HPTuners MPVI2—it looks like it is possible to program 42RLE shift points

psrivats

psrivats

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I was doing some reading yesterday, and it appears that HPTuners MPVI2 can indeed program 42RLE shift points on our TJs/LJs. See the reference thread below from the HP Tuners forum.

https://forum.hptuners.com/showthread.php?80875-2006-Jeep-Wrangler-w-Banks-Turbo
@Chris sold his Khaki TJ before he could fully experiment, but the screenshot from his earlier thread definitely hints at this as well (see left side of image). Does anyone else here have this software and explored these options?


1604937783490.png
 
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At least we know now that the shift points can be tweaked. I suppose that could make the 42RLE easier to live with. Though in all honesty, just turn the OD off and it behaves just like it should.
 
Tweaking its shift points still won't fix its biggest issue, its .69 Overdrive ratio. It's still going to have the same miserably low engine rpms after it gets into Overdrive unless you regear the axles. Making it shift better while getting there holds no attraction for me.
 
Chris said:
At least we know now that the shift points can be tweaked. I suppose that could make the 42RLE easier to live with. Though in all honesty, just turn the OD off and it behaves just like it should.
Click to expand...

Turning off OD helps but it is not the optimum solution, imo. I don't know how much you experimented with your khaki TJ.

Note: I have 4.88 gears in my axles for my 32s. It is likely going to be insufficient for 33s.



This is from the manual.

Overdrive ON:
1st, 2nd, 3rd, 4th, TCC Lockup in 4th gear

Overdrive OFF:
1st, 2nd, 3rd, TCC Lockup in 3rd gear

Note: The TCC will lockup in 3rd or 4th gear, not both 3rd and 4th gear.


I am not sure how much you remember, but I have observed that with OD off, the computer will immediately lockup up the TCC after the 2-->3 shift occurs irrespective of throttle position or load. The TCC remains locked until the load/throttle changes. If you start off with OD on (default operation), the TCC will not lockup until after the 3-->4 shift occurs and even then, only if load and throttle position allow.

I use the O/D switch frequently and it took me a while to understand what's the best way to use it. If I am able to continuously accelerate up to 65 MPH+, I just leave overdrive on. The transmission will shift through all of the gears at the programmed RPMs and when I am up to cruising speed and ease off the gas, the TCC will lockup.

If I need to drive between 40 MPH-55 MPH, I start with overdrive ON and then turn OD off after the 2-3 shift occurs but before the 3-4 shift. This allows the TCC to lock up in 3rd gear at high enough RPMs for it to remain locked. It's a pain to keep doing this every time I drive, so sometimes I give up and just not bother with the OD button at all.

I vaguely recall reading @mrblaine has written something similar here or on another forum. Cannot find a link. Please correct me if I am wrong in my understanding, Blaine.

I think with a shift schedule change this whole scenario can be made much better. That is what got me started on reading about this in the first place.
 
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I hated the 42RLE until I regeared. I'm on 32s with 4.88s now and I'm in 4th locked up at 40mph around 1500 revs and its completely livable. I'm a little high at 80mph on the highway but everyday drive is a pleasure.
 
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IAmTodd said:
I hated the 42RLE until I regeared. I'm on 32s with 4.88s now and I'm in 4th locked up at 40mph around 1500 revs and its completely livable. I'm a little high at 80mph on the highway but everyday drive is a pleasure.
Click to expand...

I have the same setup. On flat roads I can live with it no problems. But on any road with somewhat steep grade it's not as effective as I want it to be, esp if I am trying to accelerate.
 
Im not aware of any meaningful tuning on a JTEC PCM but im here to be proven wrong if anyone knows of anything.
 
HPTuners supports ALL TJs. I use Syked software for my tuning my 2004, but Syked does not have as much community support. I have considered going to HPT, but I'm slowly learning more about Syked.
 
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