Raising boost on a td5

[RenoHuskerDu]

Howdy foks,

My td5 has a new turbo that just got put on by the dealer before I bought it. Unlike other td5 turbos I've seen here in France, the wastegate has an adjustment rod. See pic:
https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/393427_2669524542412_1385048026_33070756_132455524 1_n.jpg

To summarize quickly what I have heard here from reliable sources;
1) the td5 can make a lot more power and still be reliable
2) the exhaust manifold will however need stronger studs
3) you can safely raise the boost a fair amount
4) Discos have an overboost cutoff device that Defs don't
5) some owners remove that overboost device from their Disco

So because my turbo has an adjustment rod, I've been slowly turning up the boost and waiting for that overboost cutoff to kick in. So far I'm up three full turns on the adjustment rod. I have not put a pressure gauge on the wastegate hose yet because I haven't got a spare gauge. I suspect that the boost was initially set conservatively by the LR dealer when they put in the new turbo. The former driver was a woman :eek: as I can see by the hole her high heels made in the floormat.

What do you guys think about my plan? Is it safe to just keep going up one turn at a time until the overboost starts shutting off the fuel? When that happens I plan to back off the rod 1/2 turn until the overboost stops kicking in. I don't plan to remove the overboost protection until I have an aftermarket exhaust manifold with bigger studs holding it in.

I also have a PSI Motorsport power box installed. It fits into the standard LR connectors so no soldering was needed. The maker in Luxembourg claims 25 hp and 74 nm more from the box, which seems reasonable. Some of these chip makers make wild claims that can't be true in real life.

Thanks for any advice!

---------
Reno, France
2000 Disco 2 td5, sky blue, formerly used in Fosters Beer adverts here in France

[ericpicc]

Reno France ?
I'm from Chalon-sur-soane.:angel:
Sorry can't help you with what you have asked but I'd like to know myself.
Might be a good idea to post the question in the Defender forum on here as well.

[RenoHuskerDu]

Alsace! Where France, Germany and Switzerland collide and the women are pretty.

[mturri]

My td5 has a new turbo that just got put on by the dealer before I bought it. Unlike other td5 turbos I've seen here in France, the wastegate has an adjustment rod.
Looks like a standard Td5 turbo to me...


1) the td5 can make a lot more power and still be reliable
Indeed!


2) the exhaust manifold will however need stronger studs
No, it will need to have the interwebbing removed and some of the stud holes enlarged to accomodate for some movement. Standard Class 8.8 studs are perfectly up to the task once the manifold warping tendency is rid of, only some dudes think more make up torque is better and that's when the studs become prone to shear. Can get a fancy ceramic coated manifold but not worth IMHO.


3) you can safely raise the boost a fair amount
Yes but with your current set up power gains will be marginal


4) Discos have an overboost cutoff device that Defs don't
Hmmm... All Td5 engines have an inlet manifold air pressure sensor that feeds the ECU, this sensor is common to all electronically managed diesels and is widely known as IAT/MAP (it also measures inlet air temperature). The ECU will cut fuelling when detecting an overboost situation through the MAP sensor.

There is a difference in the way these vehicles do boost management though. Whilst both use boost pressure to operate the wastegate actuator, the Disco does it electronically through the wastegate modulator ('modulates' wastegate actuator pressure to obtain boost pressure values that best suit that particular fueling instance). On the Defender the wastegate actuator is controlled mechanically and directly by boost pressure. The wastegate doesn't 'cut-off' boost, it simply bypasses exhaust gases so that turbine rpms are kept more or less constant after full boost is achieved.


5) some owners remove that overboost device from their Disco
The wastegate modulator is known to fail & what some owners do is remove it and pipe the actuator directly to boost pressure. This effectively takes out the edge Discos have over Defos when it comes to boost management. The modulator is only about £12!!
On the other hand some owners install a gadget (Turbo Boost Box) that intercepts the signal from the MAP sensor to the ECU and 'hides' the overboost condition therefore fueling is not altered.


So because my turbo has an adjustment rod, I've been slowly turning up the boost and waiting for that overboost cutoff to kick in. So far I'm up three full turns on the adjustment rod. I have not put a pressure gauge on the wastegate hose yet because I haven't got a spare gauge. I suspect that the boost was initially set conservatively by the LR dealer when they put in the new turbo.

The former driver was a woman :eek: as I can see by the hole her high heels made in the floormat.

