High IAT2 temps and KR


Well-Known Member
My 2.8 pulley'd SC is also regularly in the 130's, but that's what it ran in the cobalt also, which had a ZZP HE. Even after I added dual-pass and intake spacer when building the goblin. Never have any KR or noticed any issues. This is with the HE fan, no ducts.


Goblin Guru
Some had added a pusher fan on the EC rad with the naca duct. This should get you good flow at all times.


Well-Known Member
How long had you been cruising around to get 134 degrees? To me cruising would be no boost and therefore no real heat generated by boost.
I'd say maybe 5 to 10 minutes before I hit the 130+ temps. It seemed to track almost perfectly with coolant temperature, just about 50 degrees lower, which lead to my theory that it was getting heat from the radiator. I was never in boost at all. Vacuum pretty much the whole time.

I've seen numbers of 150 thrown out as starting to be a point of concern, but never anything to back that up. Are you doing a log when you saw these temps and are you monitoring knock?
No log, just me eye-balling my aeroforce gauge. Same thing for knock...the gauge was showing about 3 deg KR, and it didn't seem to change as the temperatures did. I'm not sure how big the sample size needs to be before KR updates.


Well-Known Member
The intake manifold puts quite a bit of heat into the coolant loop. I'm surprised how warm mine stays even on cooler days.

I haven't watched IATs real close, but I have only seen 1 degree of KR once. It's tuned pretty conservatively since it's an LAP.