UrSoccer_mobileĀ®

got these two choices at my FLAPS..

Rich L.

Stock is the 87 degree thermostat and that's better for a street car because it keeps things in the right temp range. On my track car I run the 80 degree where the cooling system is struggling to keep up.

This is based on the recomendation of my engine builder who's got lots of street and track experience.

Rich

N'CTRL

I went with the 87. I still have it sitting here though, because I couldn't get the old one out, even when trying to pry at it a little with a screw driver.

UrSoccer_mobileĀ®

thank you Rich.

quattro20v

87

quattro20v

strap and heave-ho.

kday

Assuming that either the 80 or 87 thermostat will be open under track conditions, does it really matter?

EvanUrS4

If it opens 7 degrees earlier then it has that much more time to start running as the car gets hot.

Rich L.

When the engine is running under long periods of sustained boost, like a 20+ minute track session, the limitation in cooling ends up being heat transfer between the cylinders and the cooling passages. So having the water enter the passages at 80C rather than 87C gets more heat out of the cylinders themselves. This assumes you have a radiator that is sufficient to cool the water to 80C under such conditions.

At cruise or idle, having the water enter at 80C is excessive and over cools the cylinders. This makes for generally poor or inefficient running where you are most of the time on the street.

Rich

kday

I know mine can't under load -- it can't even cool it to 87C on the track or even in traffic during the summer.

I have been thinking that I may need a new radiator though...