What do you guys think about my plan? Is it safe to just keep going up one turn at a time until the overboost starts shutting off the fuel? When that happens I plan to back off the rod 1/2 turn until the overboost stops kicking in.

Not much to be gained from doing this on a Disco for the reasons above explained. Boost is not about how much but about when.

IMHO it is wiser to first concentrate on 'engine health/life enhancement' upgrades (EGR removal, ProVent, reconditioning injectors, cleaning sensors, intercooler, etc.) before seeking out for performance mods.


I don't plan to remove the overboost protection until I have an aftermarket exhaust manifold with bigger studs holding it in.
No need to get a new manifold, can do the work yourself. See below.
http://www.aulro.com/afvb/good-oil/34318-td5-engines-studs-loom-head-removal-fpr-injectors-changes-alt-not-charging.html

Rgds
Matt

[RenoHuskerDu]

...No need to get a new manifold, can do the work yourself. See below.
http://www.aulro.com/afvb/good-oil/34318-td5-engines-studs-loom-head-removal-fpr-injectors-changes-alt-not-charging.html

Rgds
Matt

I had a look see at that removed webbing bit, which looks very interesting. That post was from 2007 ... by now have we heard back on how it has held up?

Regarding EGR, I forgot to mention that I defeated it first thing.

[RenoHuskerDu]

... There is a difference in the way these vehicles do boost management though. Whilst both use boost pressure to operate the wastegate actuator, the Disco does it electronically through the wastegate modulator ('modulates' wastegate actuator pressure to obtain boost pressure values that best suit that particular fueling instance). ...

I think that I understand that well now. This difference could explain the french folklore I reported about Disco/Def overpressure cutoff etc. They may in fact be depriving their Discos of advanced boost management just as you say. I will have to share that info with my LR mechanic mate.

By now I am up to four turns tighter on the adjustment rod. It does seem to me that max torque is up a bit more with every turn of the rod. Would you agree that the shorter rod means that the wastegate cannot vent as much pressure into the exhaust? So in effect, my wastegate modulator is still doing its job, but physically cannot open the wastegate fully, so max manifold pressure is up? (but not enough to trip the overboost).

Or maybe I am barking up the wrong tree.
:imwithstupid:

[mturri]

Re the Td5 exhaust manifold work, have done dozens of these starting more than 5 yrs ago with no failures reported to date (I'm no mechanic --just help fellow Td5 owners-- so no reputation or pride at stake).

Shortening travel on the wastegate actuator rod essentially shifts the 'zero' position on the wastegate to a 'more closed' one (less exhaust gas bypassing turbine), consequently the fully open position will be a 'less open' one. This is good for low down engine liveliness but may induce it to overboost 'upstairs' under certain full boost conditions.

Not precisely sure but believe the wastegate rod in the Disco comes with 13-14 'free' threads and can be safely shortened to about 10-11 threads. Ideally one would be doing this on a step by step basis while closely monitoring boost pressure via Nanocom or HawkEye to ensure overboost does not occurr within the range of conditions the vehicle is commonly driven through.

Engine maximum torque cannot go up by simply manipulating the wastegate actuator rod, you're just making the engine more responsive by allowing the turbo to pick up revs & reach full boost sooner (call it 'earlier torque').

Keep forgetting you have a power box... which I'm personally not in favour of since in principle they cheat to both ECU and injectors. With a magic box or remap the torque vs rpm curve is shifted left and slightly upwards (more low down torque and somewhat of an increase in maximum engine torque at full boost).


Rgds
Matt

[ericpicc]

So not far from where I'm from then.;)

[Fluids]

I went about 4 full turns ... 2x then tested, then went another 2x.

The Nanocom shows a max boost (standing start, foot to the floor, auto upshifting at 4200rpm) of about 19.5psi (peak). I have left it there, and have only once experienced a fuel cut/overboost in the last 2yrs since doing it (driving like a boy racer :) )

[RenoHuskerDu]

I went about 4 full turns ... have only once experienced a fuel cut/overboost in the last 2yrs since doing it (driving like a boy racer :) )

Hey now, that is good news. I think I'll leave it at four turns for now. No overboost here yet either. :spudnikwaving:

[mturri]

Kev,

That is about 240 kPa absolute (assuming sea level ambient pressure)... quite close to the overboost cut-off point of 242 kPa (in my books, someone knows better pls correct me!).

