently the improvement to the driveability of the vehicle was noticeable.

So perhaps the aircleaner box and the Safari snorkel is quite restrictive.

[clubagreenie]

If I can get 800+hp from 4.7L running individual 52mm TB's an only introduce flow resitriction at 60mm then a snorkel is going to be fine. I can hear mine breathing through the snorkel from the top, the paper won't hold up unles covering more than a third of the snorkel head or more and even then a light breeze will disloge it.

Removal of the air cleaner make near enough to no difference n a vacuum gauge. Changing to a lett dense (and effective) filter does nothing except allow more dirt through.

[clubagreenie]

Also, in relation to the pinging issues, they have gone with the replacement of the MAF it would seem (or with the added replacement of the cam angle senor [CAS] which was originally intermittent but throwing it into the static 15deg retard timing. New MAF and 20,000km old known working CAS has made the timing variable, removed the pinging but made the fault persistent.

Pedro, will be calling Mark tonight, got a job for crazy vodka swilling (24/7) russian "business" man. So now I'm funded but time challenged. Culture shock from not working for 2.5 years to 9-5 2 Sats and one Sun/month. I told him to tell me what he'd pay then I aid how much I'd work. Plus weekends are cash cash.

So hopefully I can have a unit installed to demo drive, a spare test unit, a spare std unit (for exchange while reprogramming original unit) and perhap one day be able to do the reprog locally (at a better price and convenience than the other available that do not provide any useful info on what they do).

I'm alo chasing the fuel use issues, 350k's from the first tank after new CAS :eek:

[Mark Adams]

Please forgive the blatant sales plug, even though I'm a paid-up trader on this site. I thought you may enjoy a little clip of a Disco II I set up last year. It's well worth turning the volume up for this:

https://www.youtube.com/watch?v=UTtexZGLeIA

[Pedro_The_Swift]

yes, yes. next time I run the quarter I'll think of you Mark;)

How about you just sell me a box to help me tow my van around Australia??

[ozscott]

So to summarise....is it the case that a 4.6 converted thor d2 with original 4.0 intake, injectors, maf and ecu will run as hard as a north American 4.6 stocker? And is there any need to change ECU for a 4.6 hi comp?

Cheers

[Pedro_The_Swift]

I'm not at all sure there is an actual tuning difference between 4 and 4.6 ECM's,,

[Pedro_The_Swift]

Contrary to what has been mentioned, I've measured a few 4.6 P38 intakes and found them to be the same both in size and the actual metering component that is fitted to the tube with the two screws (you can buy it as a separate part from the tube suited to BMW's etc, same part) is also the same in both 4.0 & 4.6, at least physically and visually. I'm not keen on trying to adapt a whole new inlet to mine and I really don't think that the increase in capacity will out breathe whats there. It's possible that the meter is calibrated slightly differently, in which case you only need the correct part and fit it to your inlet tract.

But given that the same bosch part no for the meter itself (sans tubing) suits a variety of different manufacturers and engines & capacities I don't think the size matters (ladies will dispute) but the ecu does different things with the numbers when it all comes together.

The p38 maf is physically bigger,, but the p38 inlet tubing can not be made to fit a D2
IIRC,, the D2 runs 90mm and the p38 is 93?

[Mark Adams]

The 4.6 Litre version of the Discovery was only sold in North America, Canada, and Mexico. It was fitted with a larger Mass Air Flow (MAF) sensor, as used on all versions of the P38 Range Rover.

It is possible to fit this sensor to the 4.0 Litre vehicles at the same time they are reprogrammed with a Tornado upgrade, as the MAF characteristics are programmed in the software. It will not work properly otherwise.

Using a larger MAF will cause the system to see less air flow than the engine is actually consuming, so it will never add enough fuel. On top of this, there will probably be too much ignition advance at high loads for the same reason.

As yet I haven't had a chance to test the different MAF sensors back-to-back on the dyno, but my clients tell me it is worth around 10 BHP.

Since these are all parts from a standard vehicle, the correct air filter box lid and inlet trunk are available from the Land Rover parts catalogue. Alternatively they can be easily sourced from one of the many good USA vehicle breakers.

PHC000110 Air Filter Box Lid 4.6
PDH000480 Hose - MAF to Inlet Manifold 4.6

[Mark Adams]

So to summarise....is it the case that a 4.6 converted thor d2 with original 4.0 intake, injectors, maf and ecu will run as hard as a north American 4.6 stocker? And is there any need to change ECU for a 4.6 hi comp?

Cheers
Using a larger MAF will cause the system to see less air flow than the engine is actually consuming, so it will never add enough fuel. On top of this, there will probably be too much ignition advance at high loads for the same reason.

Motronic actually performs a very sophisticated measurement of the exact quantity of air the engine is consuming, which is the basis of all the fuelling and ignition calculations. In order to do this it needs to know the exact characteristics of the MAF meter, which are hard-programmed into the software.

Whilst the Motronic system will run a 4.6 engine even with a 4.0 Litre tune and standard MAF, you certainly won't be getting the best out of it. As your motor has Oxygen sensors in the exhaust, the fuelling runs in closed-loop which gives it the ability to trim the fuelling to suit the engine. Of course it will only be using the preset factory targets for this function. The ignition has knock detection to prevent detonation, which will also trim back any dangerous levels of ignition advance.

A couple of years ago when nobody could do anything with these systems, the stark choice with a capacity upgrade was to drop it in the hole and see what happened. As you can see from the last paragraph, Motronic will have a good shot at making the best of it. Indeed there are hundreds of these vehicles running around with 4.6 engines operating on 4.0 Litre tunes.

The fact that they work has lead to the general opinion that the conversion works, which is evidently true. However I will explain why you can get a very big improvement by reprogramming the ECM to suit the new larger engine.

As a bit of background, there are over 150 versions of the software for the Disco and it is important that you have the correct one. Earlier systems such as GEMS had software that would cope with pretty well any configuration of the vehicle, with just a few software switches. Although there are four types of Motronic ECM, the software is unique to each possible configuration of the vehicle.

The ECU mapping will need revision to accommodate the larger capacity, and here are the reasons why you would get a bad result from a 4.6 engine on a 4.0 map. The engine's fuel and ignition requirements are determined by engine speed and load. Engine load is determined by measuring the true mass of air that the engine is consuming at any particular speed, using the "Hot Film" Mass Air Flow (MAF) meter.

Mass airflow is proportional to the torque that the engine is producing (for this type of engine), and hence it is closely related to the engine capacity. This is also heavily influenced by atmospheric conditions such as barometric pressure, temperature, etc.

Therefore it is vital that the software is programmed with the correct maximum mass air consumption of the engine, known as airflow meter scaling. This is vital for good driveability and fuel economy especially on large capacity engines, and allows correct control of part throttle fuelling. Note that airflow meter scaling determines when the top of the fuel map is reached. When using an engine of larger capacity than the software was designed for, the top of the map will be reached too soon. This leads to over-fuelling at part throttle, and under-fuelling at full throttle.

