Im still here, but i do most of my tuning with efilive, not hpt. I will try to figure out what i need in the hpt scanner on friday and get some logs, but honestly this car is useless in putting power down on the road unless i roll on from 3rd gear. so i'll try get a 3-4-5 shift.
I find that with nearly all the 6l80's, u have to pre-empt the shift speeds kph/mph numbers to values below what you'd expect. having accurate tyre size/ppk values is also important too as different profile tyres will effect when it shifts.
Hi
I find this thread very interesting!
Do you have any experience tuning 8 speed trans 8L90 for GM cars or corvette C7 Z06 2015 +?
I have the same problems for 1-2 and 2-3 shift
I have problem with 1-2 shift at full Throttle. Engine rpm go to rev limiter at 6800 rpm, throttle shut down 50% , car slow down and transmission shift.1-2. throttle re open 85% and car re-accelerate.
blemI have reduce Full throttle RPM 1-2 to 5500 RPM, speed from 30 to 22 MPH.
I did Reduce shift time from 0.305 to 0.210 sec. Nothing work better!
Not very good for drag racing!
Please help me or give me the proper thread.
Thanks
The adapts are slowly lowering shift pressures in order to allow the shift event to happen within the specified target time.
Think about it.
Increased shift pressure will make the clutch pack engage quicker.
So I adjusted my shift adapt presets this weekend in addition to my previous tune. And it feels awesome at wot but it also seems alittle to harsh. I'm not sure if its good for the trans since its jerks so much, especially part throttle.
Heres a screen shot of my changes.
Should I lower the adapt presets down a bit from 550, 1150, 1700.
Do I have my shift pressure to high and shift speeds to low ?
Or should I give this a week to " learn" .
This is in a 500 wheel tvs1900 G8 with a Zl1 converter
Hows everyone doing long term?
Last edited by Maxspeed96ct; 01-22-2017 at 07:54 PM.
I don't use KPA, I switched mine to PSI.
In a truck those on coming pressures would be way high IMO, I have mine no where near close to that.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
try 250 in 0
550 in 1
1250 in 2
do a reset and see if that's better.
not every trans requires a lot of pressure, as they are often all different for wear, upgraded clutches etc. the adapts mainly helps the trans in getting the base pressure closer. the factory seems to run very low pressure from standard and then slowly works up. we are basically starting out high and then it'll learn down.
thats why it something that needs to be fine tuned on every box so that the adapts don't over correct and make the shifts sloppy again. or you can go the easy way out and turn adapts off. lol
250
550
1200 seems much better ! Haven't driven it much though
Now you guys don't tough the off going pressure preset correct ? Mine are all stock
I would suggest, if you do this, readapt and drive for a day or so with upshift adapts on, then turn off, dont just have it stupid hard.. let it adjust a bit.
Sorry to revive this post from the dead, but it's very much alive to me.
I must be missing something, I set all the values to 1700kpa and it shifts very firm love it! However, upon scanning, I only see 120 psi max on the oncoming PCS. Am I missing something? My trans torque values go into the 700s at some points, but it seems that pressure does not follow torque rise. Almost like there is a dead stop at 120 psi and I've updated the max pressure tables all to above that.
When I'm driving around or in Drive normal/special all PCS's are preset to 110 psi. I feel like I'm missing something simple.
Last edited by mourat; 09-19-2017 at 12:43 AM.
I have a 15 ss camaro with a BTR stage 3 and a CD 3500 stall and it shifts soft at the 1-2 shift when in 2 it locks then unlocks so im going to try these settings and see what happens, Blue cat helped but did not complety cure my problems at 1-2 but it shifts better but not hard at WOT like it should. we will see.
2015 Camaro SS Green Flash 6spd
BTR Stage 3 cam, Dart Pro 1 Heads, Circle D 3500 torque converter
Small shot.
on the early model ones i do for tapshift mode, but for the normal drive mode i still use it if i want to soften up the shifts. they also had a base shift time table too, so keep that in mind.
last august i bought back the car i ran the 10.5 in after the new owner i sold the car to busted the motor from running it on lower octane fuel. hopefully i should have a new combo in it soon, so i'll be playing with that again.
the drivetrain im working on is a 2010 6.0/6l90. I swapped it into an 84 2wd chev 3/4 ton so it weighs something like 4400-4500lbs. I did vvt delete, 228/230 cam, and valve spring so nothing crazy. its a cruiser but im not real concerned with having super soft shifts at part throttle as my daily/tow rig has a built/tuned 4l80 so im used to hard shifts. i want to try your method of setting up the trans but i want to get it right. if i remember correctly the base shift times on this trans are all 0's. so if that's the case do i 0 out the shift time adders? or reduce them by a %? or leave them stock? any help is greatly appreciated, these stock truck trans tunes are sooooo lazy, i hate it.
Post the tune.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
If I run 250 550 1250 is there any reason the up the base pressure? My stock tables start at 450 and end up at 1300? My thought was running your higher pressures in sport mode and then running your lower stepped pressures in normal mode
Sorry to revive an old thread with such important information. I have an L83 6L80e swapped 1987 Chevy Chevette. That's a 2k pound sedan.
I've read whole thread and have a question. Sometimes in my car when in tutd mode going from 1-2 and 2-3 I hear a pop like a DSG gearbox and I love it. What will cause that? Spark? I'll try this oncoming pressure change and don't want to lose the pop sound!!!
Is it when you're shifting at full noise? If yes, you're hitting the fuel cut