View Full Version : Line Pressure
sndxrnd21mb
11-27-2001, 12:07 PM
Does anyone know if its possible to raise the line pressure in the automatic tranny, if so does anyone know how its done?? Through the PCM or is there an adjustment on the tranny itself??
Adjustment to the PCM can do it- There's a performance chip for the Grand Prix's T65-4E tranny- It is supposed to increase line pressure for firmer shifts. A shift kit with upgraded valve body springs will also do it- You increase the rate at which the valve body actuates- You can end up getting wheels between shifts if the springs are hard enough, but after about 10k miles, R.I.P. tranny...
sndxrnd21mb
11-30-2001, 12:21 AM
I dont want to run the tranny too hard, im just looking for firmer shifts for a little more performance. Plus, higher line pressure and firmer shifts actually extend tranny life. but everyone knows that if you beat the thing it will die.
EL CID has been checking with trans. perf. shops- I installed his tranny cooler. You may want to see if he's got info on the different kits available to firm up the shifts. I know with the GPs there's actually a trans chip that splices into the wiring harness (The Part is here (http://www.grandprixstore.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=GPS&Product_Code=224&Category_Code=004)).
Good luck!
reptar
12-12-2001, 02:36 PM
As someone who designs transmission pumps for a living, I'd say to be a bit careful here. The higher pressure could certainly damage your pump. I don't have any experience with the CD4E in particular, but I suspect the bearings don't have too much headroom to handle extra loads. In the extreme case, you might also experience valve stability problems, but that seems a little unlikely.
Good luck!