A re-profiled Fuel Map which provides good fuel economy on part throttle, and allows engine to rev more freely (standard profile reduces fuelling heavily after 4000RPM). This produces quicker, more progressive throttle response and better mid range torque.

Although the ECU can work around large errors in the fuelling where Oxygen sensors are present where the map is significantly incorrect, when it reaches the limits of adjustment it will upset the entire fuelling learning process.

When re-calibrating the Motronic ECM for a larger capacity engine, there are actually over 38 maps that need re-scaling for both engine load and speed. This level of detail is one of the reasons why the Tornado upgrades are not cheap, although I do believe that the quality is unmatched.

[Pedro_The_Swift]

So,, after reading your first paragraph Mark,,
we DONT need to use a 4.6 MAF?

just confirming,,,:angel::D

and yes, I've moved again and still havent dug out the ECM numbers,,:angel:

[clubagreenie]

I don't think so. I've run similar capacities with smaller restrictors without issue. Audi are running their LMP diesels through about 36mm (by memory) restrictors and Peugeot LMP Gasolines through 33mm at far higher mass flow rates.

In mine it doesn't seem to be air thats an issue, though this para;


Therefore it is vital that the software is programmed with the correct maximum mass air consumption of the engine, known as airflow meter scaling. This is vital for good driveability and fuel economy especially on large capacity engines, and allows correct control of part throttle fuelling. Note that airflow meter scaling determines when the top of the fuel map is reached. When using an engine of larger capacity than the software was designed for, the top of the map will be reached too soon. This leads to over-fuelling at part throttle, and under-fuelling at full throttle.


correlates with gas analysis where idle hydrocarbons are off the chart and at 2500-3500 rpm cleaner than a D4. But with massive consumption rates.

[Mark Adams]

So,, after reading your first paragraph Mark,,
we DONT need to use a 4.6 MAF?

just confirming,,,:angel::D

and yes, I've moved again and still havent dug out the ECM numbers,,:angel:
Always wise to confirm!

You don't have to convert to the larger MAF with the 4.6 conversion, but you do need to re-program the ECM to get the best that the conversion has to offer.

Note that the larger engine does push the MAF towards the upper limit of it's measuring resolution.

If you would like to use the larger MAF, then it is worth power and metering accuracy. Again this needs to be taken into account when programming the Bosch ECM.

Therefore if you'd like the larger MAF, it's just good economics to do the whole lot at the same time. :)

I know you are a moving target at the moment! Hope you're having a great time! :cool:

[Pedro_The_Swift]

I've already have the 4.6 MAF :angel:,,
and the p38 inlet tubing:angel:
which is how I know it will never bolt up to a D2.

the easy way is to find tubing that will change diameter both before and after the 4.6 maf.

[Mark Adams]

I've already have the 4.6 MAF :angel:,,
and the p38 inlet tubing:angel:
which is how I know it will never bolt up to a D2.

the easy way is to find tubing that will change diameter both before and after the 4.6 maf.
Very helpful information Peter! As I haven't got a Disco on the test fleet it's not something I can check (we have a lovely P38 on which everything works - at least for the time being|).

The best way would probably be to get used parts from the USA. However I'll check the prices for the two parts required later today.

PHC000110 Air Filter Box Lid 4.6
PDH000480 Hose - MAF to Inlet Manifold 4.6

https://www.aulro.com/afvb/images/imported/2016/05/668.jpg (http://www.aulro.com/afvb/editpost.php'do=editpost&p=2320782)

[Pedro_The_Swift]

Mark,, the p38 inlet tubing doesnt have the "storage container" that the D2's have. There must be a reason LR designed it. :confused:

I gather you think the complete p38 airbox will bolt in to the D2?

[clubagreenie]

The "storage" container is there to eliminate harmonics at some order (1st, 2nd etc) caused by pulse reversion, usually when the accelerator is backed off and then pressed again. The fluid dynamics mean that the flow hits the closed butterfly and technical stuff happens and without the reserve the technical stuff can go awry.

Thats the short story. It's similar to why a plenum cover on a V engine is joined between the banks and also why it's tapered to be lower at the distal end of the inlets AND why the bellmouths are (very) slightly different heights and lengths. CFD of fluid flow in a plenum and what the air does as the valves close against flow is very cool.

http://www.intengineering.com/intblog/wp-content/uploads/2012/05/CYL4300.png

But it looks something like this, but more refined.

[jafir]

The best way would probably be to get used parts from the USA.

Do the air boxes and their lids in the UK and AUS have issues cracking?

It seems to be a pretty big problem here, and I'm not sure I'd buy another used one. My 2003 box was in pretty rough shape, and I bought a used one that looked fine. 6 months later, the clamps for the MAF were about to snap off due to cracks in the plastic. I'm not sure if it's climate or what. Personally, I'd buy a new lid, if the prices aren't too bad.

I don't know if they ship internationally, but this site lists the lid for 109USD. Land Rover Parts - Land Rover Parts Center - Call (800) 574-9217 for Genuine Land Rover Parts and Accessories (http://landrovermerriamparts.com/parts/index.cfm'searchText=PHC000110+&make=Land+Rover&action=oePartSearch&siteid=215719)
They are a main dealer in the Kansas City area, and I've purchased parts from them in the past.

It looks like the hose is just as pricey, but the only real issue I've seen with the hoses over time is that the port that goes to the IACV will sometimes come off, but it's pretty easy to remedy in most cases. On mine, I just sprayed it with silicone spray or something and pushed it through from the inside, and it was such tight fit, I'm sure it sealed just fine. I'd have no real issue ordering a used hose.

[Modelsp]

FWIW
i have the 4.6 maf in mine which is actually 23% larger internally
and the Mark Adams ECU it has the P38 filter box top on it now
and awesome Torque over the 4.0ltr and economy is yet to be confirmed as it has done all hard work from new.
See post in D2 V8's are great(9/2/15)
still need to get the gas retuned for the bigger motor as it seems to lean out then switch back to petrol
biggest problem so far is oil wicking down one of the sump bolts

[Pedro_The_Swift]

FWIW
i have the 4.6 maf in mine which is actually 23% larger internally
and the Mark Adams ECU it has the P38 filter box top on it now
and awesome Torque over the 4.0ltr and economy is yet to be confirmed as it has done all hard work from new.


So this confirms the P38 airbox LID just clips straight onto a D2 airbox???????

