trans temp sender location
 

Racers,

is anyone monitoring the cooler line outlet temp? [that is to say, the fluid temp as it exits the case] If so, tell me how you did the plumbing and did you learn anything useful?

Thank You

Re: trans temp sender location
 

Larry, I don't see many racers monitoring the trans temperature and there are many that don't even use a trans cooler.

If you plan to do so, I recommend you use something similar to the Peterson Fluid Systems sender plumbing with a smaller size line.

http://www.petersonfluidsys.com/plumb_inline.html

Re: trans temp sender location
 

I have a trans temp gauge in my car but the sender is in the pan. And I use a cooler as well. 200 - 250 is common on my car.

Re: trans temp sender location
 

You will be measuring the highest fluid temperature coming out of the transmission. Most production transmission run the outlet oil from the torque converter directly to the cooler.

Re: trans temp sender location
 

Larry,

I did this years ago on my 10.90/bracket car. Used a oversize brass 3 way fitting, bushed it down for the #6 braided hose I was using in and out. Dont remember the exact size, but was big enough that the probe in the center fitting did not hurt flow any...
I did this back before I was using synthetic fluid. Was setting up for .00x lights and trans temp/converter temp made a difference. Also impacted et's, but I used it more for my reaction time changes.
After I went to synthetic fluid, temps did not move as much, and did not seem to be as critical.
Just monitor pan temps now. But, also foot braking and not setting up for .oox's anymore either.

Look forward to seeing you soon.

Ken

Stock 412

Re: trans temp sender location
 

Ken, Thanks

We plan to test at Ennis July 25 and a date or two in August. Then the Lucas race in September at Thunder Road. be sure to look me up.

Re: trans temp sender location
 

The transmission fluid is at it's hottest at the stator. Unless you can place a thermocouple at the stator, the outlet side of the transmission cooling line going to the auxilary cooler or the radiator in-tank cooler is the best place. Place the probe as close to the transmission as best you can. Also, try to keep the probe away from an outside heat source such as the headers which could potentially give you a false reading.

Re: trans temp sender location
 

Are you going to come to Noble in October?

Re: trans temp sender location
 

Colby, most likely yes :) If you are there please be sure to look me up.

Re: trans temp sender location
 

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

Re: trans temp sender location
 

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
 

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.