Highway cruising 300tdi

[wllgbsn]

A few questions for the gurus (or those who have tried) to help their 300tdi disco with highway cruising...
1. Is 3000 rpm normal for around 100km/h in a 300tdi auto (it was a 95 model which i fitted with the newer smaller alternator puller which I suspect has messed with the rpm reading a bit I realised i cant for the life of me remember the rpm before I fitted in (mainly because the cable to the taco wasnt connected properly [bigsad]).

2. Would fitting a larger intercooler (allisport double core) and tuning properly (at say MR auto) help it run at highway speeds where it currently labours at around 3000rpm at 100km/h. I rarely run it any faster than this except maybe on the big downhills ;).

3. Would a hybrid turbo help at the high end as well (as you can tell most of my wishes for power and drivability increases are around 85 km/h+. Up to this point i am very happy. I’m talking about one of the ones from turbo rebuild in the UK. The allisport ones are a bit pricey imo.

4. Is a slight whining noise, as in i can move my head a couple of cm and no longer hear it (and no, no one in the passenger seat) when under load normal?

Cheers for any info. Will

[edddo]

There are a lot of threads about this so try searc..but

No 3000 at 100 is too high..more like 2300 depending on tire size

Is the auto box moving into lock up around 80? If not, then 3000 at 100 makes a lot of sense and it is a transmission fault.

The generally accepted way to go about this with a 300tdi is

Get egt gauge
Adjust FIP
Mostly this is sufficient but if not then.
Bigger intercooler
Re adjust FIP ( bigger intercooler on it’s own without fip fiddling does little)

If you need more then

There are also tricks with adjusting boost
Then if you still need more then you are into the realm of better turbos including the hybrid style you mentioned.

[pop058]

100kph is normally around 2400 revs in my 300 TDI auto. IIRC the tacho signal come from the alternator so your replacement maybe giving a false reading.

[87County]

Sounds like the alternator pulley to me also - just remember that if you install the correct one you'll probably need a longer belt.

[wllgbsn]

Yeah i think it might be the alternator pulley too as when i calculate the ratio difference 3000 rpm at 49mm pulley diameter will mean 2400 RPM at 61mm diameter pulley. Hopefully thats it anyway. My auto gear up to 4th is almost smack bang on 80 as well. I wish it had a 5th though, then it would be perfect.

I guess my main question is whether any of the above changes (intercooler... turbo...) actually made a real world difference in 4th. I already have an egt and the most i could get it up to was 620 at id say about 105 yesterday on the sunshine coats Bruce highway (I think my top speed is 120 km/h on the speedo so about 110 in real world numbers). It has crept up to around 650-680 on big inclines (gateway bridge, bunya mountains) so i’m Somewhat hesitant to change my fueling without changing components like intercoolers first. I just feel it needs a bit extra due to the weight she’s carrying (its got “the works” in bullbar, winch, rear bar, rock sliders, big roof rack, lights, water tank, shelves in the back, dual battery etc.

[Bmachining]

Turbo, intercooler, changes will make very little difference to cruising at a constant speed. They will help when accelerating.

If the exhaust is restrictive it may hinder it a little.

I have adjusted my injector pump and boost on my 300tdi manual, it is much perkier now! Huge difference.
I wouldnt mind a VNT turbo for the increase in boost low down in the rev range.

[BathurstTom]

I have a 96 300tdi manual D1. It has the Allisport Uprated intercooler and, as from about 4-5 months ago, a Hybrid turbo. When I fitted the intercooler, it has about 10% more power and will hold a little longer going over a hill. The Hybrid doesn't give it a lot extra power, but the power does come in a little lower in the revs, maybe 500 revs lower. The best description that I can think of is it is the difference between having a fairly heavy box trailer on when going over hills.

It definitely makes it more drivable and helps it stay at cruising speed a lot easier. Mine will easily sit on 120 or so without having the fooot all the way to the floor. Not saying that it will go much faster than that, but it is doing it within itself if you know what I mean. My car has nearly 304k on it.

