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Trans cooler size air only

Posted: Fri Dec 11, 2015 8:42 pm
How large of a trans cooler should you run if your radiator doesn't have anything for the trans? TH350 street/strip

Re: Trans cooler size air only

Posted: Fri Dec 25, 2015 4:07 am
by Greenlight
A TH350 may lose about 7 HP due to slippage and friction during normal driving and 30 HP or so during WOT. These losses are what heats up the fluid.

It will be hard to find a standard cooler that is efficient enough to cool the oil as a result of a 30 HP loss.

The basic equation is:

HP x 746 Watts/HP x 3.41 BTU/hr/Watts = required cooler heat transfer rate in units of BTU/hr


7 HP x 746 x 3.41 = 17,807 BTU/hr

If you had a cooler with this heat transfer rate, the transmission fluid temperature would never increase.

Many cooler manufacturers provide the nominal heat transfer rate of different sized coolers.

Try and keep the fluid temperature below 190F or so (180 F preferred).

Re: Trans cooler size air only

Posted: Sun Jan 03, 2016 2:27 am
Thx for the info decided to use cooler with fan.