Turbo Diesel Tunning and fault finding

[WelchyGQ]

Trying to tune my Patrol with after market turbo. Running 10PSI.

While towing my camper (1.5t) the pyro can nearly nudge 600 on steap hills... is this causing damage in short durations?

what can i do to reduce EGT Temp? Intercooler? or fuel or what?

Anyone know where i can get a bolt on intercooler kit for a good price?

Also i noticed the gearbox is getting a fair bit hotter than it does without the trailer. I changed the oil and no good. Is this normally for it to heat up signifigantly with that sort of towing load?

sorry if these are novice questions but i know nothing about turbos and the gearbox thing hasnt happened to me before.

Cheers,

Welchy

[ISUZUROVER]

Where is your EGT? Pre or post turbo?

600 pre turbo is fine. 600 post turbo is a bit high.

[WelchyGQ]

nah it is about 2" after the turbo in the dump pipe

[ISUZUROVER]

nah it is about 2" after the turbo in the dump pipe

Ahh. Then your pre turbo figures are anywhere from 750 to 850+. A bit too high. 500 max is probably a good figure to aim for.

Intercooling or turning down the fuelling will help.

[WelchyGQ]

so if i wind the fuel back a bit wont that make it run lean?

[ISUZUROVER]

so if i wind the fuel back a bit wont that make it run lean?

You are thinking petrol. Diesels always run "lean"

Leaning the fuel on a diesel decreases EGTs.

[WelchyGQ]

so obviously you would come to a point when it was "lean" enough to effect performance?

[ISUZUROVER]

so obviously you would come to a point when it was "lean" enough to effect performance?

Reducing the fuelling will affect performance, but that is a necessary tradeoff if you want the engine to last.

If you fit an intercooler you should be able to turn it back up then.

[gazza 1]

Gooday, i thought i would put in my 2 c. I recently had my wagon dyno tuned at a Nissan recommended diesel mechanic in Warragul in Vic. My egt were around 600 degrees at 115 kls , unloaded (not towing) and was told this is around the norm for my car. This was post turbo.I dont know if there is a ratio for loaded speeds, i assume there are too many variables, weight ,shape ,axles, etc. Can anyone confirm from any workshop manual or data what are the acceptable or standard temps apply to our cars. By the way when i have the gas turned on the temps go to around 630 at 115kls, but was told this was fine.
Regards Gazza

[its aford not a nissan]

3 things you can do to drop egts
1/ up the boost a bit to say 14 or so psi
2/ intercool it
3/ and one which still confuses me as to why ?? fit an electric lift pump in the fuel line between the tank and first filter

all these things lowered egts on my car

[KiwiBacon]

Gooday, i thought i would put in my 2 c. I recently had my wagon dyno tuned at a Nissan recommended diesel mechanic in Warragul in Vic. My egt were around 600 degrees at 115 kls , unloaded (not towing) and was told this is around the norm for my car. This was post turbo.I dont know if there is a ratio for loaded speeds, i assume there are too many variables, weight ,shape ,axles, etc. Can anyone confirm from any workshop manual or data what are the acceptable or standard temps apply to our cars. By the way when i have the gas turned on the temps go to around 630 at 115kls, but was told this was fine.
Regards Gazza

Shift the probe and tell us what it reads.
I'm wondering if the tuner doesn't know the difference between the two thermocouple locations. 600-630 is fine pre-turbo.

[Dzltec]

Our limit is 550c at the dump pipe but as close to the turbo outlet flange as possible.

Yes diesels run lean or on excess air, it will not cause a mechanical problem. There is no temp limit in any workshop manual made for cars or 4wds that I know of.

Load will alter how quickly exhaust temps rise. At the end of the day, don't go over 550c at any time.

As said, more air via added boost (but there are limits ) or a better flowing turbo, a free flow exhaust system, making sure valve clearances are correct and the air filter is not blocked all help. Reducing fuel delivery amounts will help, but will also lower power outputs. An intercooler will also help.

If the tuning has not been set correctly, it may still get over 550c. Thats why it is highly recommended to fit and exhaust temp guage. It can then be controlled via your right foot.


Andy

[WelchyGQ]

http://www.bigo4x4.com.au/default.asp?page=custom

What does everyone think of this kit?

Cheers,

Welchy

[dumbdunce]

3/ and one which still confuses me as to why ?? fit an electric lift pump in the fuel line between the tank and first filter

if we are taking VE (rotary/distributor) injection pump with considerable km (anything upwards from 150,000km), it's because the "first stage" of the mechanical fuel pump is a vane type lift pump which keeps the pump body full of fuel, and also generates hydraulic pressure to advance injection timing. as the lift pump loses efficiency, timing becomes a little bit retarded especially higher in the rpm range. if the timing is retarded, fuel is still afterburning when the exhaust valve opens, so EGT's are high without your engine developing any power from the extra heat.

fitting an electric pump (edit!) upstream of the pump assists the lift pump and re-advances the timing so the burning happens in the combustion chamber where it should.

[ISUZUROVER]

There is no temp limit in any workshop manual made for cars or 4wds that I know of.

The manual for the ISUZU 4BD1T (fitted to 6x6 land rovers from 1985-1990) specifies a max EGT (pre turbo) of 750oC.




