JTEC 46RE Part Throttle Shift Tuning

[Msmith68w]

Hello everyone.

I am a tuning novice, and am just starting to get my feet wet with this stuff. I figured I'd start someplace easy, and do a little tinkering with the shifting on my 2001 Ram 1500.

Specifically, the thing I would like to change is the 2>3 upshift at part throttle. The way the stock tune has it calibrated, if you're driving around normally (low throttle input) it will shift from 1>2 at something like 1800rpm, which is great. But then it waits in 2nd until 2400-2800rpm which feels way too long. Then immediately following the delayed 2>3 shift, it will make the 3>4 shift. So it feels like a long delay, followed by two shifts right on top of each other that happen around 40mph.

On the 46re, shift pressure and timing is largely controlled by the adjustment of the tv cable. Mine is adjusted to factory spec. Trouble is, adjusting that will change all the shifts, and that's not what I'm looking for. I'm hoping just the part throttle 2>3 shift can be forced to occur slightly earlier using the tune.

Looking under the transmission section (beta version required), "shift scheduling" tab, it would appear you could change this by adjusting the minimum and maximum TPS. However, I tinkered with it by lowered the minimum and/or raised the maximum in the middle sections of the tables (where the shift is or should be occurring) and nothing changed at all. Also switched to maximizing the minimum and zeroing out the maxium, still no change. Can anyone see any place else that adjustments could be made? Did I adjust the TPS table wrong?

Here's the stock tune.

Stock Tune.hpt

Thanks!

[spoolboy]

Try logging output shaft speed, engine rpm, and throttle voltage while this is occurring and post that file up. If there are channels for line pressure and/or governor pressure, log those too.

[Jim P]

If anything like the 48RE, there is some post shift acceleration requirements for shifts to occur that may be in play and timers as well.

[Msmith68w]

Try logging output shaft speed, engine rpm, and throttle voltage while this is occurring and post that file up. If there are channels for line pressure and/or governor pressure, log those too.

First time using the scanner, but here it is. Started scanning as soon as it shifted into 2nd at 23mph (which happened at 1824rpm). With 18% throttle it held 2nd all the way until 40mph (2634 rpm). You'll see I even backed off the throttle slightly before it shifted. From driving this truck for so many years that's just habit now. I lift a little at the top of 2nd to get it to shift.

Not confident in the output shaft speed measurement because it shows 20 while sitting still. It looks like the only supported output shaft speed variable in the scanner for this old truck though.


2-3 Shift Delay.hpl

[Msmith68w]

If anything like the 48RE, there is some post shift acceleration requirements for shifts to occur that may be in play and timers as well.

I would imagine that the programming for this would be nearly identical to a 48re since they're in the same trucks of the same vintage (only difference is engine). However, the only time delay I see is a 400ms delay for torque converter lockup after the 2-3 shift.

[Jim P]

Much like the 48RE or the 68RFE, hp tuners doesn?t have everything mapped out.

[spoolboy]

First time using the scanner, but here it is. Started scanning as soon as it shifted into 2nd at 23mph (which happened at 1824rpm). With 18% throttle it held 2nd all the way until 40mph (2634 rpm). You'll see I even backed off the throttle slightly before it shifted. From driving this truck for so many years that's just habit now. I lift a little at the top of 2nd to get it to shift.

Not confident in the output shaft speed measurement because it shows 20 while sitting still. It looks like the only supported output shaft speed variable in the scanner for this old truck though.


2-3 Shift Delay.hpl

Log again. This time don't lift to make it shift.

See if you can log more than 1 2-3 upshift at part throttle.

Also, increase your polling speed on output shaft rpm and engine rpm.

[spoolboy]

You can also try this file:2001_RAM_59_46RE (3).hpt

[Msmith68w]

Log again. This time don't lift to make it shift.

See if you can log more than 1 2-3 upshift at part throttle.

Also, increase your polling speed on output shaft rpm and engine rpm.

You can also try this file:2001_RAM_59_46RE (3).hpt

Thanks. I'm still figuring all this stuff out, so I'll give it another go later today.

I had no idea you could change the values in that far left grey column...haha. Learn something new every day.

[spoolboy]

Just right click and choose column or row axis depending on what you want to change and then choose edit. You can't change every table, just most.

[Msmith68w]

Spoolboy tune shift delay.hpl

Here's the log file for the tune Spoolboy put up. Doesn't seem to have made any change. The little part of my brain that goes "shift you bastard" starts going off at about 30-32mph (2200rpm) in 2nd gear with this level of throttle input. Shifts occur without a lift at around 38mph, but as late as 40-42mph.

I forgot to mention this (not sure if it matters), but the transmission does have a Transgo TFOD-Jr shift kit in it. Maybe the pressures are doing something goofy? Shifts great, just too late on this specific part throttle shift.

[spoolboy]

Jim P definitely knows more about this family of transmissions than I do. He is telling us there are tables missing - that he can probably see with something other than HP Tuners.

Also, I'm unsure about how much the governor and valves/springs in the valve body affect the shift points vs the software on these. A few years before the 46RE, the 518 was pretty much all mechanical except for the overdrive engagement and converter lock-up.

Was your shift kit the one that has the resistor in it?

[Msmith68w]

Jim P definitely knows more about this family of transmissions than I do. He is telling us there are tables missing - that he can probably see with something other than HP Tuners.

Also, I'm unsure about how much the governor and valves/springs in the valve body affect the shift points vs the software on these. A few years before the 46RE, the 518 was pretty much all mechanical except for the overdrive engagement and converter lock-up.

Was your shift kit the one that has the resistor in it?

Yeah, it's possible that I just won't be able to change it, which is fine. I've lived with it like this for 5 years, not the end of the world. Just a minor inconvenience.

No, it's this one: https://transgo.com/product-details/tf-jr-shift-kit/ Real basic. It's just a stock truck that I wanted to firm up the shifts a hair on while I was putting a reman unit in there.

[spoolboy]

Try these two files and log them. Let me know if anything changes.

2001_RAM_59_46RE (4).hpt
2001_RAM_59_46RE (5).hpt

[Jim P]

If I get a chance I'll take a peak in the background and see if anything pops out at me for any transmission parameters not currently mapped by HP Tuners. Likely the shift kit is playing a role in when the transmission can shift, shift kits modify pressures which is a piece of the puzzle when the 1-2, 2-3, 3-2 and 2-1 shifts occur. TTVA position, governor pressure, post shift acceleration calculations, timers and some other things are a part of what allows those shifts to happen at certain times. What HP Tuners has labeled as part throttle shift tables are part of boundary limits of when a shift is allowed to occur to prevent gear hunting.

[spoolboy]

Thanks Jim.

It's pretty frustrating being a Mopar guy trying to use HP Tuners. If we were driving GM products , things appear to have been mapped out much better for them.

[rays335i]

Thanks Jim.

It's pretty frustrating being a Mopar guy trying to use HP Tuners. If we were driving GM products , things appear to have been mapped out much better for them.

you are absolutely right!!! had a vet and you would be surprised or maybe not of what you can do. i am about to try the anti hunt part of the program you sent him. mnes are a lot lower(factory) and i didnt know which way to go (increase or decrease). mines shift to soon so will try that out too.as said some of this stuff is in there but has no effect when changing.hope anti hunt feature works

[[email protected]]

i have a 02 ram with the 46re trans and im wondering how to raise shift points

[Jim P]

Governor pressure, post shift acceleration and your part throttle min/max tables. There?s likely other parameters in there as well that aren?t mapped out.

[Jim P]

Boost and hold tables will come into play as well.