What is the right thermostat?

[dezinerdad]

I am thinking of installing a thermostat in my 03 C5 any thoughts out there in Corvette land. Should I use the 160 or the 180 degree? With or without a fan regulator?:confused

 

[johnl]

This sort of depends on whom you ask and what you are looking for.
The Certified guys will probably tell you the LS1 was designed to run at the higher temps and to leave the factory (195). Maybe a little lower (180) since higher temps helps with the emissions.
Every High Performance shop I’ve been to, and when talking to the tuners will tell you 160 with TB by-pass. Lower temps = more HP.
Personally I’ve had the 160 in since new, 145,000 mi. I just don’t like seeing it in the 2-teens and 220’s all during the summer months. I did the by-pass a while back, again for the cooler air flow.