Thread: Transmission Pressure Adjustable

Anyone know how ZZP is able to regulate their transmission pressure externally from the trans? This is probably going to be a question for trannyman

https://www.zzperformance.com/products_img/150_2.jpg

I've never messed around with my tranny pressure setting via my powertuner. What have you guys changed in your setting to make it shift firmer.

I have never touched my trans setting from my DHP v 1.5 burn. I've done tuning with LTFT, Maf, Timing, but never messed with the trans settings.

What they do is drill a hole in the side cover right behind the pressure control solenoid and install a pipe plug here so it can be removed. Only the 97-02 AC Delco style pressure control solenoids can be adjusted. There is a hex head screw on the back side of the solenoid that should not be adjusted but by turning the screw in it can slightly raise line pressure. Some transmission rebuilder tips have been to turn this screw in 1/8th turn and no more to help out with some pressure problems on a worn trans. The problem with removing the plug and cranking in on this screw on the pressure control solenoid is that the pcm will learn to this over time and because the shifts will be too firm and short the pcm will command lower line pressure to compensate for this and you will keep having to turn the screw in which should not be tampered with in the first place. The solenoids are factory calibrated to work correctly and once this has been altered the solenoid wont work like it should within desired parameters as it was intended. The best thoughts I can give to actually adjusting this screw is to ONLY do this at the track for WOT shifting which will only be a handful of times and the pcm wont learn that quick to it and then turn it back where you started when you are done. I have talked with a few guys that tried playing with this and they said exactly what I expected to happen and had to keep cranking in the screw to notice a difference because the pcm learned to the change and wanted to compensate by commanding longer shifts and lower pressure. It is best to adjust shift feel with the shift kit settings in the trans or with pcm tuning.