jkerr

Gang, I've searched extensively on the site and can't find what I'm looking for. I'm hoping you can help.

I recently got a RIPP SuperCharger and a Diablo programmer. I have an Unlimited, automatic, 5.13 gears and 35" tires. RIPP does not change the automatic shifting points from the stock ECM configuration, gear ratio or tire size. Their ECM program only modifies engine performance tables (e.g. VE/Timing/etc). The stock transmission management program is junk. I need to firm it up a bit.

I'm going to dyno tune this weekend and would like to have them optimize my shift points (e.g. normal driving and full throttle). I'm basically trying to get the Diablo/RIPP program similar to how the SuperChips Tow Tune manages the transmission.

What have you guys found is the best RPM for an automatic to shift from 1-2, 2-3, 3-4 for normal driving and back down? Red-line is currently set stock at 5600. What are your thoughts on bumping it up to 6K?

Any other suggestions or things I should keep in mind are much appreciated. Thank you for your help!

RIPPMODS

Typically you shift where your HP peaks - rule of thumb. So when you go tuning the optimal shift point will spell itself out. However when tuning you're going to want to play with trans reaction vs throttle input to compensate the overdrive lock up -

What your asking is gong to be hard to answer - but we look forward to input from the community...

Great question - perspective - thinking...

TECH

CerOf

Don't you want it to shift just a hair past the peak so when it shifts the RPMs don't fall off too much and the next gear is a bit snappier? Or does it even out?

jkerr

SuperChips has a good default transmission management program (SuperChips Optimized); however, they also sell a Transmission shift point add-on for those that want to tweak it further. I know there are JK'ers out there that have dialed their rigs in optimally. I've seen some comments about it, but I have not seen a thread that discusses the specifics. I'm hoping I don't have to spend hours on a Dyno trying to reinvent the wheel. There has to be a good starting point.

Fellow JK'ers, please share your thoughts about transmission management with us. Your comments will help everyone that wants to get the most out of their SuperChips or Diablo investment.

jkerr

Our posts passed each other. When you say past the peak, what are you referring to? @3K is seems to be where the power starts coming in. 5600RPM is red-line. Right now with a light throttle input, it is shifting about 2500RPM, which is too sluggish. I don't want to over-rev driving through the city, but it seems to be set in the worst possible spot now. Also, would the light throttle shifting RPM be about the same for all gears?

Thanks for your reply,

JPop

This has really been a lengthy process for Superchips and as RIPP said, the answers are quite complicated. Throttle position comes into play, where to kick down and quite a bit more. I've followed this pretty closely on my Dodge Ram and for now I am content to just stay with the Superchips optimized. There are a lot of different end user shift points available and the SC +1 setting was a little too aggressive for me.

As for where I would want to be with a street driven vehicle is shift points closer to peak torque when at 75% throttle or less. Above 75% and I am on board with RIPP.

jkerr

Thanks JPop, excellent and through answer as usual. I'd stay with SuperChips Optimized as well if I could, but I have to run a Diablo tune now that I have a SuperCharger. To guide the tuner, I'll have them calculate what RPM the JK is at when it has max torque on the dyno then set that as the shift point for all throttle inputs 75% or below for all gears. Is that correct?

For 75% or above, I assume that would then stay at red-line where it is now. Do you guys think it is safe to move red-line above 5600 to 6000 RPM on the 3.8? The manual guys seem to shift at higher RPM's without a problem. That will let me pull a bit more power out before shifting. I often haul a heavy trailer onto a hilly highway. I want to hold it in gear as long as possible to get up to speed.

Are there any points of wisdom on downshifting?

JKRoobi

I am also curious about this. I've been tossing the idea around of getting a Gen2 kit in the future, however I am worried about having tranny issues. Like you said, the tune that is offered doesn't seem to do anything for the transmission. And with the Superchips settings, all that is doing is pretty much increasing the line pressure, ultimately reducing the "slip" that occurs, right? That's all well and good for sure, definately better than leaving it in stock form, but what about everything else holding up in the tranny after the supercharger is installed? (clutch packs between gears, servo, etc.) Shouldn't other stuff be beefed up some? Just my

Tranny upgrades, along with proper tuning, is just something I've been considering to go along with this mod. Anybody elses input would be great on this subject. Thanks~

JPop

I know there are a few Diablo defectors that jumped back to a Flashpaq after the trans additions. I don't believe the SC trans tune is able to be ran without one of their custom tunes, but I'll poke around on the Dodge Ram forums. Also, the 545RFE transmission is quite different for those trucks with the oft grenading 2nd prime than the 42RLE found in the JK.

That said, I don't have an auto JK and really haven't dug all that far into what SC has done with their Chrysler PCM transmission work. It's there, it's available and guys are actively exchanging shift schedules on the Dodge Ram platform, just hasn't been a high priority for me.

jkerr

Thanks again for your help JPop.

FYI, I was poking around in the Diablo this evening. Here's how it is currently set (factory):

1st to 2nd
8%: 1439.95
10%: 3071.90
15%: 5855.81
25%: 9311.70

2nd to 3rd
15%: 801.58
20%: 1603.16
25%: 3259.76
45%: 5183.56

WOT for 1-2 & 2-3 is 5600 RPM.

These settings are a bit unusual. 1-2 for 25% is at 9311 RPM. Red-line is 6K. I'd never hit that. Similarly, 15% for 2-3 is at 801 RPM. I don't think the RPM's ever get that low when going form 2-3. Very strange.

It doesn't look like i'd want to set every % option at max torque. Any suggestions on where to start is much appreciated.

Thanks everyone!