Outer Limits 4x4 Board

hello I recently fitted a geuine turbo to my 4.2 diesel patrol and the exaust gas temp keeps on rising above 500 degrees celcius when I'm towing a load and I have back off every time it gets close 550 D/C I'm still running 2 1/4 exaust system with a normal muffler. If I put a 2 1/2 system with mandrel bends and no muffler on my patrol will this help keep the temperature down or do I need an intercooler it has been tuned properly so fuel air mixture is spot on thanks.

i think the exaust would help some but maybe not enough to completly fix your problem

maybe a inter cooler

i have herd of running a N/A deisel leaner to keep it cool cant say if the same thing works with a turbo though

cheers
elliot

Running it leaner will cut power, turbo requires more fuel, don't know how much for this engine or even mine for that matter but either way less fuel=less burn=less power.

No doubt that over fuelling will heat and possibly kill an engine though...

The idea of less fuel to cut engine temps would work but for what effect? Intercooler will help dramaticallycompared to a bigger exhaust though this will still aid it.

This is my knowledge anyway

Fuel screwed up to high but 550 isnt that bad though If it gets round the 6s then start to worry
Mine climbs to bout mid 5s when towing a big load but i just drive it to around 5psi on the gauge and not rev it to full boost and it comes back down.

Intercooler cools inlet temp and wont make exhaust temp drop so much.

From what you have posted it sounds like your "std muffler"is restricting flow causing exhaust gas to heat up in the turbine.

Larger diamiter exhaust will help for sure but again if muffler/s are not hiflow it doesnt matter how big your exhaust is you will have hi temp's.

Also dump pipe(pipe off the turbo housing) must/should be following the straightest possible path and be at least 2.5 inch's in diameter(based on t28/t3 turbo).

Have you had the fuel pump setup correctly by a proper Diesel place since fitting the turbo?

That would be my first stop having gone through all of this

Surely those sorts of temperatures can only be created by combustion in the exhaust pipe?

If so, that's diesel burning in the exhaust because it wasn't burnt in the cylinder. Either too much fuel injected, or it's not burning properly.

More/cooler air might help, but as hienuf said, won't make much difference.

I'd think pump or injectors, or both.

Good luck,

Scott

It has been tuned properly on a dyno and the pump and injectors were done 6 months ago so I try upgrading the exhaust system and see what happends. thanks for the input fella's.

when you do exaust go for a turbo flow muffler
basically less restrictive muffler

but dont go no mufflers probally will be to loude

was damb loude on a mates 2.4 td surf
imagine on yours

the reason i say this is in your first post you said you were considering a straight through no mufflers exaust

cheers
elliot

I run a no muffler exhaust system on my 2.8D hilux and its not loud at all, and i could tell the difference in quicker spool up when i took the muffler off.

My gu had temps reaching close to 700 even when I had the dump pipe and exhaust changed to 3 inch (no muffler).

Changed turbo and fitted intercooler. Twice as much power and has never passed the 500 mark.

Think the turbos are to restrictive

BIG ZETOR wrote:hello I recently fitted a geuine turbo to my 4.2 diesel patrol and the exaust gas temp keeps on rising above 500 degrees celcius when I'm towing a load and I have back off every time it gets close 550 D/C I'm still running 2 1/4 exaust system with a normal muffler. If I put a 2 1/2 system with mandrel bends and no muffler on my patrol will this help keep the temperature down or do I need an intercooler it has been tuned properly so fuel air mixture is spot on thanks.

go straight to a 3" system with no muffler, will lower your EGT, also have you a EGR? if so block the damn thing off

just wrap your exhaust in that white fabric and that will help keep the engine bay temps down. wrap around the dump and as much as the manifold as u can

hokey wrote:just wrap your exhaust in that white fabric and that will help keep the engine bay temps down. wrap around the dump and as much as the manifold as u can

Ummmm ... no, not quite the issue.

4xgold0 wrote: have you a EGR? if so block the damn thing off

Will an EGR be doing anything when you've got boost? In a petrol they're only supposed to recirculate at part throttle - not at idle, not at full throttle. If it's not recirculating during boost it shouldn't affect EGT.

Scott

NJ SWB wrote:

4xgold0 wrote: have you a EGR? if so block the damn thing off

Will an EGR be doing anything when you've got boost? In a petrol they're only supposed to recirculate at part throttle - not at idle, not at full throttle. If it's not recirculating during boost it shouldn't affect EGT.

Scott

im really not to sure Scott all i know is that when i blocked mine off, the EGT gauge reads about 80* cooler than before and thats just going to work and back,(highway about 50ks round trip)

4xgold0 wrote:

NJ SWB wrote:

4xgold0 wrote: have you a EGR? if so block the damn thing off

Will an EGR be doing anything when you've got boost? In a petrol they're only supposed to recirculate at part throttle - not at idle, not at full throttle. If it's not recirculating during boost it shouldn't affect EGT.

