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In attached log i see the 1>2 is commanded at 5740rpm, then some TQ mgmt is applied,
but it never shifts and hits rpm limiter around 6700rpm. Normal street driving is ok. Anyone see this?
Recent Mods:
MMX Max Effort NA cam kit
longtube headers & hi-flow cats
Circle D 3600rpm stall converter
Hellcat throttle body
180 degree thermostat
2019 Dodge Challenger Scat Pack 6.4l
I don't think I'm hitting a tq/safety-type limit (initially) so all I know to try is add more TQ Mgmt (more than stock) and increase Shift Timing. I've already added a good amount of Shift Pressure. Open to other suggestions/feedback.
Car only dyno'd at 475whp/485tq so I'm surprised its having so much trouble w/ shifting but the high stall converter could explain it.
Looks like you need a lot more Torque pulled out so the trans can actually shift it with the crazy high Pressures you're commanding.
You're in MAX mode during the shift that's barely pulling any Torque,( -54Nm according to that tune).
Sport and Normal mode pull close to -300Nm.
An easy test is to lower the pressures back to stock in 1st Gear and switch to Normal mode and see what happens.
Thanks for the reply.
Yes, during that pass it was in Max mode which is somewhat of a fluke as its usually in Sport such as this pass (log attached). Notice in pass3 a good bit of TQ Mgmt is applied, and trans commands 1>2 shift at 5737rpm but it still pushes through the shift. The rpm drops very slowly (not sharp) when TQ Mgmt is applied for unknown reason.
Attachment 114462
https://www.dropbox.com/sh/gdv6qshf8...-garfGPaa?dl=0
Lower 1st gear pressure back to stock so the C clutch has an easier time releasing.Quote:
Originally Posted by shak3r
You can turn the Fuel Cut back on too
Thanks for the feedback! I'll try those suggestions this Saturday at a TNT event.
To clarify, stock trans settings would not complete 1>2 shift either under WOT at prep'd track. But in hindsight that may have been more related to the shift schedule (too late shift) than anything else. i.e. The OSS rpm is way different bet/ the stock and 3600 stall converter.
If you were slipping bad in 1st even with the Stock Trans tune, you may just have a transmission issue ei: smoked E clutch.Quote:
Originally Posted by shak3r
Once the converter is over its stall speed, the OSS isn't going to vary much from stock, even if its not a stock modified converter.
Yesterday I ran 6 passes total:
1st pass: Did not complete 1>2 shift
2nd pass: Completed 1>2 shift using only 60% accelerator pedal.
3rd pass: Did not complete 1>2 shift
4th pass: Completed 1>2 shift using <54% accelerator pedal. (Bracket elimnation round)
5th pass: Completed 1>2 shift using <48% accelerator pedal. (Bracket elimnation round)
6th pass: Did not complete 1>2 shift using ~100% accelerator pedal (Bracket elimnation round - eliminated)
A common theme when shift does not complete is the Clutch Shift Type is somehow getting set to MAX. In later tune revs I tried to disable MAX w/o much luck.
All passes were ran in Track drive mode so I was adjusting shift schedule pattern 9 throughout day.
Link to logs/tunes and vids below. Thanks for any feedback!
https://www.dropbox.com/sh/d2swqd44d...mWIz3G6na?dl=0
NVM, I'm going to cut my losses and move on from the 3600 Circle D converter. I've got at 1320 torque converter (2350 stall) on order. The Circle-D converter will be up for sale -- might work better on the (HP70) RAM trucks?
Sorry to be late to this but did you ever figure out the problem. Im haveing the exact same issue as you, but ive git a 5.7 with a factory convertor
what's the price you'd be willing to let that 3600 circle D go for? I've got a 2016 Ram with a stage 3 cam that would be a perfect match for that stall size i think...
Just confirming replacing the 3600 Circle D w/ a 1320-spec'd model resolved my shift issue. The Circle D wanted to flash to the moon (6600+ rpm) which was not realistic w/ stock pistons. A 3k spec might have worked.