Tom

[wllgbsn]

Awesome, thanks Bmachining and Tom, some real world feedback is always excellent :)I think my course of action will likely just be an intercooler and FIP tweak at MR auto to help with some responsiveness. Ill see how that goes then consider some changes to the boost and or turbo unit and exhaust if I still feel I need a bit more responsiveness.

Tom mine is catching you up! 301k kms :). Done about 40k in the last 2 years after doing 35k in the 15 years beforehand and 230k in its first 8 years or so of life. She’s certainly had a new lease on life since ive taken her on :). Just trying to give her a fighting chance at keeping up with the highway traffic and not cause a backlog a mile long on every hill.

[Red90]

You should be able to happily sit at 120 all day long. If you can’t you need to fix what is broken.

[mrb505]

You should be able to happily sit at 120 all day long. If you can’t you need to fix what is broken.

Don’t know about happily Sure your talking about a 300tdi?

[Rick1970]

You should be able to happily sit at 120 all day long. If you can’t you need to fix what is broken.

This.
Never driven a 300, but my 200tdi will certainly cruise at 120 if so desired.

[edddo]

Cruise at 120...hmmmm
Yep unladen without too many hills, certainly with original size tyres.
Trip load, over size tyres, hills, racks, winches etc...only in flat country with no headwind.
I hope for some improvement when I fit my hybrid turbo and retune.
But it is just a 300tdi..happiest cruising closer to it max torque band...that is around 1900 to 2500ish

[Red90]

Don’t know about happily Sure your talking about a 300tdi?

Yes. I was driving these things when they were new. Nobody had any trouble on the highway back then. All the people having problems driving at proper speeds have engines in poor tune.

[edddo]

Yes. I was driving these things when they were new. Nobody had any trouble on the highway back then. All the people having problems driving at proper speeds have engines in poor tune.

..and more weight and bigger wheels and a few hundred extra thousand kms.

[manic]

Check compression is good, injector spray test, flush out the IC, you should have 14 - 16psi at the manifold.

If you are up to defender size tyres on auto and heavy, consider defender 1.4 tcase ratio.

Uprated intercooler will allow more fuel for noticable improvement, the double core IC is a drop in replacement. Done in a jiffy.

If your turbo impeller is in good form, no play, no oil seal issues - save the money/hassle. Look to upgrade it when it starts to fail.

[Red90]

..and more weight and bigger wheels and a few hundred extra thousand kms.

Does not matter. I test and fix up people’s old TDIs all of the time. Taking them up to 120 is the first test to see if the engine is adjusted properly. When they have trouble getting there you know they need work.

[mrb505]

Taking them up to 120 is a lot different to happily cruising along all day at 120
I reckon they feel sweet at 95 true speed.

[DiscoMick]

I agree. Our 300Tdi D1 auto was happiest when towing at 95-100 kmh. Used a lot less fuel too.

[Fausto79]

I want one of those hybrid turbo billets you can get. and a double core IC. if i went down that path though i would also improve my air intake system, as i think it is fairly restrictive. my exhaust is straight through, but if it wasn't i would do it too. the other thing i would do at the same time seeing as you need to pull exhaust off is to ceramic coat it and the inlet manifold. there is a lot of heat transfer between the two. this would reduce under bonnet temps too. can also tape your dump pipe with exhaust tape.

that's just my opinion. won't make a huge difference but i'm the sort of person that if i start pulling things apart etc. i go all out so that it doesn't have to be done again in a long time.

i have already plans for it. put a donaldson filter housing and filter to replace the square housing now. that would allow the snorkel to come straight in without silly turns and shape changes. hybrid turbo. ceramic coated pipe from housing to turbo. ceramic coat inlet and outlet. tape dump pipe. make a new pipe from turbo to IC and coat that too. double core IC. vents in bonnet. also put in a boost controller so that i can get it up to 18psi.

what difference would all that make. the boost, turbo and IC probably noticeable, all the ceramic coating probably very marginal difference. the better air inlet maybe marginal but i think it would complement the hybrid turbo.

in all would it be worth it in terms of cost? probably not completely. but it's my car and i will do what i want to it and in my little world it will make me happy and to me that makes it worth it. the nice proper cold air going into the engine should help it i think. even when the car is fully warmed up on a hot day, there should be minimal heat transfer between hot and cold components and let her continue to run sweet.

on a side note, the ceramic coated exhaust might make your EGT come up a bit, but apparently hotter exhaust makes exhaust gas speed up. i think the engine temps would still be lower because of the cooler charge air. so technically you could go past the 720C mark but it wouldn't necessarily mean that your engine is at the piston melting limits. not that i would take it there and i hold no responsibility for the above comments. it's just an assumption i made which one of the more knowledgeable people here could perhaps prove me right or wrong.

