Gtz, i guess you have a 2010 Camaro ?
Gtz, i guess you have a 2010 Camaro ?
sorry i got so wrapped up on the topic i didn't mention what kind of car.
it is a ss camaro 10
one of my buddies did mention that he didn't mess with tm or line pressure at part throttle or mid throttle. he only changed wot. swears he has no problems. it feels like to me especially at the track it is blowing thru the converter.
I made another change in the tune, i've been analyzing all the tables in the shift time and comparing the 09 G8's with the 08 vettes and 2010 Camaros. we have the same trans, and different ways to achieve a final desired shift time for various gears, but in the end the desired shift times are closer to each other when you compare final numbers out of the stock calibrations.
In my case, I changed the base shift times looking to make the shifts quicker, but i never payed attention to the desired output torque factor tables. in the G8 case, the 3-4 SP table have big negative values, -0.129 which if i deduct from a .230 base shift time, would make the desired shift times too quick.
Hopefully this is it, i'll load the tune tonight and go for a spin to see if something else changes. it's too bad i can't test this on the track, but hopefully we're getting close.
It's not about making the shift time inertia adder all 0's for the 3-4 table. in the 08 vette for instance that table is already zero, but there are other tables that add/remove from the desired shift time, and it never occurred to me to look at all of them and see the final number as a whole.
Last edited by bluegoat06; 02-15-2011 at 11:25 PM.
I can honestly say I haven't experienced this. However, I've never had my car at the track or have started off at WOT before a 3-4 shift is executed. I'm intrigued with this though. I'm anxious to see what you find out.
'09 MGM G8 GT
what happen here guys ???? what was the out come of all this !
yeah any resolution? Having the same issue now myself cts-v 2009
I don't think HPT has the programming parameters to fix this issue. None of the senior tuners has and answer so far via HPT. Not even The Tuning School. Only thing you can do is hotlap and without turning your engine off in the staging lanes.Originally Posted by scotedowd
I am trying to think back if I have ever encountered this issue, and I really don't think I have. I can't imagine an 07 vette would be much different from an 08. It sounds like an issue I would have noticed at the track if it was there. I'm going to look through my tune later and see if anything stands out as different.
2007 Corvette C6 Vert. A6
LME LS402, Pat G custom cam, ATI 10% OD Damper
Circle D triple disc 2600, 3.42 Diff
YSI, 3.0 pulley, ID 1000's
Alky Control Meth,
ARH 1 7/8 headers,
1009 RWHP @ 7000, 817 RWT @ 6000
Take a look at the lag time on the 3-4 shift in this log. Then look at the 2-3. Big difference! Don't have a log where I ran a good 3-4 but I lost about a tenth and 1 mph vs. the pass I hot lapped.
If I can ask some newB questions.. Is this 3-4 shift thing primarily occurring when jacking up HP and torque?
This is when I first saw it... figured I was heading toward a phoenix pretty quick till I saw that it seems common. I did try the low rpm shift through 4th. Then "almost WOT" which produced a good shift. A tiny feathering produced a better shift sooo... this seems like it could be tuned.
So, then I assume if we "turn off" the car and back on...and do a cold to WOT (having read a bit more in these threads).. the slip comes back without another "adapt" hot lap.
SO HPtuners please advise is the stock adapt setting range too much.. looks like -21.8 to +21.8 ? So what would a more narrow range or wider range do to create "less adaptation" ?? In other words how can we keep the hot lap adaptation settings so that a cold WOT will maintain the adapted shift? ... or is this barking up the wrong tree?
Last edited by scotedowd; 07-18-2012 at 09:23 PM.
Does anybody have a solution to this problem yet?
Very dissappointing results with this tranny last night. Back to back passes gained 2.36 mph and .11 et with a good 3-4 shift. On the second pass I ran a quick part throttle run up to about 30 mph down the practice road to let the tranny shift normally up to 5th gear. Then without turning my engine off ran the second pass. You can see about a .8 improvement in shift times from the first frame where it shifts to 4th to where I regained advance.
My times were not as good as previous due to having extra weight in the car and poor air quality but a good test of the transmissions poor function.
It sucks for sure i fought the issue with the my G8 for a long time, sitting in line at the local track sucked since the lines were so long.
