Trans pressure tables with 58mm TB

**Thumperbass** · 04-26-2015, 10:12 AM

Looking for advice as to what people have done in their trans tables to compensate for a 58mm throttlebody.
I'm running a Cahall "race" build 4l60e and after installing the new 383 with a TPIS 58mm throttlebody I can feel that the low throttle shifts seem softer.
I'm running on a base tune from Solomon at this point and as far as I can tell all he has done for that was to bump the pressure up 3 points at the 0% throttle position.

**sweet-94z28** · 04-26-2015, 10:41 AM

I would add another couple pounds of pressure (2-3) at lower speeds if you want to firm it up a little bit. With any built transmission, I do not recommend touching WOT values as the valve body/valve body components are usually modified to make best use of the stock pressure settings. Sometimes builders will be specific on changing this, other times not. Part throttle stuff really just depends on the shift quality and how firm you want it. I try to make smooth pressure ramps that allow for comfortable everyday driving shifts, then firm, positive shifts when getting after the car.

***SSlowBoat*** · 04-26-2015, 02:49 PM

With franks trans I wouldnt go too far on changing the mids, what did you tell him for your shift firmness when he built it?

**Thumperbass** · 04-26-2015, 05:20 PM

I told Frank what ever he thought was best with the firmness. 1/2 shift was almost bonejarring and the rest just felt nice and crisp at all throttle positions.
My idea is to start with bumping everything up 3 lbs, up until the 18.5% tps in the table. Seems like everything above that feels fine.