[Rick1970]

Cruise at 120...hmmmm
Yep unladen without too many hills, certainly with original size tyres.
Trip load, over size tyres, hills, racks, winches etc...only in flat country with no headwind.
I hope for some improvement when I fit my hybrid turbo and retune.
But it is just a 300tdi..happiest cruising closer to it max torque band...that is around 1900 to 2500ish

Happiest at 95-100 yes, but will cruise at 120 easy.
265/75 muds, 1.4 trans, b/bar winch roof racks steel rear bar fridge and a bit of gear in back.

[edddo]

Happiest at 95-100 yes, but will cruise at 120 easy.
265/75 muds, 1.4 trans, b/bar winch roof racks steel rear bar fridge and a bit of gear in back.

With std turbo and correct speedo?
Can you hold speed up a decent hill too..and keep egts under control?
I am very impressed if so.
Mine will pull about 135 absolute max with moderat load, no rr.
Cruising laden ( I mean decked out for a trip with rr 160 litres fuel etc) at a true 120...no way.
Not that and keep egts under 700...no way.
What is your tune/mods/kms?

[Rick1970]

206k, std turbo 16psi, diff inter cooler (not sure on make), slight pump tweek, max egt seen is 680-700 on a big hill. Holds speed ok, all things considered

[Fausto79]

206k, std turbo 16psi, diff inter cooler (not sure on make), slight pump tweek, max egt seen is 680-700 on a big hill. Holds speed ok, all things considered

hottest i ever got mine was 650C and i was crying. going up a big hill with head winds and camping loads. i was only going up at 100kmh though and eventually was at 80kmh by top of hill, partly due to me backing off throttle because of the 650C. i'm too kind to her.

[incisor]

I reckon they feel sweet at 95 true speed.

my last two have their sweet spot around the 105kph mark

my 130 pulling a 1 tonne van has no trouble cruising at 105kph

the usual hills and headwinds caveats apply but in my experience the 300tdi pulls as hard / well as a 3.5 v8 or 4bd1-t county up the same long hill, if not slightly better... and you don't need a fuel stop half way up the hill :p

[Robmacca]

Happiest at 95-100 yes, but will cruise at 120 easy.
265/75 muds, 1.4 trans, b/bar winch roof racks steel rear bar fridge and a bit of gear in back.


I see you're running a Defender Transfer Case (1.4). I've always been interested in this and I reckon it's the way to go but it does mean your engine is revving a lot more so not sure what that does to your economy. I assume u have to use a GPS to check your speed ??

[edddo]

Well based on all that I think I am too kind to mine too.
Rarely see over 550 even with FIP at the aggressive setting - might have to up the fuel a poofteenth.

[Rick1970]

I see you're running a Defender Transfer Case (1.4). I've always been interested in this and I reckon it's the way to go but it does mean your engine is revving a lot more so not sure what that does to your economy. I assume u have to use a GPS to check your speed ??

Gps yes, 100 indicated = 104 on gps.
Revs a tad higher than would be standard, but ok on 32" tyres. Had it on 31's (30.4") tyres for a bt, prob a bit too small with a 1.4 trans.
Havn't checked economy properly, but would be around 10/100. Will have to block off sill tanks and check properly one day.

[mrb505]

my last two have their sweet spot around the 105kph mark

my 130 pulling a 1 tonne van has no trouble cruising at 105kph

the usual hills and headwinds caveats apply but in my experience the 300tdi pulls as hard / well as a 3.5 v8 or 4bd1-t county up the same long hill, if not slightly better... and you don't need a fuel stop half way up the hill :p

85-90 feels good in my 130 and let’s me have a good sticky beak as I get along

[Robmacca]

Gps yes, 100 indicated = 104 on gps.
Revs a tad higher than would be standard, but ok on 32" tyres. Had it on 31's (30.4") tyres for a bt, prob a bit too small with a 1.4 trans.
Haven't checked economy properly, but would be around 10/100. Will have to block off sill tanks and check properly one day.