Now out of curiosity what is your steady full boost pressure? (i.e. @ max motorway allowed speed).

Cheers
Matt

[Fluids]

Matt .... remerbering that my tires are 4% oversize, and I have a full length (2m) Rhino alloy tray on the roof (which is a bit of a parachute) .... and they vary depending on load carried, headwind, etc ... these are as per my GPS for road speed.

AT 80kmhr ... 1800rpm ... 0.32-0.38 BAR (0.36 = 5.22psi) - speedo says 75
AT 90kmhr ... 2050rpm ... 0.58-0.62 BAR (0.60 = 8.70psi) - speedo says 85
AT 100kmhr ... 2200rpm ... 0.76-0.80 BAR (0.78 = 11.31psi) - speedo says 95

... as best as I can remember.

[RenoHuskerDu]

Your boost doubles from 80kmph to go only 20kmph faster :eek: Wow, that must be an effective parachute up there.

[Jojo]

If I am not completely wrong any increase in boost pressure/air volume is useless from the point of performance gain if you don't increase the amount of fuel accordingly. This will involve remapping of the ECU. Please correct me if I am in error.

[strangy]

If I am not completely wrong any increase in boost pressure/air volume is useless from the point of performance gain if you don't increase the amount of fuel accordingly. This will involve remapping of the ECU. Please correct me if I am in error.

Yep you are in error in part. An increase in boost will drop EGTs and provide a performance increase. In the case of the TD5 ensuring boost is optimum is noticeable. However big increases in boost without corresponding increases in fuel and changes to intercoolers will be noticeable but limited in effect.

Cheers

Sent from my iPhone using Forum Runner

[RenoHuskerDu]

At times like this I'm glad to be just a fossicker ;)

[Fluids]

It becomes more of a case of a bit more boost, sooner .... ie:more boost down low.

[fatman]

. However big increases in boost without corresponding increases in fuel and changes to intercoolers will be noticeable but limited in effect.

Cheers

Sent from my iPhone using Forum Runner

I've heard that in somecases,you can't get very high boost,unless you add extra fuel..

[Stainless]

Once a TD5 is highly tuned, the standard M8 Exhaust Manifold studs can have problems, some times even if the manifold webbing has been removed. The higher tensile and longer 10.9 / 12.9 M8 studs with spacers from JE Engineering UK are an improvement, and are basically cut-down and re-threaded High-Tensile M8 Allen Bolts.

For some, even these mods have not worked, so up-sizing the studs to M10 have finally brought the Exhaust Manifold under control. The problem with this is, even though the drilling and re-threading can be done with the cylinder head still on the engine block, it really is better done with the head off.

[RenoHuskerDu]

It becomes more of a case of a bit more boost, sooner .... ie:more boost down low.

Yes it certainly seems that way. My Disco feels spry when I am on the gas slightly or moderately. But when I need to pass a truck it feels like it has asthma.

My last rig was an hdj80 with a bigger turbo and intercooler kit. It may have spoiled me. But then it was consuming several more liters.

[Fluids]

My proceedure for overtaking is drop to 3rd, wait for lockup, then plant the LOUD pedal .... :) .... so a bit of pre planning / anticipation goes a long way. Shift to 4th, back off a bit till the TC locks again, then apply LOUD as required ....

I've been reading up about the lower stall speed TC and I think that would make a huge difference .... alot of $$$ though :(

[surfingooner]

2003 D2, I have been reading threads on boosting the turbo, I have made a few turns (to the point it cut out) on the wastegate arm and have backed off a turn or two. I recently removed the mid muffler and fit the EGR removal kit (which made significant improvements), but adjusting the turbo seems to be making no difference at all, if anything a tiny bit better at low revs, but losing a lot a higher revs - almost gutless ?


Is this common ? I am thinking the best way forward will be to buy a boost gauge where I can adjust and monitor ?


Is there anything I am doing wrong or are there any better ideas how to go about it ? I do not have access to a nanocom at present.

[sierrafery]

Hi, unplug the MAF and test drive it that way too, increased boost means higher suction too and if the MAF reading exceeds 680 the management will reduce fueling, IMO simply tightening the wastegate actuator without a remap and without the certainity that all the sensors are working well is not the best way to do things, did you clean the MAP/IAT sensor after EGR bypass? you said you removed the middle silencer but do you have a de-cat downpipe too?, cos that's more important than the middle pipe, also the depression controll valve should be replaced if it's old, ... and so on... there are too many elements involved which must be monitored so you really need a nanocom for a proper diagnose.