I already sold the Circle D to guy w/ a RAM :)
I actually also have one of the 1320's installed in my 2016 Ram but havent quite made it out for a drive just yet. trying to iron out this trans engine torque request or whatever is putting me into limp mode and Ive also come to the realization that my timing almost had to jump a tooth so Ive got the front of the motor torn apart as we speak and am resetting all the timing marks now and hopefully have that wrapped up sometime tonight. Im hoping the timjing is the cause for all these issues but Im not holding my breath or anything. But I myself am quite curious of how this 1320 converter with its lower stall set at 2350 is going to fair with my Ram setup. Its the one move Ive made that Ive been second guessing and going back n forth over. Worried it may not be enough on mine as far as the stall size goes anyway. How is your setup fairing for you using the 1320? Is it what you expected? And how exactly did you go about tuning for this particular converter? Any feedback and/or advice is much appreciated!
I essentially kept the stock trans (including TQ) settings of my Scat. If you talk to 1320 guys you will hear about intermittent bad shifts. I choose not to blindly import their trans tune settings to avoid that headache. I improved my 60' slightly (less than .10) w/ the 1320 converter. My best so far is 1.670 (2078 DA).
you did nothing else but switch the stall convertor? ive been debating getting one for the same reason as you because ive had no luck fixing the 1-2 shift not happening via the trans tune. i just really dont want to spend $1000 on the convertor and hundreds more in labor for nothing. i dont really race my car, its a daily, but i do enjoy having funQuote:
Originally Posted by shak3r
If you have a stock TC it should be shifting w/o issues so I'd be hesitant to replace the TC too. Are you sure you're not hitting a max TQ limit vs rpm limiter? Did you post tune/logs/vids like i did above?
FYI, read this post about some (3) of the TQ limit tables. This is not an inclusive list but may be helpful...
https://forum.hptuners.com/showthrea...l=1#post665706
I'm sure my stock TC would have worked fine but I opted to upgrade to a 3600 during cam swap and it never worked correctly. I reverted to a 1320 TC and its been working fine w/ stock trans tune.
Attachment 120998Quote:
Originally Posted by shak3r
Attachment 120999
these are my trans and engine tune right now, I haven't been able to confirm if it works or not. i see your torque convertor doesn't engage 1st-5th, is there a reason for that?
also i do not believe i am hitting a torque limit
Same Issue!Quote:
Originally Posted by shak3r
1-2 holds @ 50% or lower throttle, above that will trigger rpm limiter and limp mode. WOT shifts from 2nd or higher are fine. Prefer to resolve 1-2 shift issue before dyno.
comp 270 cam kit
ported heads
whipple 2.9L @10.3lbs boost
long tube headers
Circle D 2800rpm stall converter
90MM upgrade throttle body
180 degree thermostat
6.4L w/forged internals
Hello!Quote:
Originally Posted by Enthusiastic
Could you share your tune and log?
DodgeBoy.
YouTube: https://www.youtube.com/@dodgeboy2785
how did that dyno session go?Quote:
Originally Posted by Enthusiastic
DodgeBoy, I responded to your email. Thanks.Quote:
Originally Posted by DodgeBoy_8HP
i fixed another hp70 tune at the track tonight
scat w 3500 convertor that had lost 1-2 shift
lemme know if you need help
Had delays due to fuel delivery issues. Dyno scheduled for next week. The compression is lower on this forced induction 6.4L (9.7:1) to run on 93 octane pump gas. Hoping for 550-650 (Dynojet dyno), or 450-550 (Mustang Dyno) as a baseline range with only 63lb injectors and 10psi boost.Quote:
Originally Posted by LilSick
Adding another 300Hp with bigger injectors and a smaller supercharger pulley may not be a good idea for the stock ZF 8HP70 :doh:
OK. Thanks!Quote:
Originally Posted by LilSick
My first pre-dyno test was a 5.0 Mustang yesterday, on a second gear rolling start. Smoked it. I got a lot of WTFs and laughs. Since the new "stock" Mustang comes with anything from 315 to 480 HP, it probably was not the top performance stock version at 3,752 lbs. The fat 6,600 lbs. of Durango with 3 passengers in it without SRT or Hellcat badging was not supposed to do that :banghead: :o
How did you fix the 1>2 shift?!? It wont help me now, but I'm sure others would appreciate the info :)Quote:
Originally Posted by LilSick
it sounds crazy
spoolboy knows, he did not call me nutz
some of the switches got reversed somewhere during the latest revisions
thx hpt
DYNO RESULTS - 562WHP (SAME AS STOCK HELLCAT DURANGO):Quote:
Originally Posted by LilSick
Example Stock Hellcat Durango Specs and Dyno Reference Comparison:
Using an 8HP95 (900Nm) transmission, a "stock" 2021 SRT "Hellcat" 6.2L Durango produces 562WHP/531WT (according to Hennessey Performance) on 93 octane pump gas with stock tune, 9.5:1 compression ratio, 11.6 lbs. boost, and 57lb (600cc) injectors.
