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comparing a 2019 trailhawk elite with 2.0T to a 2020 fwd limited with 2.4L

5K views 56 replies 8 participants last post by  MikeR. 
#1 · (Edited)
Just so happened to choose a 2020 fwd limited model with 2.4L as my rental car. It had 18500 miles vs my 2019 (3 years old with 13500 miles) Here are the biggest differences:

  • can really notice how much lighter it is
  • can really notice how much lower to the ground compared to a trailhawk with a 2in lift
  • better gas mileage
  • really slow. I keep putting my foot down looking for more power and get nothing
  • transmission shifts much smoother
  • steering is tighter
  • the leather seats are much better than my elite. Softer leather, they feel more cushioned (like more foam or something). I'm not sure if the seats are actually supposed to be so different or if my vehicle is just weird, or something. This limited had no ventilated seats and my elite does so perhaps that meant they couldn't fit as much cushion inside. I don't know.
 
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#49 ·
So I posted earlier the engine torque of my tuned 3.2 not an entirely fair comparison to the stock vehicles we are talking about.
Here is my 2014 which isn't tuned in this video (obviously not making as much torque as my modified one) but the interesting part is that it only drops engine power during the 1-2 shift and the torque does stay more consistent vs the turbo.

 
#50 ·
I tried to get a 3rd gear pull from around 2K, to redline during lunch, but I had trouble with the alfa disconnecting. I have torque app and abd2aa set to auto turn on each time, so it sometimes give me trouble. I'll get it up this evening, but it should show the torque curve. You can really feel the torque start coming on around 2500 to 3000, but really starts to build just after 3500 and then drops off at, or just around redline. I'd have to go back and look, but maybe its dropping just a tad out of the larger powerband. It could even have something to do with the slow shifts, where it takes just a second to spool the little bit it lost during the shift.
 
#51 ·
Manual shifting doesn't work the best another option you could try is instead of full throttle going 3/4 throttle or so, you would then have the vehicle upshift at a lower RPM however then you can't use sport mode because it holds gears longer at lower throttle input. I think i've got it figured out. Let's just assume the worst and that you can't tune the PCM but the TCM is supported and you can make changes (granted its expensive)

Refer to this picture below showing the shift patterns for auto and sport mode



The column on the left is accelerator pedal position pretty self explanatory, I drew a line at 50% throttle on the sport mode table you can see that even below 100% throttle it's nearly shifting at the maximum (6500rpm) so letting off a bit in sport mode isn't going to work.

Now if you look at the top table even though in auto mode the transmission shifts at the same RPM at WOT it will shift a bit lower if you get it less than full throttle.

So the easy and free solution is to find just the right amount of throttle to get the vehicle to shift at around 4800rpm and not start to run out of steam as RPM's rise.

If you were to tune the TCM you would just lower the values for WOT throttle shifts and then you would be able to keep the engine in it's narrow power band longer. Its sort of a band aid fix but it would work.

I don't really want to elaborate too much further (we could go to PM's) since there is a jackass posting in another thread and I don't really want to give him any info for "tuning" his vehicle, but this is good progress so far.
 
#52 ·
I'm not really trying to get any more power or speed out of it. Its got plenty for me. I'm more or less just trying to understand the torque curve, and figure where the sweet spot is to get the most feel of the torque. I think the slow shifts from the transmission are holding it back more than anything, and not sure there is anything software related that would significantly change that.
 
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#57 ·
@Tyler-98-W68 I finally got around to the 3rd gear pull. Started down below boost curve to see where it starts to come in. You can see a lot more detail running it at .25 speed. Also did another 0-75ish mph run with graphs turned off to see if it would help refresh rate.

3rd Gear Pull


0-75ish
 
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