ok ive got my probe to my egt guage a few inches down from the back of my turbo. What is the temp difference in pre and post turbo? Whats acceptable and whats not? thanks

 

I think there is a 300 degree dif between pre and post turbo. Anything over 1350 for a an extended period of time is bad. I occasionally peg my 1600 degree pyro

 

If you put it post turbo you are pretty much guessing at the exhaust temps. Some will disagree, but most guys go pre-turbo

 

Pre Turbo is the only way to go IMO

 

Yup...pre-turbo is the only way.....unless you want to be doing math while your driving/racing.

You can use approx. 10*F for every pound of boost (added to your pryo reading) ...once you reach approx 25'ish PSI you'll need to up the ratio to about 11-12*F per pound, the higher the boost numbers the more that value goes ascque....that's how it worked out on my first gen with the probe about 2 1/2" downstream from the turo outlet when compared to 1 1/2" prior to turbo flange in the manifold.

pb...

 

I'ver personally seen over 550° difference between pre and post during WOT transients.

If you are using a pryo to gauge safe EGTs for seriously overfueled engine, PRE is your ONLY option.

Post turbo is only good for large, non-wg turbos that don't see high transients.

For example, a 160hp 1st gen with a 21 housing is fine with a post-turbo pyro probe.

A 400hp 2nd gen with a 12 housing NEEDS a pre-turbo probe.

Can everyone see the difference??

 

Post turbo can vary by as little as 300 degrees at idle, to over 550 degrees at WOT.

As long as you are sure you can always do the math.
Preturbo is a much better option, no math required.


phox

 

good gosh, i didtn think that there was that much difference. ah well, i aint in that much trouble. Thanks guys

 

Yeah, I put a pipe plug in my Post Turbo tap and moved the probe to the manifold...I saw more than 300 deg difference...

 

I will second Saxet
Put a plug in and relocate to pre.

 

nah ill just stick with my post and do a little math.