Modelsp?:angel::D

[Pedro_The_Swift]

Do the air boxes and their lids in the UK and AUS have issues cracking?



one lid lip on my airbox is cracked,, doesnt seem to leak though--

[Pedro_The_Swift]

still need to get the gas retuned for the bigger motor as it seems to lean out then switch back to petrol


is this with a sequential system Modelsp?
How can it lean out if the O2 sensors are working?
You out there Bee utey?;):D

[Modelsp]

Pedro
it runs/Idles ok on gas up to about2k revs then misses a bit and changes back to petrol
an ass>umption on my part about the lean bit,,thinking old school there.
i'll get it to the gas man when i finish wiring in the Harman Kardan amplifier and head unit all 956 wires of it.
Good old "She'll be right" should only take an hour or so>>>NOT!!

[bee utey]

Pedro
it runs/Idles ok on gas up to about2k revs then misses a bit and changes back to petrol
an assumption on my part about the lean bit,,thinking old school there.!
The sequential kits I've played with all rely on the pressure sensor for the vapour injection rail, they drop out when the pressure drops below a preset value. The leaning out/missing would be a result of the pressure drop. The LPG ECU wouldn't react to the lean mixture on its own.

Possible reasons for a pressure drop are

1. out of LPG

2. a helpful serviceman has shut off the main hand tap at the LPG tank, only not very tightly.

3. The excess flow valve at the LPG tank has tripped and needs a few goes on gas at idle to reset itself

4 . blocked filter in the main gas lock valve

5. dodgy (failed rubber seat in the) shut off plunger in the main gas lock

6. Converter internal blockage/damaged valve

7. Blocked inlet filter of the LPG tank shutoff valve

8. Broken pickup pipe at the LPG tank allowing only vapour into the system.

I would start by running the LPG for a short while, then stopping the engine and cracking open the line from the tank to the main gas lock. There should be plenty of liquid LPG present here, not just a short hiss of vapour.

[clubagreenie]

In addition to sizing of the inlet tract, consider the IACV (as I have been recently). It's orifice is about 20mm inlet and 15mm outlet. And it'll not only idle but with the TB inlet blocked but operating the butterfly it will breathe to over 2000rpm (without load) through the IACV hoses.

[Modelsp]

Sorry a bit late responding ,,but yes P38 lid fits straight on to the 4.6 maf sensor and original filter box.

[Pedro_The_Swift]

Sorry a bit late responding ,,but yes P38 lid fits straight on to the 4.6 maf sensor and original filter box.

Woo! Hoo!:TakeABow::clap2::banana:

[ozscott]

Great thread. Is there any difference in the size of the throttle body intake? If not what is the point of a higher volume plastic intake tube?

Cheers

[Modelsp]

Great thread. Is there any difference in the size of the throttle body intake? If not what is the point of a higher volume plastic intake tube?

Cheers

First of All Credit for the Airbox Lid information goes to Erich(Bundalene)as it was he who assisted me with this and a lid last week.
As for the Throttle body i'm unsure as the only advice from Mark Adams was to upgrade to the bigger MAF.=4.6ltr one.for the better fuel/air ratios
I think its not that relevant after the MAF as you can just open the throttle more if needed,(See >>>Drive it like you stole it).
cheers
Paul

[Pedro_The_Swift]

IIRC the throttle bodies are the same size,,
I'm sure LR had their reasons for the bigger inlet pipe:confused:

[jafir]

D2 and P38 (all V8 engine sizes) use the same part numbers for throttlebodies. There were different part numbers throughout the years, especially the early years, but they all supersede to the same number. MHB000240.

[Pedro_The_Swift]

Upgrade Update!
Second ECM coded by Millicent LR.
Job done in 30 minutes! :cool::cool: $70
Original ECM now in England,,
Airbox lid purchased from TRS, $70
P38 MAF already obtained.

Mark says the ECM should make it back here in time for Melrose!!

Melrose will be busy!!:D

[ozscott]

Cant wait for the drive report Pedro.

Cheers

[Pedro_The_Swift]

Freight Update!
ECM is in Botany!!
(via mainland USA and Honolulu:angel:)
due in Cockatoo Valley SA on Wednesday:cool::cool:

[clubagreenie]

Not if I get to "Botony" first

[Pedro_The_Swift]

well thats all gone to ****.
ECM is in a PO box in Cockatoo Valley SA.
We are at an Off Road Race in Vic,
and the owner of the PO box is off swanning around with the Ho Hars someplace else.
Looks like it will be posted to home.:(:mad::(

[clubagreenie]

Sure the box is "full"?

[Pedro_The_Swift]

no,, but as I seem to have lost the tracking number I can only ASSUME it made it.:confused:

[Pedro_The_Swift]

last ditch effort.
ECM to be posted to sisters at Dalby,, hopefully it will be there by thursday for the final tow leg to the Sunshine Coast.
cross your fingers everyone!:(

[Pedro_The_Swift]

Basil135 has kindly offered to pick the ECM up from Gawler and post it home to me.

[Pedro_The_Swift]

and home it is--:Thump:

[clubagreenie]

and home it is--:Thump:


This post is useless without results

[Pedro_The_Swift]

yea,,
but unless I get a before and after dyno sheet,,
"my" result will still be useless;)

"My bum tells me its faster!"


I suppose I could give Mrs Pedro a timing device and do a few "before and afters":confused:

[Pedro_The_Swift]

How do you dyno an auto??

[Eevo]

How do you dyno an auto??

same as a manual.
put it on the dyno, strap, apply right foot.

[Pedro_The_Swift]

:p
give you the bill?;)

[Pedro_The_Swift]

My bum tells me its faster----:angel:

[Pedro_The_Swift]

no, really!!!
it is.
quite a noticeable difference.

I still need to install the larger airbox lid and MAF,, but enlarging the pipe to 93 so it slips over the maf is tricky,,,

so there is still more to come,,:cool:

[clubagreenie]

I'm not convinced that it'll make a difference in airflow delivery. There may be an ECU effect where the MAF sensor "sees" a larger air mass delivery (bigger pipe) but the consumption of the engine (extra 75cc's per cyl) is hardly enough to need a change unless the previous was so marginal that they'd all improve with the increase.

[Pedro_The_Swift]

Mark thought it worth the effort,,:confused:
just have to think up a way to do it,,

[Modelsp]

Pedro
I used a heat gun/hair dryer to warm/heat mine up and stretched it over a piece of water downpipe that bring it up to size nicely.
the down pipe can be tapered in the same manner to make it tapered beforehand.
I did mine over the small gas burner on the Kitchen stove gently rotating it until it became flexible you can then form it by hand with a garden glove on.
once tapered you then do the same with the hair dryer for the MAF tube over the downpipe.
cheers
Paul

[Pedro_The_Swift]

was fun last night on our pizza run,,
roads all wet 'n everything--
:angel::twisted::angel:

[banarcus]

So do we have any results? I am keen to see what the difference is.

[Pedro_The_Swift]

results?
do you mean actual numbers?

