CLASS RACER FORUM - trans temp sender location

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Re: trans temp sender location

Quote:

Originally Posted by ATI Performance Products (Post 476817)

We don't see any reason to monitor it there. Just in the pan. You want to see an overall situation of the temp. Not the hottest coming out of the converter. You are usually the hottest at some point after the run once all the hot fluid out of the converter has mixed in the pan.

To us cooler pressure is more important. It affects converter flash and coupling to a point. If you have two transmissions and one has 40 psi cooler pressure one has 80....the same converter will act different.

There is a ton of adapter fittings though with 1/8th NPT holes and -6 to -6 etc

http://www.summitracing.com/search/b...=npt%20fitting

So, should we be looking at cooler pressure? And what do we want to see?

I know I went from another builder's setup, where they had bypassed the cooler in the case and the pump, to an unmodified case and pump, with a simple steel 5/16" line loop between the two cooler fittings, and saw over 400 less RPM for the same MPH, in a GM automatic with an 8" ATI converter in a Stock Eliminator car. But it did not seem to change the flash RPM, leaving off a two step set at 3200, the converter flashed to 5700 RPM regardless of whether the cooler was bypassed inside the transmission, or externally.

Re: trans temp sender location

Typically the converter charge pressure is regulated, this is what goes into the converter. The outlet of the converter goes first through the cooler, then all of that is plumbed through the lube system (gears, and clutch plates). If changing the case and pump affected the restriction in the cooler loop, it could change the converter charge pressure which could change the efficiency , that might get you the 400 rpm. The problem is you are getting less lube to the gears and clutches, which means more transmission maintenance, might be a good trade off if the on track performance is improved.

Re: trans temp sender location

Quote:

Originally Posted by ATI Performance Products (Post 476817)

To us cooler pressure is more important. It affects converter flash and coupling to a point. If you have two transmissions and one has 40 psi cooler pressure one has 80....the same converter will act different.

Quote:

Originally Posted by Alan Roehrich (Post 476835)

So, should we be looking at cooler pressure? And what do we want to see?

I have the same question as well. Also, I've understood that cooler pressure is lower than line pressure. Should line also be checked as a maintenance deal ?

Re: trans temp sender location

The problem with too much converter charge pressure is it will lead to a ballooned converter, and also pushes hard on the crankshaft, which could lead to crankshaft thrust bearing problems. Converter charge pressure is usually limited to around 100 psi.