66RFE Performance Programming???

[FlatbedHemi]

Just wondering if it was possible to reprogram the shift points for the 66RFE. I was just wondering if it was possible to raise the low end shift point so that it doesnt drop below 1500 RPM before downshifting? Just looking to keep it from lugging without having to manually shift it down or put more throttle to it, just so it cruises at 50-55 without lugging.

Anyone have any advice?

 

[Millnoff]

Hemifever tune and a moes 87mm tb. Fixed my 14' 6.4 with 3.73 gears.

 

[FlatbedHemi]

Not looking to get too crazy trying to add power. I just want to be able to use what power is there more efficiently. I am getting some 4.88 gears in it, which will help I know, but I want some options just in case it does still lug at lower speeds. I know I wont have that problem at higher speeds, and I may not have the problem at all after the swap, but I figured I would ask while it was fresh on my mind.

 

[olyelr]

I was just asking my jeep buddy about this yesterday. He builds jeeps and puts in newer LS type motors in them, and tunes the motors and trans etc. He told me I would first need an unlocked ecm (which he has), then tuning could be done. Until then, the trans tuning is what it is.

I am almost at my wits end with this trans. I absolutely love the truck, but cant stand the tuning of the trans. Using tow haul mode makes it better as far as upshifting goes, but then you get the hard downshifting when slowing down and 6th gear is non-existent.

I just keep telling myself.... * I will not go test drive an 8 speed hd truck. I will not go test drive an 8 speed hd truck * LOL

 

[FlatbedHemi]

I was just asking my jeep buddy about this yesterday. He builds jeeps and puts in newer LS type motors in them, and tunes the motors and trans etc. He told me I would first need an unlocked ecm (which he has), then tuning could be done. Until then, the trans tuning is what it is.

I am almost at my wits end with this trans. I absolutely love the truck, but cant stand the tuning of the trans. Using tow haul mode makes it better as far as upshifting goes, but then you get the hard downshifting when slowing down and 6th gear is non-existent.

I just keep telling myself.... * I will not go test drive an 8 speed hd truck. I will not go test drive an 8 speed hd truck * LOL

Didnt you have a gear swap done? What ratio are you running?

 

[22hemi13]

I was just asking my jeep buddy about this yesterday. He builds jeeps and puts in newer LS type motors in them, and tunes the motors and trans etc. He told me I would first need an unlocked ecm (which he has), then tuning could be done. Until then, the trans tuning is what it is.

I am almost at my wits end with this trans. I absolutely love the truck, but cant stand the tuning of the trans. Using tow haul mode makes it better as far as upshifting goes, but then you get the hard downshifting when slowing down and 6th gear is non-existent.

I just keep telling myself.... * I will not go test drive an 8 speed hd truck. I will not go test drive an 8 speed hd truck * LOL

Dont do it. It’s nice!!! Lol. I might be at my wits end too but now since mine is just off-road really I’m dealing with it. But man jumping out of wife’s truck into mine I feel like a turtle

 

[olyelr]

Didnt you have a gear swap done? What ratio are you running?

Nope, still running stock gearing, 4.10’s. Also have 35’s.

With the computer programmed for the 35’s it still shifts the same as the stock setup... which was ****** too. I never liked it with the stock 33’s either. My three main complaints are it lugs way too much, takes too much peddle input to downshift (which isnt smooth once it does it), and also it has this ultra annoying shudder that happens quite often when it is lugging. While regearing would help with these issues a bit I think, I also dont think it will completely rid the truck of these issues. Unfortunately I think a tune is in order.

 

[olyelr]

Dont do it. It’s nice!!! Lol. I might be at my wits end too but now since mine is just off-road really I’m dealing with it. But man jumping out of wife’s truck into mine I feel like a turtle

Yea, off road I have no complaint with the trans. Its just the on-road/highway driving that bugs the **** out of me.

And yes, when I get out of my work truck (‘17 1500 with hemi and 8 speed) and then hop into my power wagon I feel like it drives/shifts so incredibly ****** in comparison. The work truck is like a rocket and the power wagon seems like it struggles to try to get out of its own way.