[surfingooner]

Many thanks, I did give the MAF sensor a bit of a clean when I removed the EGR, screwdriver in a rag which I am thinking now might not have been the best way to have done it ? So best way now will be to disconnect MAF and see if any difference.

[surfingooner]

I should add I am planning on a TD5 inside remap once the budget permits. Will get back to you. Cheers Matt.

[surfingooner]

so I disconnected the MAF this morning, and electrical connection had evidence of liquid on it, not quite sure what liquid. Did a 20 minute run and ran very slightly better, but no more 'go' from the engine. I will take some a couple of photos later as there is some oil in the area, maybe this might have something to do with it. Guessing the ultimate plan has to be to get connected to a Nanocom for some accurate data and can also set the boost correctly.

[sierrafery]

I was asking if you cleaned the MAP/IAT(the one in the inlet manifold) after EGR removal cos that one gets loaded of muck ... if with MAF unplugged is slightly better or even the same it means the MAF doesnt work as it should, check fuse F2 in engine bay just to rule it out

[surfingooner]

Thanks Sierrafery, doing more research this morning, I only unplugged the MAP sensor before work today. I did nothing to the MAF sensor. So what is best steps to go from here ? Re-connect the MAP and disconnect the MAF ? I did clean the MAP when I fitted the EGR, but with some soft cloth and no chemicals, guessing I have probably hashed this up and am going to buy some contact cleaner from Jaycar tomorrow. Am I doing this right to find out what might be wrong?


I have also contact the guy I bought the car from 2 years back and he has said I can go over and try his nanocom this weekend. Not sure if it is the right type of nanocom firstly and whilst he is obviously a very talented mechanic, not sure how technical he can be on TD5's. Sorry to be making this a long post, but what are the basics I should be doing with the nanocom ? Thanks again. Matt.

[JoeFriend]

With the nanocom you can see what reading the MAF is giving out. Idle is 50-60 and you can see it go up from there. MAP will be shown in bar just so you know.

The issue is when you turn up the boost, you can easily go over the allowed 680 on your MAF. That is the point I am at and trying to figure a way around. I would prefer to not block the signal and limit the MAF to 650 as the ECU will then just fuel for that ratio, which of course it will actually be higher. I don't get the MIL light and fuel cut off, I just get reading of zero and default mapping.

Sent from my SM-G900I using AULRO mobile app

[sierrafery]

Thanks Sierrafery, doing more research this morning, I only unplugged the MAP sensor before work today. I did nothing to the MAF sensor. So what is best steps to go from here ? Re-connect the MAP and disconnect the MAF ? I did clean the MAP when I fitted the EGR, but with some soft cloth and no chemicals, guessing I have probably hashed this up and am going to buy some contact cleaner from Jaycar tomorrow. Am I doing this right to find out what might be wrong?


I have also contact the guy I bought the car from 2 years back and he has said I can go over and try his nanocom this weekend. Not sure if it is the right type of nanocom firstly and whilst he is obviously a very talented mechanic, not sure how technical he can be on TD5's. Sorry to be making this a long post, but what are the basics I should be doing with the nanocom ? Thanks again. Matt.

The only relevant test is to unplug the MAF, if you feel improvement it means the sensor is fubar'd, by unplugging the MAP you can't really rule out anything only make it worst cos it has the IAT reading too and it will go on a reduced boost default... did you check fuse F2?, with nanocom first check faut codes, if there are any remember them and clear all then go for a ride with nanocom on inputs fueling or instruments and watch readings, normal readings are shown here http://www.aulro.com/afvb/2424076-post2.html , then read codes again to see if there is any current one and report back.

[sierrafery]

With the nanocom you can see what reading the MAF is giving out. Idle is 50-60 and you can see it go up from there. MAP will be shown in bar just so you know.

The issue is when you turn up the boost, you can easily go over the allowed 680 on your MAF. That is the point I am at and trying to figure a way around. I would prefer to not block the signal and limit the MAF to 650 as the ECU will then just fuel for that ratio, which of course it will actually be higher. I don't get the MIL light and fuel cut off, I just get reading of zero and default mapping.

Sent from my SM-G900I using AULRO mobile app
1. MAP is shown in KPa in inputs fueling and that's more relevant, only ''turbo pressure'' is shown in Bar by nanocom on instrument mode but that's a calculated value which is not very accurate.