WOW, I would have thought it would be the other way around and even a little bit worse like 100kms on speedo but like 90 on GPS.... Is yours a Manual or Auto?

[edddo]

Yeh also thought it would be other way around.

[Rick1970]

WOW, I would have thought it would be the other way around and even a little bit worse like 100kms on speedo but like 90 on GPS.... Is yours a Manual or Auto?

Manual. Speedo drive is on transfer output from memory, so shouldn’t effect readings. Tyre size and diff ratio changes will vary it.

[mrb505]

My 130 used to read 100 but only doing 90 until I replaced the blue cog with a yellow one in the speedo drive now when the speedo says 100 I’m doing 102 that’s with 235/85/16 tyres

[Fausto79]

There are online calculators which work out your speed based on original size road tires compared to new size. Possibly with ones which take gearing ratios into account too.

My manual D1 tdi has 245/75/16 and the speedo now reads about 94kmh when doing 100. Revs in 5th gear at that speed are about 2250. Before closer to 2500.

I find when i sit on 90 on speedo (so about 95ish real speed) I’m in the sweet spot. At 100 real speed i get an annoying rattle as well. So ruins the feeling.

[Robmacca]

Manual. Speedo drive is on transfer output from memory, so shouldn’t effect readings. Tyre size and diff ratio changes will vary it.

Here's a couple of pics from ashcrofts website:

The only difference in the data enetered was the Transfer Gear Ratio 1.41 vs 1.21. There's quite a bit of difference in the revs at 100kms

[Rick1970]

That sounds about right.
In my case std @ 100 would be 2400rpm, 1.22 hi transfer and 29” tyres, 2500 with 1.41 trans and 32’s

[DiscoMick]

I assume you know the vehicle is unroadworthy and insurance might be voided if the speedo reads lower than the actual speed. Just saying...

[pop058]

my last two have their sweet spot around the 105kph mark

my 130 pulling a 1 tonne van has no trouble cruising at 105kph

the usual hills and headwinds caveats apply but in my experience the 300tdi pulls as hard / well as a 3.5 v8 or 4bd1-t county up the same long hill, if not slightly better... and you don't need a fuel stop half way up the hill :p

I'll second that. [biggrin]

[AK83]

....

I find when i sit on 90 on speedo (so about 95ish real speed) I’m in the sweet spot. At 100 real speed i get an annoying rattle as well. So ruins the feeling.

LOL! those annoying rattles!
Easy one to fix was the transfer case lever boot covering frame. First rattle/zing I located and fixed. I wedge 4 slices of soft foam in all 4 edges and fixed that one.
Next one was the rattle from the centre console to base of dash interface, again some foam just wedged in between(screwdriver) fixed that, then the fun started!

I used to have one smack bang at about 1750 at the exact point where 4th lockup(TC) happened, at 80k/h(auto obviously).
This one was both rev and throttle dependent light throttle and 1750RPM, right on 80k/h.

Turned out it was the flapper thing inside the drivers central vent. had to pull the centre dash section out about 10 times to finally fix it.
Used all manner of stuff from cut rubber orings on the flap shaft, to duct tape, to straws .. and just about anything I could think of to stop it vibrating.
Only fix was to bash the bejesus out of it with a hammer and long tube to bend the flap on it's spindle just a little without bending it too much it didn't operate!.

sorted.