The relationship (or lack thereof) between pre and post turbo EGT. Measured by thermoguard instruments.

[its aford not a nissan]

3/ and one which still confuses me as to why ?? fit an electric lift pump in the fuel line between the tank and first filter

if we are taking VE (rotary/distributor) injection pump with considerable km (anything upwards from 150,000km), it's because the "first stage" of the mechanical fuel pump is a vane type lift pump which keeps the pump body full of fuel, and also generates hydraulic pressure to advance injection timing. as the lift pump loses efficiency, timing becomes a little bit retarded especially higher in the rpm range. if the timing is retarded, fuel is still afterburning when the exhaust valve opens, so EGT's are high without your engine developing any power from the extra heat.

fitting an electric pump (edit!) upstream of the pump assists the lift pump and re-advances the timing so the burning happens in the combustion chamber where it should.

well your the first person to have an explanation for me , i also didnt realise that the pump advanced itself through the rev range , i always thought it was fixed and only the newer gu pumps had an electric advance system fitted

[philhod]

I just recently had my Patrol dyno tuned by Denco in Wagga. I found that it was hitting 550 to often for my liking and I was continually backing off the throttle to lower the temps. Towing is much worse and because we are towing a loaded trailer for a Postie Bike Challenge through the Flinders Rangers and up to Lake Ayre I would feel more comfortable if the temps were lower.

After telling Denco what it was doing his suggestion was to rip the gauge out because it sounded like I was worrying about it too much and advised me that even standard they run over 550 turbo . Obviously not his motor.

$400 later and it will still hit 600 if your not careful.

I would like to here from anyone who has a EGT gauge fitted to a standard 4.2 to see how hot they do actually get.

[zagan]

A properly sized AFR guage would be handy to have as that will let you know if your running too lean or rich.

So if your EGTs are high and the AFR is rich then you could try lowering the fuel a bit and see what happens after that.

[Chucky]

3/ and one which still confuses me as to why ?? fit an electric lift pump in the fuel line between the tank and first filter

if we are taking VE (rotary/distributor) injection pump with considerable km (anything upwards from 150,000km), it's because the "first stage" of the mechanical fuel pump is a vane type lift pump which keeps the pump body full of fuel, and also generates hydraulic pressure to advance injection timing. as the lift pump loses efficiency, timing becomes a little bit retarded especially higher in the rpm range. if the timing is retarded, fuel is still afterburning when the exhaust valve opens, so EGT's are high without your engine developing any power from the extra heat.

fitting an electric pump (edit!) upstream of the pump assists the lift pump and re-advances the timing so the burning happens in the combustion chamber where it should.

Dumbdunce is a man to listen to.

My 80 with 1hz T/I at 16psi would only get to about 500' at full noise with 1200kg camper on the back going up the T'bar range.
Personally anything over 550' is going to end in tears.

just to compare thou, my 60 series did it yesterday, with 6.5 chev at the same speeds at only 175' etg

[KiwiBacon]

just to compare thou, my 60 series did it yesterday, with 6.5 chev at the same speeds at only 175' etg

If you have EGT readings that low, then you've got issues with your measurement gear.

180C is a warm idle.

[Dzltec]

3/ and one which still confuses me as to why ?? fit an electric lift pump in the fuel line between the tank and first filter

if we are taking VE (rotary/distributor) injection pump with considerable km (anything upwards from 150,000km), it's because the "first stage" of the mechanical fuel pump is a vane type lift pump which keeps the pump body full of fuel, and also generates hydraulic pressure to advance injection timing. as the lift pump loses efficiency, timing becomes a little bit retarded especially higher in the rpm range. if the timing is retarded, fuel is still afterburning when the exhaust valve opens, so EGT's are high without your engine developing any power from the extra heat.

fitting an electric pump (edit!) upstream of the pump assists the lift pump and re-advances the timing so the burning happens in the combustion chamber where it should.

I couldn't have said better myself. We are now checking this pressure called transfer pressure on the vehicle when we dyno them. It is adjustable, but if things are worn too much, it won't get back to original specs. It does make quite a bit of difference to a final tune.

Isuzu rover: good find, it looks like that at 750 pre, you are making 550 post. It substantiates what has been said quite a lot. And shows the importance of using an EGT guage.


Andy

[stormpatrol]

I just recently had my Patrol dyno tuned by Denco in Wagga. I found that it was hitting 550 to often for my liking and I was continually backing off the throttle to lower the temps. Towing is much worse and because we are towing a loaded trailer for a Postie Bike Challenge through the Flinders Rangers and up to Lake Ayre I would feel more comfortable if the temps were lower.

After telling Denco what it was doing his suggestion was to rip the gauge out because it sounded like I was worrying about it too much and advised me that even standard they run over 550 turbo . Obviously not his motor.

$400 later and it will still hit 600 if your not careful.

I would like to here from anyone who has a EGT gauge fitted to a standard 4.2 to see how hot they do actually get.

HI BLOKE got a turboglide kit fitted sum time ago runs a bb garret at 9.5 lbs highest egts we have had is round 500 uphill at 110ks and no smoke at all very happy with the kit