2. the MAF should not go over 680 if the sensor is good and there's no boost leak even if the wastegate is tightened cos at around 670 the MAP should reach the 242 overboost limit before that(unless there's a boost box fitted), so if the MAF goes above 680 without a boost box then something is wrong and needs investigation, usually '"tired" MAF or too high alternator output

3. the MIL can be triggered in only two cases , by throttle position sensor and crankshaft speed and position sensor complete failures, the MIL has nothing to do with MAF or MAP or other management components whatsoever(it will only flash on the purge sequence)

hope this helps

[surfingooner]

Ok, I will re-attach the MAP and disconnect the MAF and report back. I have printed off the nanocom 'hit-list' and going to see my man on Sunday and will report back after. If his machine is no good then I will try and find an aulro member who is local to Warrandyte. Getting there slowly, with thanks. My history was rebuilding Beetle engines (and other bits of Beetle's) with my RAF Engineer Uncle 20 years back in UK. Now going solo and loving having a vehicle I can work on and play with again. Other car is a turbo diesel VW Passat - say no more !!!!

[JoeFriend]

1. MAP is shown in KPa in inputs fueling and that's more relevant, only ''turbo pressure'' is shown in Bar by nanocom on instrument mode but that's a calculated value which is not very accurate.

2. the MAF should not go over 680 if the sensor is good and there's no boost leak even if the wastegate is tightened cos at around 670 the MAP should reach the 242 overboost limit before that(unless there's a boost box fitted), so if the MAF goes above 680 without a boost box then something is wrong and needs investigation, usually '"tired" MAF or too high alternator output

3. the MIL can be triggered in only two cases , by throttle position sensor and crankshaft speed and position sensor complete failures, the MIL has nothing to do with MAF or MAP or other management components whatsoever(it will only flash on the purge sequence)

hope this helps

Well, my brand new genuine MAF is going above 680 very quickly, so curious to figure out what the problem is there. Any ideas???

Sent from my SM-G900I using AULRO mobile app

[sierrafery]

How much are the AAP, MAP and voltage readings when this happens.... read MAP in inputs fuelling not boost in instruments mode, also does your MAF has Siemens stamp on it?, cos there are some fake so called OEM or genuine MAF's on the market


btw, do you have snorkel?

[JoeFriend]

AAP is normal, around 103. Voltage maxes out at 14.4 or so from memory.

Will have to check the MAP when I drive next.

Yep, I have a snorkel - does that make a difference?

Sent from my SM-G900I using AULRO mobile app

[surfingooner]

So I reconnected the MAP and disconnected the MAF, first time I put my foot down when warm and the fuel limiter cut in. adjusted the waste gate back about 3 turns and improved. Power delivery much better. I the put foot down at 60 kms and got to 80 and pretty much stayed there, revving but not much else. Pulled over again and wound adjuster back a couple more turns. Seems better, will drive more tomorrow.

So at this point can I take the MAF needs a clean / replacing ? And also feeling a bit lost as to where the waste gate adjustment should be ? Will this all be resolved when get access to the Nanocom ?

[sierrafery]

adjust the wastegate rod as to count 10 threads left out from the locking nut and if it overboosts back one turn at a time untill it doesnt, if you get overboost at 13 threads left which is the standard setup it means the wastegate modulator is gone then unplug it, if it's not blocked closed it should be oprn unplugged so it will be like bypassed... off course that a nanocom session will reveal some issues if they are

[sierrafery]

AAP is normal, around 103. Voltage maxes out at 14.4 or so from memory.

Will have to check the MAP when I drive next.

Yep, I have a snorkel - does that make a difference?

Sent from my SM-G900I using AULRO mobile app

If the snorkel's intake is toward the front it might increase the flow at high speeds in some cases(i've seen a few) so make a test with it turned back to see if there's any difference or not.

[JoeFriend]

If the snorkel's intake is toward the front it might increase the flow at high speeds in some cases(i've seen a few) so make a test with it turned back to see if there's any difference or not.

I will give it a try when I drive on Thursday, I thought about it but figured that the ram effect cant be that big, and it seems to happen more when I put the right boot in.

Sent from my SM-G900I using AULRO mobile app

[surfingooner]

I wound back the adjustor to 10 threads and have left the MAF disconnected. Car running better, I have bought some contact cleaner, so not sure if I should clean the MAF unit or do anything now prior to getting hooked up on the nancom on Sunday ?