Only problem was that in stopping that vibe(now totally fixed) it masked the other annoyance .. the passenger seat vibrates(zings!) at about 90k/h now when no passenger. removed it, bashed it, thought it was the seatbelt clip, .. nup! it's the actual back rest. When I place my left hand on the grab handle, it stops.
So I'll have to remove seat again and bash the other bejesus out of the backrest to seatbase pivot soon.

my auto tdi has a sweet zone. anywhere between 80-100 now, depending on road surface more than anything else. .. Oh! and as long as I keep my hand on the passenger seat back rest(for now)[biggrin]

[wllgbsn]

Wow! Cheers for the responses everyone.
I really appreciate the dialogue everyone has brought to the table (although i will admit i had a chuckle at the comment about doing 120 comfortably in a 300tdi auto D1). Maybe once, but not in recent history. .This girl has pulled a 3.5t van around australia 2.5 times (third time head failure somewhere in NSW) by the previous owner and had no mods except for a uhf. Now she’s heavy as a brick and i wouldnt dream of doing 120, ill be happy with 110 for overtaking, the sweat spot is between 90-100 imo.
BTW saying there’s something wrong with a 300tdi if it cant sit at 120 comfortably all day is a bit rich, thats 40km/h over the entry into 4th in an auto, you would not be able to maintain that on D’aguilar let alone Bruce highway on a long stretch of hill on the sunny coast (not to mention malany).
My hope of the double sized intercooler and tune at MR (Ireckon they would have told me or the previous owner (my old neighbour) if something major was wrong in its many trips in 24 years too with how it was running ;)) is to simply regain some of the drivability which has been lost with all the mods Ive made. For those who are somewhat interested in what kind of weight the vehicle has had added I’ll try my best to add it below :)
Bullbar - 65kgs
Winch - 35kgs
second battery - 35kgs
Light bar - 5kgs
4x 9”lights - for those who have seen my vehicle it is apparent that wind resistance is another feature with a huge rack and 4 9” lights strapped to the rack - 35kg
roof rack - 60kg
solar panel - 10kg
rock sliders - 35kg
rear bar - 40kg
water tank (full) -80kg
hot water system - 15kg
tools and recovery gear - maybe 50kg
draws, fridge and shelves - maybe 75kg
Theres probably more small stuff like gauges, aerials, uhf units and gizmos but its pretty far from stock. If your doing 120km/h with all this stuff kudos to you, especially if your doing it on stock intercooler and fuelling.

[AK83]

Strange how a little mod here, and a small accessory there all add up to make an overweight monster.
Not that a D1 could ever be regarded as an overweight monster tho! .. as opposed to Patrol and Cruiser type bloat.

I recently went over a weighbridge in mine(auto tdi) and eyes popped when I saw 2360kg on the scale!
Never had a 2300 kg car before! 1980kgs max for the Frontera I had, 1950kg for the Rodeo, and the RRC was just a tad over 1700kgs I remember(dunno what kerb weight it was supposed to have, but half it's steel body had integrated back into the earth from whence it originated!)

Anyhow, 2360kgs included full tank, and about 100 kg of some tools and bits and pieces in the back, and I'm 100kg too. Take out 25kg for driver and -100kg and that takes it closer to 2235kg
And mine is pretty much bog std looking except for the bull bar only external mod of note and extra battery(up front).

Rave reckons weight of a 5 door tdi = 2100, with a 75kg driver.
so I'm 135kg over std, which kind'a sounds about right.
steel bullbar and second battery is about all the heavy weighted stuff I have.
If bullbar is 65kg, I think my second battery is 20kg(ie,. 85kg in them) then I have about 50kg of just 'all kinds of stuff' in there somewhere [bigwhistle]

Didn't think to do each axle too.
But at that rate, I think I have about 400kg of carrying capacity available.

[edddo]

That sounds about right.
In my case std @ 100 would be 2400rpm, 1.22 hi transfer and 29” tyres, 2500 with 1.41 trans and 32’s
Ah right that explains it, you are running at or at slightly higher revs than standard. I am running 31s with the 1.22 tc so overall gearing significantly higher...and this definitely effects things.

[manic]

1.2 Box
ZF Auto
32" Tyres
Standard 300tdi motor (IP tamper caps all in place)
Carrying the usual kit, bull bar, tow bar, tools etc = 2280kg

Can sit on 110kph (GPS) easily!

It might knock off a bit up steep inclines, but it can do 110kph regardless of wind and across most gradients. It can do 130kph on the flat no problem, and will push on to 140kph

My previous 300tdi auto was stock standard, same set up, smaller tyres and it struggled to go beyond 115kph. So it goes to show how the tune and health of the motor can make a big difference, especially when it is 20+ years on from factory fresh.