https://www.youtube.com/watch?v=n4WenoBjHjo
My Specs and Dyno Numbers:
Using an 8HP70 (700Nm) transmission, My 2017 Durango with forged 6.4L (392) produces 562.87WHP/524WT (Dynojet, yesterday) on 93 octane pump gas with a conservative tune, 9.7:1 compression ratio, 9.8lbs. boost, and 63 lb. (661cc) injectors. My 6.4L engine has 2 lbs. less boost than the reference 6.2L Hellcat motor and seems to have the same power but only RWD with the 8HP70.
Additional 6.4L Power Options:
If I reduce the supercharger pulley size by 1/4" from 3.75" to 3.5" using the same 63lb injectors, this should increase the boost to the same as the Hellcat and exceed stock Hellcat power by 50WHP for a total 612WHP. The 63lb injectors may be close to their limit and may require 80lb injectors. Also, this may be too much for the 8HP70 transmission.
A 1/2” pulley reduction to 3.25” would increase my boost to 13.8lbs. and increase the power to 662WHP or 100WHP over a stock hellcat Durango. [UPDATE 01-18-2024] Done. Boost is now over 13 PSI, estimated 680WHP
0-60:
The 6.4L Durango weighs at least 6,300 lbs. with larger engine, SRT aftermarket 9.5" wide rims, and 295/40ZR20 tires. Not sure what the 0-60 would be as I have to let off throttle before the 1>2 shift to avoid limp mode, then I can go WOT. The stock Hellcat Durango claims a 3.6 sec. 0-60 on a perfect run, if actually possible, without special tricks including no rear seats, cold day, special tune, launch mode etc. Regardless, off-the-line using the same tires with even HP, the AWD 8HP95 Hellcat will do better than the RWD 8HP70. I should be able to get under a 4.0 sec. 0-60 on the RWD Durango with the current configuration.
However, with more HP (smaller supercharger pulley) past the 0-60, I should be able to reel-in the stock Hellcat even with groceries ;) :hi:.
Perfect! I just replied to you.Quote:
Originally Posted by Enthusiastic
Thanks.
I will be holding off on the tune. I found a deal with a great discount for a beefed up, tested, tuned, and installed 8HP70 good to 900WT (Ft Lbs. Wheel Torque). The highest I may ever get is 640WT. This should be plenty of room for longevity. Thanks!Quote:
Originally Posted by DodgeBoy_8HP
900 ft lb that means it comes with sipples billet drums
dont get burnt
dont pay 5 grand for a stock trans
No mention of this in our private conversationQuote:
Originally Posted by LilSick
on the phone i tried to suggest you learn how to set up scanner a lil better and log and find out if what you have is really shot before you swap it out
Hiw did you fix it? Ive got the factory convertor in my 5.7 and it wont shift until i hit the rev limiterQuote:
Originally Posted by LilSick
which version were you using when you wrote the last calibration?
I have a 2015 Ram cammed, procharged, and 3600 stall circle D. I am having this issue. How did you fix it?
In the past couple of months I have worked with a lot of RAM swaps (to ZF 8 speeds). It is quite a common issue.Quote:
Originally Posted by miccrohurst
The solution is a full transmission re-tune: Combination of torque converter, shift pressure, shift timing, shift RPM and line pressure.
Each case is unique (under my eyes). There is no "one size fits all", once every single engine and transmission are unique.
Thanks.
DodgeBoy.
YouTube: https://www.youtube.com/@dodgeboy2785
not by rewriting the entire tuneQuote:
Originally Posted by miccrohurst
just by playing with a few switches
i think they got switched in the software update
which version are you using???
If i posted my trans tune, could you look to see if anything looks off? Ive tried to fix it and had multiple Professional tuners look and try to fix but nothing worked.Quote:
Originally Posted by LilSick
sure
email me the current tune and a good log
I sent you an email with the most recent log and tune that was in it at the timeQuote:
Originally Posted by LilSick