I will report back next week and thanks for help as always.

[JoeFriend]

Tried the snorkel in reverse trick, didn't work but I now have a sweet induction sound so am going to leave it that way.

Sent from my SM-G900I using AULRO mobile app

[Tombie]

If the snorkel's intake is toward the front it might increase the flow at high speeds in some cases(i've seen a few) so make a test with it turned back to see if there's any difference or not.

Makes no difference on a TD5. The ram air effect is essentially myth.

[Eevo]

Makes no difference on a TD5. The ram air effect is essentially myth.

nonsense. it has an effect, just need to be going over 200 to notice it.

[Tombie]

nonsense. it has an effect, just need to be going over 200 to notice it.

Exactly :D No production LR has ever seen it happen :cool:

[surfingooner]

Ok, so I got hooked up to a nanocom yesterday, warm day and readings as follows, not my bag this, so not really sure what it all means (answers in blue) ?


(for all the presented figures +/- 5% is acceptable)

MAF(air flow) = 55-60 (54) at idle growing with revs up to 600 or above at 3000+rpm (315) ... to not exceed 680 then it cuts out

AAP(ambient pressure) = real ambient pressure on barometer in kPa,(100) around 100 must drop up to 2-3 units to 3000+rpm, more decreasing of that value related to the acceleration should indicate that the air beyond the filter is less than required.

AAT(ambient temp) -only Eu3/15-16P engines = real ambient temp on thermometer

MAP(manifold absoolute prssure) = with AAP at idle growing to 230 at full load (216 @ 3,300 rpm)... TURBO PRESSURE = 1.3 at max load (101 kpa at idle)

CYLINDER BALANCE = +/- 4 is good - all Ok

IAT(inlet air temp) = AAT + 10 to 30 depending on outside temp, engine coolant temp and boost(meaured with the car's coolant gauge at middle)...also it can be much higher if non-cooled EGR is still fitted

COOLANT TEMP = 70 - 115 (80) gauge stays at the midddle, the gauge will go to red zone only at 120 and the electric cooling(aircon) fan kicks in at 110 and stops at 105... normal operating condition around 90 (91.9 after run)

FUEL TEMP = around 10 less than coolant temp (84.9)

THROTTLE
ACCEL. WAY 1 - about 0.3 - 0.8V with the pedal released, about 4.7V with pedal to the maximum position
ACCEL. WAY 2 - about 4.7V with the pedal released, about 0.3V with pedal to the maximum position
ACCEL. WAY 3 ? this track must have values very near to the second track.(only 15P-16P engines)
ACCEL. SUPPLY ? this value must stay between 4.9 a 5.1


So I am thinking this went pretty well (?), interesting that my MAF only read 315, does this mean it does need a clean ? Having lengthened the wastegate adjustor back (now 11 threads visible) I had re-attached the MAF sensor on Friday and hadn't made any noticeable change, so thinking was that it was working OK. Thinking I am not going to play with the turbo boost anymore and concentrate on saving for my re-map.


Welcome any feedback anyone has to these readings as I am totally out of my comfort zone here. Many thanks as always. Matt.

[sierrafery]

Hi, the MAF reading is very low ar high revs, at that difference i doubt that a clean could help you nless it's very dirty or there's a restiction in the intake though the MAP should be lower too, IMO a new one is required.

[sierrafery]

Makes no difference on a TD5. The ram air effect is essentially myth.
I dunno what that "ram effect" is in reality or how can it be scientifically linked to a car's intake. What i said is based on nanocom readings with snorkel intake directed both ways... the difference was between 5 - 30 units starting from around 90km/h the higher the speed was the greater the difference, made this test on 3 different td5's and one of them which was the most tuned(stage 2 with direct exhaust and boost box on std tyres) exceeded 680 at 135 km/h, swapped MAFs and did the same then topped up at 660 with snorkel turned back. I agree it's not physicaly noticeable while driving except that case when it cuts out, but the readings are quite relevant though I'll make some records next time when i'll have the chance to do that or do it yourself if you have nanocom and watch the difference

[surfingooner]

I met up with Wardy1 on Saturday who kindly linked up his Nanocom and we went for a drive, MAF read up to 600, but Wardy1 thought it was 'gutless' at the higher revs, and that must be a fueling problem, most likely MAF, we cleaned mine out, and then swapped his over and went for another drive. It was better, but did not really make the difference we were both expecting. Better than mine though.