A 300tdi auto when new had no problem holding 120-130kph. I agree with Red90, the old motors that are struggling to do that now are either in a poor state of tune or have lost compression. With the high kms these motors have seen, its not surprising we get such varied reports on performance.

The speed limit in the UK is 120kph, if land rover had sold D1s that couldn't even hold the UK speed limit, it would have been killed in the reviews, and sales would have suffered big time.

Do all the easy stuff first, and start with a compression test. It would be a waste to load up on fuel/boost if you are already struggling due to poor compression.

Once satisfied that the motor is in good health and tuned to spec, look to up the main fuel delivery screw. Adjusting the boost compensator on an auto will not be as effective, the auto gets your revs up much faster than a manual. Increasing max fuel delivery will add power across the rev range. Just do it in small quarter turn increments till you are getting up to 690C on a hard push. A little tweak can make a BIG difference.

When you are hitting your EGT limit, look at a bigger intercooler, then turn up your fuel again. Hit the limit again and still want more, look at a bigger turbo for more PSI, turn up your fuel again.

Its easy to add fuel to these motors, you don't need a tune shop if you have EGT/Boost gauges and some tools.

My 200TDI defender is tuned up big time, 22psi VNT, performance head, double core intercooler, ceramic coated headers, 2.5" straight through exhaust, a good number of turns on the max fuel delivery screw. It has way more power than the 300tdi disco but it has a 1.2 ratio transfer case, 33" tyres, manual r380, its heavier and its an absolute brick. So it tops out at a similar speed to the 300tdi disco, and it might not beat the disco off the line if the gear changes are sloppy. So gear ratios, and weight are worth looking at too.

[Rick1970]

Did the exhaust on its own make much difference? Was thinking about changing mine.

[Fausto79]

Did the exhaust on its own make much difference? Was thinking about changing mine.

My D1 had standard exhaust when i got it. Was one of first jobs i did. 2 3/4 inch straight through. I have a silencer box in the middle protected by chassis and then goes straight out the back.

Not sure how blocked original system was but you could certainly feel difference after i picked it up. Turbo spooled much earlier and freely. You could actually hear it, where as before you struggled to. As far as acceleration and speed not sure it made a difference. Maybe had to adjust IP to suit but I didn’t.

In terms of smoothness, it was a different vehicle. At idle (if you had very good earplugs) you almost wouldn’t know it was running. Take off was just beautifully smooth. I still get that when i have a clear air filter. Which is why I’m looking at improving my intake with a better filter housing and better geometry.

[manic]

I did the exhaust at same time as turbo and snorkel delete. On its own I doubt the exhaust would have made much difference.

Unless the exhaust is rotting away, keep it, the 300tdi factory tubes are big enough for a fueled up tdi. If anything, free flow the center muffler. And then you might start looking at removing your snorkel. All for minimal gains.

Double core IC, and a twist on the max fuel screw will definitely make a noticable difference. If you can tweak the turbo wastegate for 16psi, even better. Some silicone boost hoses and good clamps for reliability. Job done. Try not to go overboard.... I know some of us cant resist!

[wllgbsn]

2600kgs give or take a person or two... thats what i got when i added it all up anyway, I’ll have to get it weighed sometime and see what I’m really at. Over summer I will attempt a compression test (is this a diy..able thing? Ill have to do some more reading i think). I contacted allisport and I’m on the waiting list for a double core IC but I suspect it will be a few months.

Starting probably next weekend ill be having a look at the fueling and just turn it up a notch ( i have a egt gauge). The compression was fine a few years ago, it got checked when its head was taken out and xrayed after head gasket failure (which was rectified) but it might be worth checking again. TBH it did drive a lot better without the roof rack (which adds about 30cm in height to the vehicle) which is causing pretty significant wind resistance. Similarly without any of the other mods (the heavy ones) it held its own a bit better. I suppose its just one of those things really. (Weight + greater surface resistance = slower or same speed + more fuel). I also do get significantly better fuel economy at around 95 km/h rather than 110 (which I can do on the flat (maybe 125 at full throttle and no headwind), just not on the uphills). :) Happy tuning everyone. I’ll let you know what i find once ive made some changes (or possibly tested a few things)

[damienb]

I've got a '96 300 Tdi factory Auto ES everything as factory (including tyres), nothing rebuilt, and it will manage 140 on the flat and cruise all day on 110-120 on the Bruce between Noosa and Brisbane. Maintains 110 easily on all the hills from memory.

