i have a new thermostat in, got a stock fan with toggle switch, and put in water wetter. i noticed the biggest difference when i put the water wetter in. i flushed the whole system out, did water + water wetter mix only, and set the idle at 3500. let it idle at that rpm for 15 min. and it never got above 200 degrees.

 

i took mine out not long after i got my bike and havent had any trouble since

 

Ask any drag or circle track racer and they will tell you the same.

Not for GM.

 

maybe if i start drag racing or start flat trackin the 636 i will put mine back in but it seems to work fine for me without it