Auto Tranny upgrade - Expertise needed

[stevechumo]

I'm thinking about installing an extra oil pump with adjustable speed control inline with the tranny. The reason is to speed up the flow speed of the oil, thus it can cool down the temperature quicker through all the gearing in the tranny. Another advantage is to keep the fluid viscosity not to be broken down by the heat.

I'll be installing the pressure gauge to monitor the stock pressure vs. the increase pressure from the oil pump, then maybe I'll just increase the speed a little bit more.

I see the important part of the tranny upgrade kits out there use bigger valve body to increase the fluid flow. That's why I though of using this extra oil pump.

I already have the extra tranny cooler, but I don't think it's enough when I more than double the hp and tq of the engine.

Does anyone have any input? Where are the experts in this area? Please jump in...

 

[XR8tt]

In most cases they increase the line pressure so shifts are lot quicker..
The faster the shift the less heat, friction in auto..
Keeping ATF fresh and changed often helps..

 

[stevechumo]

Will increasing the line pressure cause the jerk when the tranny shift? My high stall rate torque converter already has enough jerk through shifting.

 

[XR8tt]

It will shift VERY quick.. On light throttle it may hit hard ?
But strange enough, they seem to smooth out at higher throttle opening...

 

[jibbby]

Hi Steve, I upped the line pressure in my previous auto tranny, and yes it did shift faster, slightly harder but not jerking into gear when rolling...However, the jerk and or clunk will be most evident when shifting from Park to Drive, Drive to Reverse, and when shifting at a stand still...

I would say it's a good idea as I do believe it makes the tranny perform a bit better... Just keep in mind that you will loose some of that Luxury Lexus feel when upping the line pressure... It won't shift as smooth and softly as stock, but it's not that bad a difference..