Howdy everyone, I am sure I will be stirring the pot with a few of these questions. First, I live in the pacific NW, about 60 miles north of Seattle. The temperatures around here have been in the 70-80’s in the afternoon and 50-60 in the late evening/morning. I have a 98 C5, mostly stock, my coolant and oil temp’s are the same both before and after all mods. It has the red coolant in it.


At idle with a 60-70 IAT, I was hitting 235+ ECT’s and EOT at 220+. After I started driving, the ECT’s would come down, but not the EOT. I reprogrammed the fans to come on earlier, and now I am getting ECT’s around 205-210. Basically, my ECT’s are running at the temps I have the fans set to come on, and my EOT’s heat up and almost never come down. I have blown out my radiator etc. And I do not use my A/C.

So here are my questions,

What kind of ECT’s and EOT’s are considered “normal” and what is best for performance, and why?
What ECT’s and EOT’s are others running at (at what IAT’s or outside temps)?
What coolant is better to use, the green or the red, and why? J
What is the best temp thermostat to run and why?
Would an oil cooler be beneficial?

I am sure I will have more questions later. Hopefully we can use some to make a large F.A.Q.?

Thanks in advance,
Bob

P.S. J
Oh, and just incase someone asks,
EOT= Engine Oil Temp
ECT= Engine Coolant Tem
IAT= Intake Air Temp
I have been using EFIlive to log and track my data and LS1edit to program.

 

I was driving two days ago in 106 ambient air temp. and my car was
running about 187 to 192 without AC, w/AC the temps were up to 197 to 200. I was at the Dragsrip that afternoon and my car never exceeded 190. The oil temps got a bit hotter, but not by very much.

Have your fans reset to a lower temp.