Transaxle oil cooler pumps Options

[pcar916]

How many of you are using gear pumps instead of diaphragm types and what filter element (micron) sizes are you using?

[john rogers]

For the temps question, I found with my trans temp gauge that until temps got to about 140 to 150 the trans seemed to be sluggish but then it was setup with tight clearances and ran a limited slip. Once temps got to over 275 or so the shifting got bulky and you had to shift slowly and very deliberate. This only happened at the street circuit races in Mexico where the straights were short and there was not enough time for some cooling and that is why I added an axial fan in the ducting line with a water mister from JC Whitney and Co that was actually meant to be an add on windshield washer reservoir and pump. The pump went to a garden mister and was switched with the fan and would drop trans temps by about 20 degrees when running which helped. The little bit of water lasted about 15 minutes which was sufficient for a sprint race. I was too old to do any of those enduros!!! The type of limited slip did not seem to make a difference as I used both a Guard and a "Q" which are different designs I think? I also had a pretty good shift setup with one of James' first Rennshifts and an aerospace coupler in place of the middle flex coupler.

It is the high RPM that gets the parts, especially the racing with high RPM motors and the revving with each shift, especially with engines that routinely rev to 8,000 RPM like my 2L six did. When I moved to a 2.8L six later on, the temps dropped slightly but only a little as the engine rarely went over 7,000 RPM. The HSR, VARA, HSR-West and other Porsche 2L class cars that bilders like Wayne Baker, Frank Beck and Jim Patriack on the west coast started using the pump and cooler setups after the 1st year and several transmission failures.Hope these ideas help some what?