[70GS455]

Originally Posted by LKLusza

LOL, You are so right abut that!

I think I finally got a reasonable handle on the heat thing. First off - thank you for questioning the vacuum advance setting on my Progression Ignition Bluetooth dizzy. Investigating it, I found that the default settings have the Vacuum adv begin to come in at about 6inHg. That's fine. But it added it slowly to be all in by 23 inHg! My engine idles at about 14-15 inHg. This means that my engine was only ever seeing less than half of the 16 degrees I had specified. Not good. So, I created a new tune with the same numbers, but that has the vac start at 6inHg and is all in by 13inHg, which is 1 to 2inHg less than my idle vacuum. The idle picked up and there is no "dithering" in the idle speed either. And the off-idle/part-throttle response improved tremendously. It was like a different engine!

Now the engine was seeing all the timing it was supposed to at idle, I also changed my coolant mix to 25% antifreeze/75% water with an appropriate amount of Redline's Waterwetter additive. Given that my car is a three season vehicle that is stored in a climate controlled garage, I think I can get away with that. There is enough antifreeze to maintain corrosion protection too.

My final test was to run exhaust tubes from the car to outside the garage. I then idled the car with the AC on and with the garage doors down as far as possible. Air temps inside the garage got sweaty real quick, but after about a half hour, the car never got above 218 degrees.

With the performance increase from the timing adjustment and the waterwetter/coolant change, I am pleased enough to call this a win and let it go - for now

Thanks to everyone who contributed to the discussion. Your input made me check and verify things that I didn't think were related until I looked. Now it's time for a cold one!

With the 2797 you'll want to adjust the fan engage temperature