[Fluids]

... apparently, some say, it can now (just) outrun a std Td5 ...

... but it's all hearsay until we see some numbers :p

[ozscott]

Haha...I like it. Of course you can only sell that to people who havent driven a TD5 or two...

Cheers

[ozscott]

I know a sequential injected LPG system bases its injection off the fuel injection but will the lpg tune better for a 4.6 than the petrol i jection will?

Otherwise if not does running LPG with a high comp 4.6 work better than petrol - ie all with stock 4.0 ecu and intake etc?

Cheers

[bee utey]

LPG will follow the petrol map during closed loop operation as the fuelling is tied to oxygen sensor readings. At WOT (open loop) you can set the LPG map to suit yourself, software permitting.

[ozscott]

Thanks mate. That might cure any lean state at large throttle inputs that Mark Adams was speaking of...although if the lean state is also there with large but not wot throttle positions that might not help with towing heavy loads. I can only hope the extra torque of both the 4.6 stroke and the extra torque of LPG means less throttle inputs are required anyway.

Cheers

[Pedro_The_Swift]

The 4.6 ECU does not run lean---:p
The tailpipe was always a clean steel colour with the 4L
its now black

and you can judge yourself by my internal pics how the 4L tune runs,,,,,

[ozscott]

Hi mate. I understood Mark to say that a 4.6 litre running a 4 litre ECU runs too lean at wide open throttle and too rich at part throttle. Cheers

[Pedro_The_Swift]

Its certainly a different car with his 4.6 ECM:eek::cool:

[ozscott]

Pedro have you considered a different air intake alltogether....say a sealed cylindrical intake and filter with large diameter inlet and outlet. I understand you can buy thick rubber tubes these days in whatever size for running to MAF. A BMW V8 airbox or outlet pipe from the same year as the d2 should run the same MAF.

Is the bigger MAF just the insert or is the whole housing bigger? So the 4.6 d2 n the US runs larger air intake and then same size throttle body as d2 4.0? Ie hose reduces in size at throttle body.....i am having trouble visualising the set up...

Cheers

[ozscott]

Edit...i read elsewhere that the throttle body is larger also in NAS 4.6 D2...

Cheers

[Pedro_The_Swift]

Its bigger from the airbox outlet through the MAF, then its back to the smaller tubing into the throttle body, my ECM is expecting different numbers due to the higher( but slower?) volume of air.

can someone check the part numbers on microcat?

[ozscott]

Thanks mate. So its an odd shaped MAF. Presumably its the same part as say a 99 4.6 p38A RR?

Cheers

[ozscott]

There are quite a few differences between the NAS (North American Specification) and ROW (Rest Of World) 4.0 and 4.6 Discoveries, and P38 Range Rovers. <br />
<br />
I have studied them all in great detail for hundreds of hours in order to be able to reprogram them (which I have been doing successfully for over a year now), so the differences will be of interest. I don't want to be accused of promoting my business here, so I'm just going to stick to providing system information or responding to specific non-sales questions here.<br />
<br />
The 4.6 Disco II was only sold in the NAS market, and it was fitted with the high-compression version of the engine. All of these vehicles had SAI (Secondary Air Injection) without exception. They were also fitted with a larger AFM (Air Flow Meter) akin to the P38, so they also had a different air filter housing and AFM to plenum trunk to accommodate the physical difference. Therefore putting a 4.6 ECU onto a 4.0 vehicle will not work properly, unless you use the larger AFM and associated parts also.<br />
<br />
Using an SAI ECU in a non-SAI vehicle will cause it to put the CEL (Check Engine Lamp) on, although it doesn't always seem to cause them to go into limp-home mode.<br />
<br />
There are three part numbers for the hardware versions of the the Disco Motronic ECU, but dozens of different tunes that are loaded into them. The ECU contains only one tune, specifically for the vehicle it was originally programmed for. It also contains the history, programming, and security information for that specific vehicle. Every ECU carries a label from the factory with the VIN number and software number that it was loaded with, unless it is a replacement part.<br />
<br />
Note that it is not possible to implant a non-SAI tune into an SAI ECU or vice-versa, since there are enough hardware differences to stop it working. It runs, but really badly with lots of faults flagged. That is quite a pity, although I am continuing my studies to see if that can be overcome. Obviously it will never be possible to put an SAI tune into a non-SAI ECU (and who would want to?) since there are quite a few components not installed.<br />
<br />
However it is quite straightforward to reprogram a 4.0 Litre non-SAI ECU with a 4.6 tune for the standard AFM, or even larger engines of the type we see over here (4.8 and 5.0 Litre are well known).<br />
<br />
It seems that when BMW owned LR their marketing weasels deliberately nobbled the Disco against the P38 when tuning it, to prevent it being as quick. To that end they knocked a massive hole in the mid-range ignition timing, and it runs Lambda 1.0 across nearly the entire operating range. It does run open-loop at high load - it's just that the target is still Lambda 1.0 apart from the highest load and rev range. The P38 does feature a richer mixture under high load, but again the timing is not optimal.<br />
<br />
These engines often pink or detonate because they have too lean a mixture, rather than just being an ignition timing issue. A colder grade of spark plug is good too.

Mark seems to be saying that the tube from the MAF to plenum (throttle body he means) is larger too. That would make sense...both sides of MAF chamber same size as each other then slowly shrinking tube to throttle body. Cheers

[ozscott]

Part nos for MAFs based on a search

ERR7171 for 4.0 dimensions:*0.14 m x 0.17 m x 0.11 m -weight:*0.311 kilo


MHK100800 for 4.6 D2 (and RR 95-02) *0.13 m x 0.14 m x 0.13 m - Weight:*0.294 kilo


Cheers

[Pedro_The_Swift]

Thanks mate. So its an odd shaped MAF. Presumably its the same part as say a 99 4.6 p38A RR?

Cheers

if thats the Thor engine then yes.

and the reason I want to keep the original inlet maf to plenum tubing, it has special sonic boom chambers,, these soak up the air shock waves of a shut off throttle,
apparently--:angel:

[Pedro_The_Swift]

its just a motivation problem;)

I keep having visions of metal funnels and rubber grease:wasntme:

[ozscott]

I cannot find the maf to plenum duct part number for a 4.6. That might be the sticking point. I suppose also the more we move away from stock the more its hard to get parts quickly if needed....for the intake duct for example.


Cheers

[jafir]

Thank you for that Jafir! I'm old enough to know better than to say "without exception" when talking about Land Rovers! :D

Of course I would love to see one of these vehicles, and even better get an ECU off one to have a look at. Do you know if these also have the larger AFM too?

So I snagged one of these ECUs today. I was surprised because the part number on it would have led me to believe that the engine WAS LEV/SAI, but based on all of the emissions stickers it is not SAI, and the engine didn't have it, and the vacuum diagram didn't show it.

