Quote:
Originally Posted by nlowell
I put mine after the stock cooler. It was actually recommended, since I live in SD, that I remove the stock cooler completely. I decided to leave it in for the time being. If I add an oil pump later then I might remove the stock cooler/warmer and try to put the pump in its place.
The center line on the stock cooler is the IN line and the outer line is the OUT line back to the transmission.
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I wouldn't recommend removing the factory heat exchanger from the system. You want the fluid to come up to temperature since viscosity changes with temperature. You may have noticed that the car shifts differently when cold compared to when it is up to temp. That is because the valve body orifice sizes were specified by the engineer who designed them based on the viscosity of the fluid at operating temperature. If the fluid is too cold and the viscosity is higher than the design parameters, pressure will increase and flow will decrease. You need flow through the valve body to actuate the pistons inside the transmission to engage the clutch assemblies.
Modifying a valve body generally increases the orifice size of certain fluid circuits to increase flow and consequently increase hydraulic pressure to the pistons and increase the normal force in the clutch pack assemblies (which results in a higher friction force). Running the fluid too cold will mitigate the modifications done to your valve body and you will not be reaping the full advantages that you paid to have.
In regards to a pump. Our transmissions use a gerotor fluid pump that is similar in design to an engine oil pump. As such, it has no problem moving fluid at higher pressures. In fact, the pressure regulator valve inside the valve body supplies the high line pressure necessary for valve body and clutch assembly operation (pressure the pump is already producing) and shunts excess flow through the torque converter and the cooler circuit. Having a slightly higher cooler circuit pressure due to a little added restriction is not even going to phase that gerotor pump. The pressure regulator valve is designed to prioritize flow to the line pressure circuit so even if the cooler circuit is demanding a little more flow, the pressure regulator valve will only deliver it if there is enough head room to do so without dropping line pressure. Having a slightly reduced flow rate through the cooler circuit during the brief interval that the transmission is shifting is not the end of the world here and OEM's do it all the time. Any pickup truck with a factory equipped "tow package" has an auxiliary air/oil transmission cooler installed in line with the factory heat exchanger. Adding a transmission cooler on this car is really no different.
Quote:
Originally Posted by Wayno
Yeah I also thought it would be better just to remove it and reduce as much restriction as possible as I live queensland where you still sweat in winter anyway.
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Haha...lived in Cairns for a year and a half and I recall the "coldest" winter night requiring a windbreaker and jeans. Even still, it's no 75 - 95 degrees Celsius that the transmission fluid should be operating at.
