What EGT's are you running and consider safe?

hello

just curious what EGT's you running and is consider safe

i have NA v8 car that is turbocharged i have enlarged the ring cap with have forged rods.

have EGT's on alle the cyl so can monitor everyting .

personally i think i can run safe 900c on my streetcar .

im doing some street tuning with the car with a new turbo setup running om pumpgas running 0.8bar boost now

and seeing 1 cyl having a higher egt then the rest 1 is 925c the rest is around 860c .

i have to check this cyl or do a fuel trim on it check the ignition coil why only this cyl.

but im curious if you monitor the egt where you aim for ?

regards, Johan

It used to be that Garrett turbo cartridge separators were good up to 820C so it wouldn't make any sense to go above that temperature. Nowadays they use stronger materials as entire turbo industry made significant improvement in technology. But as a rule of thumb I still try not to go above 850C on a long run.

No specific suggestion, but different turbo's and turbine materials will have different max' recommendations. I'd suggest checking with the turbo' manufacturer's recommendation.

Depending where you're taking them from, and the specific design of the manifold, the actual temp' at the turbine may be a bit below at the port.

For the variation in EGTs, first thing I'd be doing would be to check the injectors are at 100% flow, with a clean and even discharge. Depending on the intake and exhaust manifolds you may also find there's a difference in airflow, which may mean trimming the injectors' fuelling. If that's the case, you may also be able to tweek each cylinder's ignition timing, but that's a lot of messing around.

@georg1970 yes i think 850c my other cyl temps are all around 830-860c

@gord my injectors are new , like 700km driven on them and is a flow test matched set. so should be good. if i look to the other logs i have also from lower load area's the EGT on cyl 6 is not the highest the longer im going on the throttle the difference is getting bigger but tops off also . i will also swap it around with another cyl and see if the temp difference is moving also with it . i can do the same with the injector offcourse

@georg1970 @gord. you suggest that the turbo can only handle a certain amount of temp but there is also the piston and valve's that can fail. or is the turbo an earlier part that will fail in your opinion when see highe EGT's

Combustion chamber temperature and egt are not the same thing. I've attached two pictures of the same cylinder to demonstrate it how they depend on ignition timing. First picture is with ignition timing of 20 degrees before TDC - pressure in combustion chamber is high (so is temperature according to ideal gas law) but exhaust gases temperature isn't that high. Second picture is the other way around it - ignition timing is 20 degrees after TDC so the pressure inside combustion chamber isn't high (so is the temperature) comparing to first picture but egt is very high (which of course isn't good for exhaust valves but doesn't matter for pistons since they are far away down the bore when it happens).

@georg1970 thanks !! that makes sense.

i had a knock event and lowered the ignition with 2 degrees got no knock anymore but raised the EGT with 50-60c

before that the cyl 6 was also 50c higher then the others

so makes then. thanks