Feel free to contact me if you still have any interest in getting your hands on it. If not, I'll just keep it for my own potential use.

[Pedro_The_Swift]

a 3 year search!:clap2:
so this is off a factory 4.6
without secondary air injection?

wow. big score.:Thump:

[jafir]

Yep. I was standing in a Land Rover garage, and one of the guys needed a piece of the plumbing for the SAI and he joked that the first 03 in the parts lot the he picked was one of the few that didn't have SAI. And I said, "Wait.... you've got a 4.6 without SAI? Can I buy the computer?" :)

I can say I wasn't looking TOO hard... because I've been to this shop a few times and I didn't even think to ask the last couple of times.

Without:
101175

With:
101176

[Battler]

I've just read this in Rave:

A single ECM is used for the control of the existing 4.0 litre engine and the new 4.6 litre engine introduced with 03 model year vehicles for the NAS market only. The ECM contains the tunes for both engines variants. When the ECM is replaced, TestBook/T4 must be used to select the correct tune to match the engine fitment.

So, would this mean if you got a ECU from a 03 onwards it would be switchable between the 4.0l and 4.6l?

Anybody done this?

Cheers

[Pedro_The_Swift]

sort of,,
go back one post.
99% of all the NAS (north american spec) D2's used SAI,, secondary air injection.
Thats why jafir's find was a biggie.
no SAI in that ECM.

AFAIK all the D2 ECM's for the rest of the world only had one tune,,
and a sad hollow sound it is,,:mad:

[jafir]

I've just read this in Rave:

A single ECM is used for the control of the existing 4.0 litre engine and the new 4.6 litre engine introduced with 03 model year vehicles for the NAS market only. The ECM contains the tunes for both engines variants. When the ECM is replaced, TestBook/T4 must be used to select the correct tune to match the engine fitment.

So, would this mean if you got a ECU from a 03 onwards it would be switchable between the 4.0l and 4.6l?

Anybody done this?

Cheers

Sometimes RAVE contradicts itself. I believe this is the way the earlier GEMS computers worked, but not that Bosch computers. Later in the same section of the manual, it says that you have to reflash the eeprom to change tunes:

"The ECM can be reprogrammed, using TestBook/T4, with new engine tunes up to 16 times to meet changing specifications and legislation. The current engine tune data can be accessed and read using TestBook/T4."

Normally the testbook will flash the computer based on the VIN number. Here is some info from BBSGuy, that seems to indicate that settings cannot be edited in the ECU, and only a complete reflash, but I might be reading more into his words than is really there: http://www.aulro.com/afvb/electronic-diagnostic-systems/172574-vin-motronic-v8-d2-using-nanocom.html#post1893489

[Battler]

What about MegaSuirt? 735 UK pounds for a complete Thor kit.

Has anybody done this or thinking about?

Cheers

[Modelsp]

I wonder if VW Chips would work
They'd be Awesome.
Mine runs fine with the Mark Adams in it
although a little rich down low
might see if the 4.6 O2 sensors are the same as 4.0ltr

[Pedro_The_Swift]

This care of Modelsp;)

"Hello

Thank you for your message - it's good to hear from you. Although this is a simple question at first glance, it does deserve a detailed answer. I hope I am not swamping you with information!

Whilst the Motronic system will run a 4.6 engine even with a 4.0 Litre tune, you certainly won’t be getting the best out of it. As your motor has Oxygen sensors in the exhaust, the fuelling runs in closed-loop which gives it the ability to trim the fuelling to suit the engine. Of course it will only be using the preset factory targets for this function. The ignition has knock detection to prevent detonation, which will also trim back any dangerous levels of ignition advance.

A couple of years ago when nobody could do anything with these systems, the stark choice with a capacity upgrade was to drop it in the hole and see what happened. As you can see from the last paragraph, Motronic will have a good shot at making the best of it. Indeed there are hundreds of these vehicles running around with 4.6 engines operating on 4.0 Litre tunes.

The fact that they work has lead to the general opinion that the conversion works, which is evidently true. However I will explain why you can get a very big improvement by reprogramming the ECM to suit the new larger engine.

As a bit of background, there are over 150 versions of the software for the Disco and it is important that you have the correct one. Earlier systems such as GEMS had software that would cope with pretty well any configuration of the vehicle, with just a few software switches. Although there are four types of Motronic ECM, the software is unique to each possible configuration of the vehicle.

There are some solutions for this one, although none of them are ideal. Sending the original ECM puts you off the road for several days at least, even if using a courier such as DHL. As you say, for a daily driver this is a no-go.

A couple of my clients have sourced a similar ECM locally, and used that whilst they sent their own over here. As mentioned above, it does need to be the same version. The chassis number and software version are always printed on the casing at the factory, but the label is made of paper and often peels off. It is theoretically possible to obtain the correct ECM, and load it with software over here and send it out. However you would lose the programming history of the vehicle this way. I am working on a way around this, but haven’t got there yet due to the encryption involved.

In all cases when using the non-original ECM, it is necessary to use specialist test equipment to re-learn the security code for a Discovery. This is an added pain and expense unless you already own such equipment.

Anyway - that is all the negative stuff. There are considerable benefits to be had if you can take the hassle.

The ECU mapping will need revision to accommodate the larger capacity, and here are the reasons why you would get a bad result from a 4.6 engine on a 4.0 map. The engine's fuel and ignition requirements are determined by engine speed and load. Engine load is determined by measuring the true mass of air that the engine is consuming at any particular speed, using the "Hot Film" Mass Air Flow (MAF) meter.

Mass airflow is proportional to the torque that the engine is producing (for this type of engine), and hence it is closely related to the engine capacity. This is also heavily influenced by atmospheric conditions such as barometric pressure, temperature, etc.

Therefore it is vital that the software is programmed with the correct maximum mass air consumption of the engine, known as airflow meter scaling. This is vital for good driveability and fuel economy especially on large capacity engines, and allows correct control of part throttle fuelling. Note that airflow meter scaling determines when the top of the fuel map is reached. When using an engine of larger capacity than the software was designed for, the top of the map will be reached too soon. This leads to over-fuelling at part throttle, and under-fuelling at full throttle.

A re-profiled Fuel Map which provides good fuel economy on part throttle, and allows engine to rev more freely (standard profile reduces fuelling heavily after 4000RPM). This produces quicker, more progressive throttle response and better mid range torque.

Although the ECU can work around large errors in the fuelling where Oxygen sensors are present where the map is significantly incorrect, when it reaches the limits of adjustment it will upset the entire fuelling learning process.

When re-calibrating the Motronic ECM for a larger capacity engine, there are actually over 38 maps that need re-scaling for both engine load and speed. This level of detail is one of the reasons why the Tornado upgrades are not cheap, although I do believe that the quality is unmatched.

