EGT questions

[mosk]

I've been trying to find some decent info on acceptable EGT temps and probe placement, and I can't seem to get a straight answer. Maybe someone here can help.

First, I should say that I don't have a Buick. What I do have is a F.A.S.T.-controlled, turbo Toyota 4x4. It's a street driven, 4 cyl. truck with a T3/T04E ball bearing turbo, intercooler, forged pistons, and 47lb. injectors.

What is a typical "safe" operating range for EGT's? I have a WBO2 on the F.A.S.T., so I'm not really interested in using EGT as a tuning aid, nor am I trying to squeeze every last bit of power from the motor. What I do want is to make as much *safe* power as possible on a motor I hope to drive on the streeet for 60k miles or more. I've been told that, to protect the turbo, I shouldn't let EGTs rise above 1300°, as measured on a probe in the collector (turbine inlet temp). This is because the T3 turbine is fairly small and repeated exposure to temps above 1300° will lead to premature failure on a street vehicle. Does this make sense to anyone here? What sort of temps do you see, and where do you have your EGT probes mounted? Is just before the turbo correct, or closer to the cylinder head in an exhaust runner? Do you use turbine inlet temp to protect the turbo, or EGT to safeguard the pistons, or both?

Thanks for your time and whatever info you can share.

Jeff

 

[straycat990]

with the probe located 2 inches before turbine inlet I have seen as much as 1675 when the engine was leaning out, but normal egt is between 1500 and 1550. those temps are at the end of the quarter mile. the engine seems to run its best at those egt temps. O2s were right were they should be too in the high .700s.

 

[NEARING]

1680-1715 all the time on good gas and no alky. but I don't run much timing up top as I am a puss .

about 1550 on pmp gas and alky.

I guess mine is about 2 inches from the inlet too.

I run a digital egt meter.

I would think your max allowable temp would depend on your combo,make, ect.

 

[REDS HOT AIR]

If you melt the turbine wheel its too high

 

[BoostKillsStres]

Originally posted by REDS HOT AIR
If you melt the turbine wheel its too high

HEHEHE got a good laugh out that RED Mine seems to like the 1550-1650 zone.

And remember different engines like different egt's so ours may not be what you should shoot for as I think most of the SBC guys shoot quite a bit lower.....or maybe they're just scurred

 

[mosk]

Thanks!

Thanks a lot for sharing your results. It's helpful to know what sort of temps others are seeing. I plan on moving my probe to a few inches after the cylinder head, so hopefully my data will be more useful.

Thanks,

Jeff