Hey, I am trying to better understand how the temp on a EGT sensor reflects how the car is running. Now I know that when the car is running to lean it will run to hot and of course the temp will be low with the car runnign rich. With that said how am I supppose to know what right temperature is(what approx is the right temp?)? I will hook the gauge up before I put the turbo on and U will get a good baseline I suppose. But with turbo won't the car always run hotter? Or will my goal be to keep the exhaust temp where it was with the car NA? So many questions about all this stuff, hehe, thanks for any help

 

You shouldn't actually get a higher temperature just driving around on a normal basis. At idle, you will be between 6-800 degrees F. Cruising at 55mph+ you will be around 1000-1200 F depending on the speed. Running the 1/4 or at high speed will net you around 1300 NA, and on boost you should see no more than 1450 (in that area) If you start going over 1500, you are getting a bit lean... Hope this helps.

 

Yes install it before the turbo and get a good base line. That is what I did when I first went with the nitrous.

AFR is one factor for EGT's. From my experiance 800c is a safe spot to keep the car out of detonation on a 4th gen with no timing retard. My car now runs ~740-760c and I am tuned at ~12.5:1 AFR. For brief sprints 850c MAX is ok but not for extended periods of time. When running juicy boost I have seen 840c at the 1/4 mile trap with no damage.

Detonation will cause high EGT's also, the way I used the EGT gauge before I got the J&S I tried to keep the EGT's close to what they were when I was NA. I never had a problem with detonation by doing this.

You need to put the EGT gauge on and drive NA for a while to really see what it looks like.

Power output has little to do with EGT's. AFR, detonation and peak cylinder pressures are the factors involved.

 

Thanks for the great replies guys!



One question though, MardiGras, your number are in celcius right? And Mtrai yours where in F right? Thanks

 

yes

 

yes. Do a search for 'temperature conversion' on the internet and you can easily find conversion calculators that change C to F and vice versa.

 

This should be a sticky or faq for future reference. We could also use a fuel pressure gauge reading faq. I searched and there's too much information to sift through.

 

Mardi and Mtrai...where are your probes located?

 

This is a somewhat personal question.


Mine is on the y-pipe near the flange by the O2 sensor. I was wondering if this was going to cause problems because any exhaust leak near an O2 sensor will be detected by the sensor and then the ECU thinks the engine is running lean and will try to compensate. But no problems so far.

 

Right on - that's EXACTLY how mine reads. (f)

700-800 or so at idle
1000-1200 at 55-70mph (cruising)
1450 at full boost.

I'm tuned actually a little lean - 12.5:1 throughout the powerband, peaking at 13.0:1 at the very end of the range (6800 RPM)

IanS

 

*C to *F = (*C x 1.8) + 32