[Jeff Chambers]

You really need to baseline the temperatures with a known A/F ratio. Go to the dyno and tune the car with the wideband O2 meter. Then make a few full passes with the car in that configuration (hopefully in similar weather conditions) to get a baseline EGT. Don't try to establish your EGT while you're on the chassis dyno. The EGT is too slow responding to get a full EGT reading during a six-second dyno pull.

I usually try to set my baseline on the engine dyno since you can hold the motor under load long enough to let the EGT fully respond. You also get immediate EGT/HP correlation with the engine dyno too. I suppose you could do the same on the chassis dyno if you're dyno operator is willing to hold your car at 6000+rpm for a few seconds rather than just passing through it.

BTW: My best HP/ET/MPH seem to be with an EGT around 1460F, but this doesn't mean squat for your combination/EGT placement/etc. There are a ton of variables that will affect the EGT temperature.