here is something i pulled from tuners

OK Here is my thought on manifold vs dp egt install.

I always install in the downpipe vs the exhaust manifold. Your basic Autometer EGT reads 1600 deg. When the probe is in your exhaust manifold you could get readings as high as that and not have to worry. If you listen to everybody and put it on the hottest cylinder then you will definately peg that needle.

Now what happens if something is wrong? Your EGT is pegged already so if your running 50deg hotter your not going to know. Well the needle will just move past 1600 right? Well yes and no. Talk to autometer about this one. They say that even approaching 1600 deg the gauge is not very accurate and definately past 1600 it is not. What may look like 50deg past 1600 ( or 1650deg) could very well be 1700 deg. But because you put your probe in the hottest spot you could find you'll never know.

What the acctual temperature is does not really matter. As long as your getting constent reading from the gauge is what matters. If you put it on your exhaust tip and it reads 200 deg all the time then fine. Just make sure you dont see 210deg cause that could mean problems. NOw obviously this is not ideal, but you get the idea.

What I always say to do is run it in the downpipe and always install your EGT on a car that is tuned perfectly so you know where it should sit on your car when it's properly running. If you want to know the difference between a manifold reading and behind the turbo I have generally found that you need to add 150deg to the reading if the probe is behind the turbo vs the manifold. Then your EGT will sit at ~1400 at WOT and if you run into a problem you have 200 deg of room left on the gauge to read it. It really doens't matter what the guage reads as long as it doesn't change when your tuning or driving around. If you get a different reading then you know there is a problem.

Those gauges are not even close to accurate so trying to put it on the hottest cyl for an accurate reading is nonsense, your only fooling yourself. Put it wherever you want but put it far enough away from the head that you have some type of room to go up on the guage so you can see if there is a problem. Having it pegged at 1600 deg under WOT becauese you put it 1 inch from the head doens't leave you a lot of guage left to see if there's a problem.

___________________________________________