Scott

im really not to sure Scott all i know is that when i blocked mine off, the EGT gauge reads about 80* cooler than before and thats just going to work and back,(highway about 50ks round trip)

Sounds like it's worth doing, then.

I remember reading an artical about the factory turbo EGT running very high, one of the causes was due to the cast dump pipe running of the back of the turbo being very restrictive ( from memory 1 1/2 inch or 1 3/4) this didnt allow the exhaust gas to get away from the turbo quick enough., The fix was to remove it and fit a better breathing dump ( 2 1/2 inch + ) once this was done the fuel pump was then tuned to ensure the correct amount of fuel was being supplyed.

Regards

Daniels

What's a standard temp to run? I've got 3" mandrel at moment

The dump pipes I've seen are generally cast, is this to allow for the greater heat out of the turbo? If you were to make a custom dump pipe, say out of standard exhaust tubing, would it be able to take the heat directly post turbo though??

yes i think its cast
a it might be easier
b take the heat well

but i know you can get stainless dump pipes cant cost much to have one made up cus the amount of pipe needed wouldnt be that much

cheers
elliot

DanielS wrote:I remember reading an artical about the factory turbo EGT running very high, one of the causes was due to the cast dump pipe running of the back of the turbo being very restrictive ( from memory 1 1/2 inch or 1 3/4) this didnt allow the exhaust gas to get away from the turbo quick enough., The fix was to remove it and fit a better breathing dump ( 2 1/2 inch + ) once this was done the fuel pump was then tuned to ensure the correct amount of fuel was being supplyed.

Regards

Daniels

Exactly.....with turbo's one of the most important thing's is to expell the hot gases as fast as possible.

runnin4life wrote: i know you can get stainless dump pipes cant cost much to have one made up cus the amount of pipe needed wouldnt be that much

Stainless steels are generally a cr@p conductor of heat. If you're going to do this, choose your alloy well.

Scott

yer i spose they go stainless cus ut can take the heat with out carpping itself i spose there is a speical alloy they use for it

cus u see the polished stainless dump pipes in the ricer mags well when i used to read them i did

cheers
elliot

runnin4life wrote:yer i spose they go stainless cus ut can take the heat with out carpping itself i spose there is a speical alloy they use for it

cus u see the polished stainless dump pipes in the ricer mags well when i used to read them i did

cheers
elliot

Sometimes the polished look is actually ceramic coating which helps keep the heat in the pipes not the engine bay.

runnin4life wrote:u see the polished stainless dump pipes in the ricer mags well when i used to read them i did

I'd guess the average 2 litre mall-cruizin ricer with its polished dump pipes doesn't get that hot - certainly not as hot as a 4.2 litre Patrol or 'Cruiser pulling two and a half tonnes of boat/caravan/horse float up a long hill on a highway.

And a polished stainless pipe won't radiate heat as well as a dirty cast pipe.

I still reckon it's pumping too much fuel.

Scott

A boost compensator will also help with any over/under fuelling problems...

I would say start with the easy and most sensible things, if you have a standard exhaust replace this with a more free flowing one which will not restrict the turbo, try a 3/3.5" mandrel bent stainless dump amd depending one your money situation chose the rest of your exhaust from there. I think this will solve your problem but failing that move back along the line as to what standard component will be causing your engine to work overly hard.

BIG ZETOR wrote:... it has been tuned properly so fuel air mixture is spot on...

Petrol engines have a narrow range of fuel to air mixture ratio approx 1:14. As the throttle is opened allowing more air to enter the cylinders, the fuel is metered to keep the fuel air ratio reasonably constant. A petrol engine will run hot if the mixture is too lean.

Diesel is a completely different story. No tuner can claim that the fuel air mixture is spot on.

A diesel does not have a throttle. The amount of fuel is controlled by the govenor in the injection pump (or computer in modern engines) and the fuel to air ratio is not constant, but varies from extreemely lean at idle to so rich that there is not enough air to completely burn the fuel.

Incomplete combustion causes black smoke and elevated exhaust gas temperatures. A diesel engine likes to run lean.

Inject more fuel to produce more power, but this creates heat!

As others have stated, reduce the fueling to reduce the exhaust gas temps. This will reduce the fuel to air ratio.

Increasing the amount of air will help to reduce temperatures. Intercoolers, removing restriction in the inlet side and exhaust side will all help.

When climbing a grade with a load, the worst thing is to allow the engine to lug hard. It is better to change down a gear and get the engine revs up.

can you buy a 2 1/2 to 3 inch dump for this turbo anywhere or would you have to make one yourself it is a factory water cooled one.