Is there anything else I should be looking at, Wardy1 mentioned the fuel pump, but we didn't have the time to dig any deeper. Thanks Wardy1, he was a great help and more than happy to share.

[surfingooner]

Update, I cleaned the MAP sensor yesterday with contact cleaner and has made a significant improvement.


More grunt as it revs and the Disco is changing gear at different placed than usual - much happier. A fair bit of black liquid came off when I cleaned it and also the electrical connection had some oil in there. For a 5 minute job, I recommend everyone should do it !

[surfingooner]

Hi, the MAF reading is very low ar high revs, at that difference i doubt that a clean could help you nless it's very dirty or there's a restiction in the intake though the MAP should be lower too, IMO a new one is required.


So here we are quite a few months on and still playing around and cannot get the car 'right'. I replaced the MAF with a second hand one which I am told had been tested and was working, it made a difference, but that was about a year ago, the fuel pump was changed shortly before I got it, I have changed the fuel filter as well as the boost control valve.


I turned the boost up recently and car going better, but when I go up hills, or put foot down, it has started down a kangaroo impersonation, it wants to go quicker, but something is holding it back.


Boost is at 21 psi (stage 2 re-map) from TD5 Alive when I turn it up. I have bought some contact cleaner so will again clean the MAF and MAP.


I did disconnect the MAF a couple of months back, and it did not go as well, so I ticked that off my list, but again thinking it might well be not working properly ?


What are my next options, I have been reading the excellent thread about bridging the MAF, is this something I could try to rule out the MAF ?


Or there anything else I might have missed ? The car never wants to get past 2,900 rpm and sits there. Frustrating....and any guidance would be very greatly received. Matt.

[SPROVER]

Are you sure it's not going into over boost? Mine will Rev freely to 4000 if i really want to push it. But i run a boost box and 23 psi.

[surfingooner]

Are you sure it's not going into over boost? Mine will Rev freely to 4000 if i really want to push it. But i run a boost box and 23 psi.


Possible, but when I tweaked up to this range before it would just go into limp mode, never this kangarooing thing, it is like some kind of limiter, I will back off a turn or two and report back.

[sierrafery]

Check the pipework connected to the wastegate modulator and if it's OK take the pipe from the modulator's bottom and connect it directly to the wastegate valve...if it'll run OK this way you need a new modulator

[sierrafery]

Check the pipework connected to the wastegate modulator and if it's OK take the pipe from the modulator's bottom and connect it directly to the wastegate valve...if it'll run OK this way you need a new modulator

[PhilipA]

Just to clarify an earlier post on this thread, my understanding of the modulator is that it is like an electronic "Dawes valve" in that it prevents air pressure getting to the wastegate diaphragm until 15PSI , to reduce wastegate creep and therefore increase boost at part throttle.

IE it has an electronic valve inside that is closed until the ECU senses 15PSI, presumable from the MAP and then it opens.

My boost is now about 20-20.5 PSI and I have no surging etc after 15PSI, although it sdoes seem to hit 20.5 then drop back about 0.5 PSI.

Regards Philip A

[surfingooner]

Thanks for the help. I set to work at the weekend and discovered I had not clipped the MAF sensor back after doing some remedial work after my boost gauge stopped working when one of the pipes to the modulator had come loose.


Hadn't noticed much difference to performance without it, so was guessing it was this that was causing the "kangarooing'. Since I have cleaned up the MAF and MAP with contact cleaner and would the boost back down to 19psi. The car is definitely running better generally, but still not satisfied on the 3,000 rpm rev range.


Yesterday I was pulling onto the Eastern Freeway, put my foot down and watched the revs and boost, again it got to 2,850 rpm and boost at 19psi and then slowly nudged it's way to 3,050 which took about 4 seconds with very little increase in speed, it then changed to 4th and whoosh, in no time I was at 115kmh.


Obviously once it changes gear to 4th, we are back in the turbo range, hence the band of acceleration I am guessing. Is this normal for an auto, I think not ?


I am not a foot to the floor driver at all, I know I can trip the over-boost if I put foot to floor going up one of the very steep hill round where I live (if anyone knows Warrandyte they will know what I mean), but choose not to as it is just not worth the effort to achieve a very small increment in speed, and this also means winding the boost back further.


What to do ..... ??

