Pros/Cons using stock tune on built trans.

[McRod]

Hoping to get objective input on Pros/Cons of running the stock trans tune on a built transmission.

Tuner is Raceme Ultra. Trans is Stage 3 ATS 68RFE.

Truck + 5vr is 28k lbs. Pulled weekly. Goal is dependability and comfort.

I realize the aftermarket trans box tune for Raceme increases line pressure up to 225 psi. I am not seeing alot of difference in the shift points from the OEM factory shifts using the box aftermarket tune. But I do get a hard shift into 4th gear lockup if the throttle position is not more than ~25-30%. Soft footed driving around town can be alarming when shifting/jerking into 4LU.

Using the stock tune, I would think, would soften the shift with lower line pressure. The trade-off being more slip in the clutch pack. But since the tranny is built it should provide better longevity. Is my understanding incorrect? Looking for solutions I can implement myself.

 0 Comment(s)

[Aj Grubb]

I believe you are thinking about this correctly. Increasing line pressure can cause harsher shifting. A custom tune could probably soften the shifts by lowering the line pressure at lower throttle percentages and raising it back up at higher throttle percentages.

I don't think running stock line pressures with your built trans would ruin it immediately or anything like that, but I would not do it if I were in your position. The transmission was probably assembled with increased line pressures in mind. Also, as I assume you already know, increased line pressure increases the holding capacity of your clutch packs. Towing as heavy as you do I would prefer to deal with some harsh shifting if the trade off is less risk of slipping my overdrive clutches.

 0 Comment(s)

[RamIt]

Box tuning on a built trans is a bad combo. The Ultra max pressure I believe is 180, not 225, I may be wrong.

Soft shifts are the death of transmissions, you want the gears to lock hard and fast to avoid slippage.
Also, custom tuning would allow for lock up as early as 2nd gear which would help promote longevity.

I'd suggest speaking with a tuner and getting some input, especially since you are towing.

 0 Comment(s)