10/7/05

Mike, My friend runs a drag car with a powerglide tranny in it. We were curious to know if tranny fluid temp effects E.T. It is a Hughes powerglide with a Coan 9 inch 5800 stall converter. If temp does effect E.T. what would be the optimum temp to run the fluid at. Any help you can give would be appreciated. Thanks, Joe Pawlak

Joe,

Transmission fluid temperature can affect performance in more ways than one. At higher temperatures the fluid gets thinner which causes the the torque converter to act looser, less efficient in extreme conditions. In very high horsepower cars we have seen fluid temperatures in the torque converter get so high that the fluid turns to vapor, and the engine will run away, but we are talking 600-700 degrees. Under normal conditions it's just about consistency, or consistently going to the starting line at the same temperature. They say that 195 degrees is the best engine temperature for power and I am sure that that is true for the transmission also, but I like to see it a little cooler than that before the run, again if you are running a class where consistency is important temperatures are the key.

The transmission fluid that you use is important also, regular transmission fluid is about 5 weight so it starts out thin and gets thinner!! At my shop Mike's Transmission we carry our own brand of ATF, we blend it ourselves. It is heavier than normal ATF. Originally we formulated our fluid to go along with our billet gears to give the fluid enough body to cling to the parts, and lube them better, we accomplished that and also received a bonus we found that our fluid would couple the torque converter better= lower slip %. So yes, Joe! There is a lot more to fluid than meets the eye!

Thanks,

Mike

Mike’s Transmission
Lancaster CA
(661) 723-0081

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