The following information refers to either upgrading a 4.0 or 4.6 vehicle in the same capacity, but the gains are much larger when going from a 4.0 to 4.6. If you want the technical details of why this is so then I would be very happy to provide them.

The Bosch engine is mapped in such a way that it produces maximum power when it hits the Rev Limiter, which is set at 5500 RPM. At this point the mixture is rather rich, but the ignition timing is fine for good power production. Therefore the peak power will not improve more than 2-4 BHP with any upgrade, unless the Rev Limiter is moved up to say 6000 RPM. Although I can do this and the power is still increasing when it hits the Rev Limiter, it would be something of a “smoke and mirrors” or Snake Oil improvement. Power increases here are largely academic, since the vehicle will change gear long before this limit is reached.

However the dominant engine characteristic is actually a huge hole in the torque curve, centred around 2500 RPM. This is filled in very well with the upgrade, delivering an extra 10-15 lb/ft of torque and much faster throttle response. Economy improvement is 10-15%.

When driving a standard vehicle it actually pulls away from a standing start quite well initially, but loses interest once it gets to 3000 RPM. Personally I find this trait especially annoying, and it doesn’t even sound like a V8 either! All the action happens on the first or last quarter of the throttle pedal movement, and the bit in the middle doesn’t make a lot of difference. It is also a real nuisance to my clients who tow, since it often means the gearbox will kick down two gears when they only wanted a bit of extra effort (on a gradient for example).

Once I have extracted the software from your ECU, I can clone it in future if you should ever lose or damage your original. However, if it gets lost on the way up then it would be necessary to have a new one installed and programmed using TestBook or RovaCom – expensive hassle you don’t need!

Although I can happily send you the graphs for a 4.6 Range Rover or 4.0 Discovery (since we don’t have the 4.6 Discovery over here), they aren’t very helpful due to the fact that the vehicle is automatic and we have to test it in third gear. This brings the attendant problems of kick-down in the middle of the run (right where the best gains are), and the graphs are a bit of a mess. Whilst vehicles with manual transmission do exist which would give the most meaningful results, I have yet to see one."

[ozscott]

Im sure he would like to see a manual. Mine does not drive like it has a hole in the power band at beywee between 2500 and 3000 plus rpm....in fact it goes hard to injector cut off. I will try to post a video. The fuel economy non highway that i have posted elsewhere speaks for itself. I might have just got lucky. I once used a K&N filter in my 4.0. Not long later i went to paper again on seeing filtration tests. My bet is that Marks upgrade is like fitting a K&N...better throttle respose and a crisper feeling.

Cheers

[Pedro_The_Swift]

and if I fit a K&N to mine,, ?
:p:D

[ozscott]

Would give it more again for sure mate. I just didnt trust the filtration. Cheers

[Mark Adams]

Sometimes RAVE contradicts itself. I believe this is the way the earlier GEMS computers worked, but not that Bosch computers. Later in the same section of the manual, it says that you have to reflash the eeprom to change tunes:

"The ECM can be reprogrammed, using TestBook/T4, with new engine tunes up to 16 times to meet changing specifications and legislation. The current engine tune data can be accessed and read using TestBook/T4."

Normally the testbook will flash the computer based on the VIN number. Here is some info from BBSGuy, that seems to indicate that settings cannot be edited in the ECU, and only a complete reflash, but I might be reading more into his words than is really there: http://www.aulro.com/afvb/electronic-diagnostic-systems/172574-vin-motronic-v8-d2-using-nanocom.html#post1893489

You're absolutely right Jafir. GEMS did work that way, although there was a booby trap. Although you could actually switch between 4.0 and 4.6, manual and auto software, sometimes the chips only actually had one tune in them (notably the the 4.0 auto Defender). Therefore whatever it was set to, you still got a 4.0 auto (for example).

With Motronic, the settings cannot be edited or switched without a re-flash. The basic ECM can be loaded with any one of a number of different software versions, but is constructed of many components to suit the build of the vehicle.

We know there are four different Bosch ECM part numbers for these vehicles, but we have found over 150 versions of the software so far! In all cases, the software is specific to the ECM hardware it is intended for. I have tried running alien versions of the software and although they run, they don't run well. The hardware is just different enough to stop it working properly.

[Mark Adams]

Edit...i read elsewhere that the throttle body is larger also in NAS 4.6 D2...

Cheers
All Thor motors have the same size throttle body on them. Although there are a couple of different part numbers, the changes were actually to do with the water heating jacket underneath it which was prone to leaking in early models.

[Mark Adams]

Thanks mate. So its an odd shaped MAF. Presumably its the same part as say a 99 4.6 p38A RR?

Cheers
You are right - it is the same as a P38 RR. I have put a picture of the P38 and Disco MAF next to each other on our Facebook page here:

https://www.facebook.com/tornadosystems

Here's the words for those who don't want to look at Facebook: :D

This picture is for Land Rover Discovery II owners, equipped with the Bosch Motronic-managed Thor engine. It shows the difference between the standard Mass Air Flow (MAF) sensor used with all 4.0 Litre versions of the Disco II, and the larger version used on the P38 Range Rover and 4.6 Litre Disco II sold in North America.



The P38 has an internal diameter of 76.5mm, whilst the Disco II is 70mm. This doesn't sound like a huge difference, but the available area is proportional to the square of the radius, less the area obstructed by the measuring bridge (which is the same for both meters). The difference is nearly an 19.5% extra area!


As yet, we haven't managed to get a Disco II on the rollers for a back-to-back comparison. Anecdotally from our clients, it appears to offer a gain of around 10 BHP which is especially apparent after 3000 RPM. This is clearly going to be different for 4.0 Litre and 4.6 Litre engines, but it appears to be a worthwhile modification to do at the same time as reprogramming the ECM with a Tornado upgrade.

[ozscott]

Mark you are a champion. So i understand can i get a p38A air box lid and a 4 6 P38a thor motor MAF and the lid will connect up to the 4.0 D2 air box base and the 4.6 MAF will connect and fit to the 4.0 plastic intake tube that runs up to the throttle body?

How would such a mod go without the Tornado upgrade....i know Tornado would be the ultimate but any downside in the meantime to me doing the 4.6. maf?

Cheers

[Pedro_The_Swift]

The 4L thor inlet ducting is the size to go over the 4L maf
it has to be managed/massaged to fit onto the larger 4.6 maf

this from last year,
http://www.aulro.com/afvb/showthread.php?p=2456319#post2456319

The RR Thor inlet is the total wrong shape(but right size) to suit the D2
The P38Airbox lid fits and is the right outlet shape to suit the 4L tubing.

any help?

[ozscott]

Thanks Pedro. Does the massaging (stretching) cause splitting in the long run or are we talking just a little bit tighter. Have you run the bigger MAF?