I've detuned the pump slightly (idle setting) to reduce smoke on startup but otherwise nothing has been touched performance wise.

330,000 kms. Everything is original including exhaust, engine, gearbox, and suspension. Some bushes, belts, radiator (x2), head gasket (preventative), bearings, fuel pump gaskets etc, but no major replacements.

Damien

[AK83]

....

My manual D1 tdi has 245/75/16 and the speedo now reads about 94kmh when doing 100. Revs in 5th gear at that speed are about 2250. Before closer to 2500.

....

Mine's auto, on 255/70s and I get 2250 at 100k/h indicated(which is 100k/h actual too)
It may be 2260RPM as it's the thickness of the speedo needle above the 2250 line.

[edddo]

......... Adjusting the boost compensator on an auto will not be as effective, the auto gets your revs up much faster than a manual...... .

Never heard that before....maybe that is why I have always thought that the benefit I got from that adjustment was not quite enough. Have never upped the fuel delivery so will try that this weekend.

[manic]

Of the course the boost compensator plays its part but most people rotate the pin to the most agressive slope, wind in the smoke screw and thats it. This only slightly increases fuel across the pin stroke, and reduces its range of travel.

It will be trial and error based on egt and smoke out of the tail pipe.

On the auto I would try winding the smoke srew on top of compensator all the way out, so you have full restriction at idle and full range of the pin ahead of you. Max fuel screw will bring the preboost fuel back up. You will then have more fuel all the way through your pin stroke. Rotate pin to fine tune.

Watch the egts and tail pipe. Good luck.

[edddo]

Thanks..off topic....have you tried the RTT yet?

[manic]

Pm sent

[edddo]

Of the course the boost compensator plays its part but most people rotate the pin to the most agressive slope, wind in the smoke screw and thats it. This only slightly increases fuel across the pin stroke, and reduces its range of travel.

It will be trial and error based on egt and smoke out of the tail pipe.

On the auto I would try winding the smoke srew on top of compensator all the way out, so you have full restriction at idle and full range of the pin ahead of you. Max fuel screw will bring the preboost fuel back up. You will then have more fuel all the way through your pin stroke. Rotate pin to fine tune.

Watch the egts and tail pipe. Good luck.

Turned the fuel screw in a bit less than a quarter of a turn. Noticeable improvement in power / ability to hold speed in the 90 to 120 area. EGTs up to 630 on a long rise so don’t seem to have over done it. Will monitor it over the next week , will prob need to adjust smoke screw.

[DiscoMick]

Ours was turned a quarter of a turn. D1 300Tdi auto. Otherwise standard.
Cruised happily at 100 kmh, or 90 - 95 when towing.

[edddo]

1.2 Box
ZF Auto
32" Tyres
Standard 300tdi motor (IP tamper caps all in place)
Carrying the usual kit, bull bar, tow bar, tools etc = 2280kg

Can sit on 110kph (GPS) easily!

It might knock off a bit up steep inclines, but it can do 110kph regardless of wind and across most gradients. It can do 130kph on the flat no problem, and will push on to 140kph



Can you give me an idea of what your egt's are doing - lets say you are heading up that long rise on the Hume as you get close to Glenrowan from the south on the Hume hwy, it is 30 degrees ambient, you have a camping load on, and you hit the bottom of the rise at 110. You attempt to hold 110 all the way up - what would you expect your egts to do? Could you hold 110?

[manic]

I would like to know also. Everything under the hood is standard issue, it has not been tweaked at all, so there are no extra guages, I have no egt info. The only thing I have added is a low coolant alarm.

I dont remember speed at Glenrowan, so cant be that bad. Next time I head up that way with the disco I will take note. For long steep hills some days are better than others, 30+C saps some power for sure, on hot days it wants to be running light and given some sympathy up the hills otherwise it starts to get hot. Note to self: a new rad core for the summer.