[PhilipA]

I just reread this thread and although I am not a good proof reader, I think you do not mention having a look at the fuel pump and filter.

If the car has had the washers changed in the injectors, it is usual for the filter at the base of the fuel pump to be blocked up with black crap.

Have you changed the fuel filter?

Another possible mechanical problem is that the basket filter in the head under the fuel pressure regulator can get blocked.

The TD5 auto in EU3 form should rev to 4200 RPM before change. When stock the last 1000 is pretty tedious but with increased boost and map , they go pretty well.
Regards Philip A

[nismine01]

Right, a couple of things, the performance when in 'the range' of torque as you have found is one thing.

I fitted a new Torque Converter from Torque Converter Technologies in Melbourne (TCT), it has a larger lock up clutch and locks earlier (lower revs) than the standard one. This has helped keep the engine in the 'rev range'.

It does not alter gear change points but as the TC is locked it helps.

I have for a long time wondered about the pressure take off point for the turbo pressure reading, it appears to be in the vicinity of the turbo, my thinking is that if the reading was taken from the back of the intake manifold all the resistance and delays caused by the intercooler and plumbing etc would be taken out of the equation and a truer perhaps slightly quicker performance could be had with very little else done.

Right track or??????

Cheers, argue/discuss on.

Mike

[sierrafery]

I have for a long time wondered about the pressure take off point for the turbo pressure reading, it appears to be in the vicinity of the turbo, my thinking is that if the reading was taken from the back of the intake manifold all the resistance and delays caused by the intercooler and plumbing etc would be taken out of the equation and a truer perhaps slightly quicker performance could be had with very little else done.

Right track or??????

Cheers, argue/discuss on.

Mike
IMO the relevant pressure reading is as close to the engine inlet as possible cos that's what the engine gets in reality, the MAP sensor is exactly where it should be from this point of view, measuring boost near the turbo while you are not certain it gets untill the inlet might not help too much if you see what i mean

[surfingooner]

I just reread this thread and although I am not a good proof reader, I think you do not mention having a look at the fuel pump and filter.

If the car has had the washers changed in the injectors, it is usual for the filter at the base of the fuel pump to be blocked up with black crap.

Have you changed the fuel filter?

Another possible mechanical problem is that the basket filter in the head under the fuel pressure regulator can get blocked.

The TD5 auto in EU3 form should rev to 4200 RPM before change. When stock the last 1000 is pretty tedious but with increased boost and map , they go pretty well.
Regards Philip A



Thanks Philip, the fuel pump was replaced not long before I bought the car, at around 220k, and it has now done 270k, and yes I also changed the fuel filter when I last did a service about 5k ago, I also changed the piping to and from the boost control modulator, and to wastegate valve.


There is absolutely no way I could get the car to 4,200 rpm currently. I am interested in the upgrade torque converter, but am guessing we are talking big(ish) dollars, but I just want to get the most out of what I have now, I have pretty much replaced a lot of it, albeit the MAF was not new, and I know the car has more in it, I just have to find out how.


How do I get to the basket filter ? Never had a look there ? Thanks again. Matt.

[PhilipA]

How do I get to the basket filter ? Never had a look there ? Thanks again. Matt.

It is under the fuel pressure regulator. When the fuel pressure regulator is removed you see a fat Oring in the head. The basket filter is under the oring.

Regards Philip A

[surfingooner]

It is under the fuel pressure regulator. When the fuel pressure regulator is removed you see a fat Oring in the head. The basket filter is under the oring.

Regards Philip A



Thanks Philip, is it a tough 'get to' job ? I bought a second hand unused Cooper Tyre just before Xmas and as it turns out he was a Disco owner, lived 10kms away, same year, diesel model and colour !! He has had his tuned also, so going to take mine over in next couple of weeks and drive each others and compare notes.


I will get there eventually ! Was driving over the Xmas period and have decided to dream that I want to get more performance out of the TD5 as my New Year Resolution, I want to keep my Disco forever, the 3's and 4's do not excite me enough (maybe a 5 one day), and I just love the look of the 2, no plastic, real car.


So I think the next two jobs will be firstly to upgrade the torque converter as Mike has suggested, or replace, and then fit an uprated intercooler. Having got rid of the EGR, Mid box, and with fuel stage 2 re-map, I think they are the next best mods to do at a reasonable cost ?


But I will firstly have to follow through and check out the basket filter.


Happy New Year all. Matt.