Cheers

[Pedro_The_Swift]

Its been done,,
just not by me yet.(sorry Mark!;))

apparently you just get it warm/hot and stretch it over the maf:confused:

[Battler]

Would changing to the larger MAF make any difference if the throttle body and the inlet tube remains the same size?

[Eevo]

depends if the MAF was a bottleneck or not

[Pedro_The_Swift]

Would changing to the larger MAF make any difference if the throttle body and the inlet tube remains the same size?

A question for Mark perhaps,,

all I know is my ECM has been setup/calibrated/coded for the larger maf,, it expects X amount of airflow and is only getting X-minus 19%.

I would imagine X-plus 19% if you just add the bigger maf without the coded ECM....

[Battler]

I'm no expert but I think the MAF measures the air coming into the engine so it can adjust fuel mixture accordingley. So I would have thought, unless you increase the diameter of the parts pre and post MAF there would be no difference in the amount of air passing through the MAF.

I hope I'm wrong as I have a 4.6 and I would love to get more air into the engine. Then there's the problem of the inlet manifold.

I know JE Engineering in the UK did something with the throttle body and inlet manifold to get more power. But not sure of the outcome. I'll see if I can find something on it.

[Pedro_The_Swift]

If that was the case,, LR wouldnt have made the 4.6 maf bigger,,
need inlet options?
http://www.mez.co.uk/ms12-new.html

yea, lots of cool inlet manifolds/throttle bodies,, none give you the low down torque of the original.
this is nice
https://www.aulro.com/afvb/images/imported/2015/11/133.jpgneed

[Battler]

Yeah I guess there must be some reason for the larger MAF.

Those inlet manifolds are nuts. You would have to fully work the heads to get the full benefit of them. Money and more money for HP. Would be cheaper to put in a 5.7l LS1.

[Mark Adams]

Mark you are a champion. So i understand can i get a p38A air box lid and a 4 6 P38a thor motor MAF and the lid will connect up to the 4.0 D2 air box base and the 4.6 MAF will connect and fit to the 4.0 plastic intake tube that runs up to the throttle body?

How would such a mod go without the Tornado upgrade....i know Tornado would be the ultimate but any downside in the meantime to me doing the 4.6. maf?

Cheers

Normally I like to quote from experience, backed up with the science. The Disco II market is an unusual one for me, in that most of my clients are overseas dotted around the world.

Several of my clients have reported that the Throttle to MAF hose will fit on the larger P38 MAF, simply by dunking the end in some hot water first. When you measure the outside diameter (OD) of the stock D2 MAF where the hose goes on it is 80mm, and the P38 one is actually only 83mm!

The difference is that the side wall thickness of the D2 MAF is much greater; surprisingly so in fact! However it does mean that only a small stretch is required to make the trunk stretch onto the P38 MAF.

[Mark Adams]

Would changing to the larger MAF make any difference if the throttle body and the inlet tube remains the same size?
That's a very valid question. As it turns out, the D2 MAF is quite a lot smaller than the cross-sectional area of the tubing it is connected to. Using a P38 just makes more of this available (19.5% increase), so in essence it reduces an already-present restriction.

[Mark Adams]

Would changing to the larger MAF make any difference if the throttle body and the inlet tube remains the same size?
That's a very valid question. As it turns out, the D2 MAF is quite a lot smaller than the cross-sectional area of the tubing it is connected to. Using a P38 just makes more of this available (19.5% increase), so in essence it reduces an already-present restriction.

[Mark Adams]

Yeah I guess there must be some reason for the larger MAF.

Those inlet manifolds are nuts. You would have to fully work the heads to get the full benefit of them. Money and more money for HP. Would be cheaper to put in a 5.7l LS1.
The big challenge with changing engines in these is very rarely the cost of the engine. Unless you have a manual transmission and no other equipment on the vehicle, there are major issues with interfacing to these other systems.

Also you then have a vehicle that cannot necessarily be fixed from the Land Rover parts bin, which despite its faults is readily accessible in most corners of the globe.

I've done quite a few transplants myself (and indeed have a 4.8 Litre Ford Sierra with a GEMS-managed engine in), and I know that the engine is usually less than half the cost of the job.

[Mark Adams]

A question for Mark perhaps,,

all I know is my ECM has been setup/calibrated/coded for the larger maf,, it expects X amount of airflow and is only getting X-minus 19%.

I would imagine X-plus 19% if you just add the bigger maf without the coded ECM....
Sorry about this giant post, but there's quite a lot to this one!

Using a larger MAF will cause the system to see less air flow than the engine is actually consuming, so it will never add enough fuel. On top of this, there will probably be too much ignition advance at high loads for the same reason. This is why it is a great time to incorporate this modification, as all these things can be accounted for in one go

Motronic actually performs a very sophisticated measurement of the exact quantity of air the engine is consuming, which is the basis of all the fuelling and ignition calculations. In order to do this it needs to know the exact characteristics of the MAF meter, which are hard-programmed into the software.

Whilst the Motronic system will run a 4.6 engine even with a 4.0 Litre tune and standard MAF, you certainly won't be getting the best out of it. As your motor has Oxygen sensors in the exhaust, the fuelling runs in closed-loop which gives it the ability to trim the fuelling to suit the engine. Of course it will only be using the preset factory targets for this function. The ignition has knock detection to prevent detonation, which will also trim back any dangerous levels of ignition advance.

A few years ago when nobody could do anything with these systems, the stark choice with a capacity upgrade was to drop it in the hole and see what happened. As you can see from the last paragraph, Motronic will have a good shot at making the best of it. Indeed there are hundreds of these vehicles running around with 4.6 engines operating on 4.0 Litre tunes.

The fact that they work has lead to the general opinion that the conversion works, which is evidently true. However I will explain why you can get a very big improvement by reprogramming the ECM to suit the new larger engine.

As a bit of background, there are over 150 versions of the software for the Disco and it is important that you have the correct one. Earlier systems such as GEMS had software that would cope with pretty well any configuration of the vehicle, with just a few software switches. Although there are four types of Motronic ECM, the software is unique to each possible configuration of the vehicle.

The ECU mapping will need revision to accommodate the larger capacity, and here are the reasons why you would get a bad result from a 4.6 engine on a 4.0 map. The engine's fuel and ignition requirements are determined by engine speed and load. Engine load is determined by measuring the true mass of air that the engine is consuming at any particular speed, using the "Hot Film" Mass Air Flow (MAF) meter.
Mass airflow is proportional to the torque that the engine is producing (for this type of engine), and hence it is closely related to the engine capacity. This is also heavily influenced by atmospheric conditions such as barometric pressure, temperature, etc.