What kind of egts, speed are you getting?

[edddo]

I think I could hold 110, just. EGTs would be over 650 ( and may max out ie 700+ so that I would back off) at the top under those conditions.

It is well and good to set the fueling so that it doesnt go too quickly to 700 but the real setting for sustainability is worked out over a hot summer with a mix of long haul highway and off roading in the heat.

I think mine is close to max but will monitor as the days get hotter.

[manic]

Smart moves.

In the tweaked defender I find egt is easily brought under control with right foot, even on very hot days. My egt alarm goes off at 690C, and I only need to back off the accelerator a fraction to hold it there. If I were to push on I could shoot it well over 700 im sure.

Offroad I have never come close to tripping the egt alarm. Mostly low range trundle, never racing.

[Fausto79]

just like to point out to the pump tweakers that if your pump has been re-conditioned by a reputable IP place that knows those Bosch pumps, it is likely to have already been tweaked off the shelf. i wasn't aware of this until a perth landrover specific mechanic told me this. so if you have it, check your car history to see if IP has been recond and if so see who did it. there's only a small handful of injection specialists in perth that the small handful of landrover specialists take the pumps to and all lof them have pre-set IP up-tune settings, in which case, be careful how much you play with it as you may get very close to top EGT. do not play with the pump unless you have EGT gauge.

obviously if you install a better IC or VNT etc. then you have more room to tweak pump but the above is FYI.

[Pub247]

You guys are all lightweights i had family and car loaded up away for 5 days camping on the way home so we would have been slightly lighter i was 3020kgs on the weighbridge. Last time I weighed myself coming back from a solo 7 day trip same weighbridge i was 2580kgs i have added a few things since then plus minus family and all associated crap that comes with them.

I can cruise at 100kph with family but the roof rack is stacked so having to punch such a large hole causes egt boost and water temp to be higher than i like. So i was mostly around 90-95kph mark depending on headwind. Solo i can sit on 110 easy and be comfortable with egt water and boost readings.

Note i have 265/75r16s with 3.54 and 1.2 transfer. Sit on maybe 2200ish at 100kph hard to tell with speedo being out

[edddo]

Of the course the boost compensator plays its part but most people rotate the pin to the most agressive slope, wind in the smoke screw and thats it. This only slightly increases fuel across the pin stroke, and reduces its range of travel.

It will be trial and error based on egt and smoke out of the tail pipe.

On the auto I would try winding the smoke srew on top of compensator all the way out, so you have full restriction at idle and full range of the pin ahead of you. Max fuel screw will bring the preboost fuel back up. You will then have more fuel all the way through your pin stroke. Rotate pin to fine tune.

Watch the egts and tail pipe. Good luck.

This has been great advice thanks Manic.

I am a bit baffled why I didnt come across this manual v auto distinction before...seems your thinking re the difference between auto and manual re the IP tweaking is almost your own.
I have done what you suggested and have rotated the fuel screw now a total of 180 degrees from where it was. EGTs are still quite ok.
There is a stop sign at an intersection that I go through on my way to work and it is half way down a hill so you cant see if a car is coming over the rise til the last second so I need to accelerate to get up to speed to avoid being an obstruction. There is a bridge maybe 500 metres away and before I was able to get to about 80-85 by then - now if I really booted it I could be doing 100. On top of that, the general drivability at 100-110 is significantly better. Smoke not an issue - I think I could go a little further on the fuel screw -my aftermarket intercooler is finally being utilised properly I think.
I have a new hybrid turbo and an exhaust manifold I bought last year - not much incentive now to bother fitting it. Might get to it one day.

(on the topic of great advice - I also came across the idea of putting the aircon on when on steep offroad descents as a way to improve engine braking ( which is otherwise not great in the auto tdi D1). This works so well, dont know why, but it really improves things quite signifiantly...this is a great forum).

[manic]

I will have to try out the AC button on hill descent, great idea.

Good to hear you have got the results you are after. If you do fit the hybrid turbo and up the boost there will probably be a few more adjustments to be made to the star wheel and boost pin. Keep an eye on my vnt+++ thread. Im not done tweaking just yet.