What i ended up doing that worked most the the time was doing a 2nd gear burnout and as i was in the upper rpms in 2nd i would let off the brake and bump the shifter up to 4th gear gearing while ending the burnout.
I even noticed this at my track visits in my new to me C6. i have the 2.56 gears but since i run a 25.7-25.8 tire at the track and trap in the 122 area which the 3-4 starts happening around 118 mph and lags at the top end of the track.
If i do decide to hit the track again this year for a new best i am going to try and disable the 3-4 shift completely and just end the 1/4 in 3rd. I currently have the limiter at 6700 RPMS and according to a online calculator i can do 126+ with the 25.x tire at 6500 rpms. Problem is with high hp apps like my old g8 i had to shift into 4th even with the 28" tire and 2.92 gears(was trapping 133-134 before i sold the car)
My plan for next year is to run the 305/35/18 Mickey which is a 26.4" tire and 6500 rpms in 3rd is 130+ Which will still work even when i add the cam it looks like (128-132 Traps) and by the looks at 6800 i can do 136 with the 26.4 tire.
I wish there was some fix for it as well.
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2009 G8 GT [email protected] 1.60 - Sold
2008 A6 LS3 C6 Cammed [email protected] 1.44 Sold
2013 CTSV wagon 9.21@151
2015 C7Z bolt ons 10.0
It would be awesome if we had some sort of way of telling the TCM to behave like it does when the shift has been completed in all 4 gears prior to the 1/4 mile run. What does it takes for somebody at HPT to look at the settings and explain the behavior, please please, Come on, we got this nailed down to the point where we need to do the burnout in manual mode and run the trans all the way to 4th, why ? come on HPT support, can you guys look and see if you guys can pin point the issue ?
Last edited by bluegoat06; 11-01-2012 at 12:25 AM.
I have this issue as well. It is killing me!! Before it wasnt too bad, but once I put the 3.27 gears in it put my 3-4 near the 1000 foot mark. It takes forever to shift. My pre 3.27 et's were 13.1 107 with a 2.02 60ft and after the gears it is 13.1 107.7 with a 1.98 60ft. ;(
So Im taking the plunge. The tuning school is local to me and Bob and I have a good repor with each other. Im taking his class on the 23-24 and cant wait!
Bluegoat: Ive been following your posts here and on the g8forum. I think we have spoken once or twice. Thanks for all the info you have been posting!
Don't think the Tuning School will be able to fix this. I would have already paid them should they know. I did work with them to no avail. I think it's just inherent of this tranny. Tuning won't fix it.
I agree.
My post may have been misleading. I am just taking the class to learn to to tune generally speaking. Bluegoat and I had spoken before because I was considering learning to tune and now I have decided to go for it.
I have a theory that the issue may be mechanical. Many trans servos and apply pistons have small bleeds in them that allow fluid to escape. So it is possible that over the cool down period described the fluid had bled out somewhat and it takes longer for it to fill and complete the shift on its first apply which would explain why hot lapping the cars or hitting 4th in the burnout box will correct the issue.
(sorry for the run on sentence)
Squirrel stuff
Or possibly the 3-4 shift adaptive is not a value that is stored? For example I work for chrysler as a tech and our nag1 trans resets shift adaptives every time you turn the car off. So maybe the 6l80 3-4 adaptive is stored in a region of the tcm that is "volatile" memory?
Was just reading this also. I had been wondering about it. If the trans calculated shifts off torque and the pcm is sending the wrong values.. This seems to be geared more toward cars that are mafless but if you add bolt ons etc to the car and make more power and most importantly torque the pcm wont know.. Right? So we need to adjust the tables for the calculated engine torque so the trans knows how much twist its getting?
Plz correct me if Im off base here. Im a newb..
http://www.hptuners.com/forum/showthread.php?t=42081
4 months later and I wanted to try this again, Chris/Bill or anybody from HPT who can check, could you guys take a little bit of your time to check this issue ?
It would serve those of us tuning 6l80e's a tremendous help, it cannot be possible for us to trick the trans doing the 1-4 shift in the burnout box like we have been doing since we have knowledge of the issue while at the 1/4 mile track, while on the street you'll never see this behavior, even if Mickey Mouse did the 3-4 shift point in the calibration
Last edited by bluegoat06; 06-09-2013 at 11:18 PM.
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