i have a greddy peak/hold egt gauge. when i am driving normally it stays around 400*c. it bumps up to 600 to just under 700 tops from what ive seen under wot. is this normal for probe placment just after 02 housing? i know its ganna be not as hot there, but it seems way lower than normal, and im wondering if the gauge is working correctly.

 

if i'm not mistaken you should place the probe 2-3 inches from cylinder head. having it so far down the pipe like you do will give inaccurate readings.

 

I am not sure you will find much information here that will be useful in comparing temps due your your probe placement. My probe is placed in the number two runner of the exhaust manifold about 2" from the exhaust port (see pic). I would imagine that temps would naturally be much higher there. Your normal driving temp of 400*C (752*F) is much lower than the 1200*F (648*C) my gauge reads under the same circumstances. While this doesn't answer your question, it does confirm the significant difference in exhaust temps between the two probe locations. Do a search for "EGT readings" and you will find more information.

 

yes, i understand the probe placement issues. i put mine in the downpipe because the pipe i bought had a bung already installed. regardless if they are lower, the readings should be accurate still... but lower of course. what is the edge of normal to high range for in the dp? ive heard 100-200 degrees lower than in the manifold. i never hit near 700* so i guess its ok.

 

What information do you hope to get from the EGT? The temperature drops a lot going through the turbine and how much it drops depends, among other things, on the exhaust gas flow rate and backpressure at the outlet, both highly variable. You may get accurate temperature readings but there really isn't much useful information you can get with the probe located after the turbine.

Dave

 

I have ran an EGT in the manifold (Runner #2) then when I went to a bigger turbo and now run my probe in the O2 Housing right before the downpipe flange and the results I show seem to give me about a 200-250 degree difference. I hope this helps some of you.

For example when crusing with the probe in the manifold I would go from 1350-1400 degrees at 70mph at average with a constant pull. Now I see 1100-1200 degrees in the O2 housing, I will be sure to check my measurements again this weekend and post any differences but this should give you a general idea. If you are in the downpipe I would say you would loose another 50-100 degrees.