Therefore it is vital that the software is programmed with the correct maximum mass air consumption of the engine, known as airflow meter scaling. This is vital for good driveability and fuel economy especially on large capacity engines, and allows correct control of part throttle fuelling. Note that airflow meter scaling determines when the top of the fuel map is reached. When using an engine of larger capacity than the software was designed for, the top of the map will be reached too soon. This leads to over-fuelling at part throttle, and under-fuelling at full throttle.

A re-profiled Fuel Map which provides good fuel economy on part throttle, and allows engine to rev more freely (standard profile reduces fuelling heavily after 4000RPM). This produces quicker, more progressive throttle response and better mid range torque.

Although the ECU can work around large errors in the fuelling where Oxygen sensors are present where the map is significantly incorrect, when it reaches the limits of adjustment it will upset the entire fuelling learning process.

When re-calibrating the Motronic ECM for a larger capacity engine, there are actually over 38 maps that need re-scaling for both engine load and speed. This level of detail is one of the reasons why the Tornado upgrades are not cheap, although I do believe that the quality is unmatched.

[Mark Adams]

Yeah I guess there must be some reason for the larger MAF.

Those inlet manifolds are nuts. You would have to fully work the heads to get the full benefit of them. Money and more money for HP. Would be cheaper to put in a 5.7l LS1.

Or this...

https://youtu.be/UTtexZGLeIA

[Pedro_The_Swift]

sigh,
just ruined my entire day Mark:(:p

[Battler]

That's a very valid question. As it turns out, the D2 MAF is quite a lot smaller than the cross-sectional area of the tubing it is connected to. Using a P38 just makes more of this available (19.5% increase), so in essence it reduces an already-present restriction.

So could then modify the existing MAF to match the tube it's connected to and use the same sensor?

[Battler]

The big challenge with changing engines in these is very rarely the cost of the engine. Unless you have a manual transmission and no other equipment on the vehicle, there are major issues with interfacing to these other systems.

Also you then have a vehicle that cannot necessarily be fixed from the Land Rover parts bin, which despite its faults is readily accessible in most corners of the globe.

I've done quite a few transplants myself (and indeed have a 4.8 Litre Ford Sierra with a GEMS-managed engine in), and I know that the engine is usually less than half the cost of the job.

I agree; tongue in cheek there Mark. I know my 4.6 has far more potential.

When I had the engine in my bobbed RR comp safari with a Jag flapper style MAF and a 14CUX expertly tuned by you it went like a rocket. Admittedly there's is a fair bit of weight difference between that car and the D2 but it's lost a lot of power. it just doesn't rev like it use to.

[Battler]

Or this...

https://youtu.be/UTtexZGLeIA

Is that a modified Thor inlet manifold by ACT?

[Mark Adams]

Is that a modified Thor inlet manifold by ACT?
The manifold was replaced with an earlier GEMS version, allowing the plenum to bolt straight on. RPI did the work, and they used to have the photos on their Facebook page. You'll have to go a long way down to see them, as it was about April last year (2014) when it was done.

If there was enough demand, I'm sure ACT could do a plenum base to allow continued use of the inlet manifold you already have.

[Mark Adams]

I agree; tongue in cheek there Mark. I know my 4.6 has far more potential.

When I had the engine in my bobbed RR comp safari with a Jag flapper style MAF and a 14CUX expertly tuned by you it went like a rocket. Admittedly there's is a fair bit of weight difference between that car and the D2 but it's lost a lot of power. it just doesn't rev like it use to.
There's no obvious reason why it shouldn't go as well as it did before. You already know it would benefit from reprogramming, but apart from that it is really worth checking that your MAF is performing properly. I consider them to be consumables really. Do you know the history of yours, and do you have access to any test gear?

[Battler]

There's no obvious reason why it shouldn't go as well as it did before. You already know it would benefit from reprogramming, but apart from that it is really worth checking that your MAF is performing properly. I consider them to be consumables really. Do you know the history of yours, and do you have access to any test gear?

I do have a stuffed MAF which is playing havoc with my LPG but no codes or symptoms though when running on petrol. New MAF is ordered from the UK.
Cheers

[Mark Adams]

I do have a stuffed MAF which is playing havoc with my LPG but no codes or symptoms though when running on petrol. New MAF is ordered from the UK.
Cheers
A scrapyard-dodging MAF will definitely mess up your system. In the early stages they don't put up fault codes, but quite often you'll see random cylinder misfire codes starting to appear.

You do need a genuine Bosch meter though, not a junky Chinese copy. The Bosch MAF does not last forever, and if it has done has done over 100,000 Kilometres (80,000 Miles) then I would replace it with a new one. Really I consider them to be consumables, and replace them as a matter of course at this mileage

On my last tuning trip to Dubai, I had five Disco 2s in for tuning, and every one of them had a shot MAF.

[Mark Adams]

Another of my clients who has done the 4.6 conversion with the bigger MAF has put up his own website about the experience. It's worth a look:

Engine and Driveline - Discovery 2 Upgrade (http://www.discovery2upgrade.com/engine-and-driveline.html)

[ozscott]

So Mark's client speaks of new ducting also. Do we know the part number of the north american 4.6 d2 MAF to plenum hose...and air box lid for that matter? Unless the hose is not worth getting because its MAF end is slightly larger but quickly funnels to the same size as the 4.0 tube...which im thinking must be the case. Cheers

Cheers

[Pedro_The_Swift]

secondary air injection is ringing bells

[Mark Adams]

So Mark's client speaks of new ducting also. Do we know the part number of the north american 4.6 d2 MAF to plenum hose...and air box lid for that matter? Unless the hose is not worth getting because its MAF end is slightly larger but quickly funnels to the same size as the 4.0 tube...which im thinking must be the case. Cheers

Cheers
I have an air box lid from a P38 Range Rover here, and the part number on it is PHB102260. This is the one that quite a few people are using, but when the number is fed into MicroCat it comes up as a complete P38 air filter box assembly.

Most people have also found that you can stretch the D2 trunk onto the new MAF by dipping it into hot water first, since the outside diameter is only 3mm more for the larger MAF.

MicroCat lists PHC000110 as being the correct part number for the NAS 4.6 Disco 2 air filter box lid as a separate component, with a retail price of 53 UK Pounds Sterling. The matching inlet trunk is listed as PHD000480, with a price tag of 57 UK Pounds Sterling. On Monday I'll see if it is actually possible to buy them over here. Otherwise a good USA breaker would be fine, and probably cheaper too.

[Mark Adams]

Well it's Monday here, so I checked the prices as promised. They are available, but only direct from Land Rover.

However the prices are a rather eye-watering price tag of 112 UK Pounds Sterling PHC000110 for the NAS 4.6 Disco 2 air filter box lid, and 75 UK Pounds Sterling for the matching inlet trunk PHD000480.

Suddenly a used P38 lid at around ?30 and a bowl of very hot water look like a bargain! :-D

[ozscott]

Many thanks Mark. Cheers