Officially Desperate, Asking For Help

[edwardzracing]

Well I'm sick and tired of trying to fight this transmission of mine and I'm sick of it not shifting so I'm here asking if anybody out there might be willing to share a tune that they know WORKS with their combination (assuming it's close to mine).

First I'll give a rundown of my setup.

'98 Camaro (99+ PCM conversion)
4L60E (mild build)
4000 Stall
4.11 Gears

Now the problem I am having is that the transmission will not shift at high RPM's. I'm starting to think it might be slipping the moment it tries to command the shift, but I'm not sure. Can someone please tell me what things I should log to see if the shift is being commanded??

I know my next request is a long shot, but I'm taking the long shot anyways. Does anybody have a similar setup as above, 4l60e with 4.11 gears, and have their car tuned and shifting correctly at say 6000 RPM? I tried lowering my WOT shift RPM's down to 5800 and it still will not shift under WOT. It shifts fine cruising around, but refuses to shift out of 1st or 2nd when under WOT.

If someone can share their tune, it'd be greatly appreciated... I'd love to compare my tune to someone else's to see what might be different. Now I have a good sized cam, and decent heads, a fast 90/90 combo and a high stall converter as well, and I understand all of this factors in, but c'mon, the damn thing should shift at 5800 RPM unless something is seriously wrong in the tune or I have a mechanical issue. I figure if I can get someone's good working tune... and the problem persists, I can probably blame the issue on a mechanical issue or lack of transmission fluid. Whatever the case, I'm desperate for help. I did increase the shift pressures, but not dramatically. I don't know for sure if the transmission has a shift kit in it or not, but would increasing the pressures cause the transmission to NOT shift with a shift kit?? I'm beyond lost at this point... I'm the first to admit I'm not that great at tuning, but if someone can share their good working tune with a similar setup, I'd love to see where my numbers are at versus theirs. BIG THANKS to anyone willing to help. Thanks to all those that took the time to read my repetitive post, lol. This forum is top notch.

Brad

[LS1_Dragster]

As always when requesting help....post your tun file and a log!

[ScarabEpic22]

Remember BOTH RPM and VSS conditions must be met before the trans will shift. The easiest way to setup WOT shift points is to set the VSS low and control is via RPMs. Id rather have my trans shift at 6500 rpms (or 6000 in your case) at WOT rather than at 40mph.

Guesstimating here, with 4.10s, a 4L60E, and 6000 rpm WOT Im thinking it should shift around 40mph. My TBSS has the same setup but shifts at 6500rpm around 44-45mph.

Post the log up when you have a sec.

[joecar]

Also, make sure the WOT downshift MPH is lower than the WOT upshift MPH.


Try going lower, set WOT RPM to 5000 rpm say, and as Erik said also bring the WOT MPH down (and see my comment above)...

if you can get it to shift, then work the RPM up until it shifts where you want.

[edwardzracing]

Thanks for the responses guys. I've put the transmission tune back to stock and then used the calculator to adjust some of the shift points... I can tweak as necessary if I need to, but the goal is definitely to get it to shift at WOT. Can you guys tell me what PIDs to log for the transmission? I will post the latest tune and log file after knowing what it is I need to log. Thanks again!

Brad

[minytrker]

Did you try the settings I sent you yet?

[edwardzracing]

Yes... well almost. I'm going to test one more time by zero'ing out the WOT mph tables just for sanity sake. I left my WOT MPH settings, and nothing changed... it still fails to shift. For some reason it didn't show "commanded gear" as a valid parameter to log either, so I don't know what the deal is there. Log seems to say it's changing gears, but it certainly doesn't seem like it in the car, and the RPM just continues to rise in the log... doesn't seem to show that it's shifting even though it says so. I've attached a log and the tune I used this go around. I used most of the stuff in your tune, Lorenz, but kind of combined mine with yours being as some of the settings in yours aren't exactly setup for the altitude here in Utah, like I will never ever see the 90+ columns from my MAP sensor.

Anyways, thanks a ton for your help, Lorenz. I don't know if these files will shed any light on the subject or not, but here you guys go. I think my transmission is just a done deal... AGAIN. Thanks everyone.

Brad

[minytrker]

Whats you MAP at WOT, I didn't think about you being at higher altitude, just shift my 100 column to where your at WOT and blend over 3 columns. The rest of the things I changed you should try 100% like I had them to see to rule out the trans, if you didn't use all my transmission settings then it still won't tell you anything. Does that log go to that tune or the tune I sent you? If you wonder why I changed some things fell free to give me a call tomorrow and I will go over it with you. I never mind helping someone when I know they are trying to learn.

[minytrker]

Holy shit....7500rpms....thats why I lowered your shifts points and the rev limiter so it wouldn't be revving so high if it didnt shift. If thats still a 98 motor I wouldnt even rev it to 7,000rpm. Looking at that log the pcm though the transmission shifted but according to the rpms it didn't, looks like the trans was slipping.

[edwardzracing]

I'll move those columns to a lower map and try your tune full on tomorrow. The motor is no longer a 98. It's still the 98 block, but I have the good beefy LS2 rods and the 2004 LS6 pistons (floating setup) with ARP 2000 rod bolts. It should be able to handle the RPM. I have a 240/242 cam with just over 600 lift, so it likes RPM. It was still pulling hard at 6800+. I just have my shift rpm's low to simply try and get the thing to shift. I'll make that slight change to the tune you sent me and load it up and make another log tomorrow. Thanks again, Lorenz.

[minytrker]

Well I feel alittle better about the RPM but I doubt your still making power above 7,000rpm. I have a 251/259 with over .660 lift and with a single plane and it only makes power to 7,000-7100rpm. 7500rpm is still alot of rpm for LS2 rods, I wouldnt turn the motor that high if it were mine.

[joecar]

In your log I see that there is no rpm drop on 1->2 and 2->3, and on 2->3 I see the rpm go up... this indicates internal slipping.

[LS1_Dragster]

This might be dumb, but what if it thinks it's in performance mode? The performance mode shift points are sky high. I always copy over the shift points to the performance, hot and cruise colums....

Lee

[edwardzracing]

Guess it can't hurt to double check. Thanks, Lee. Feel free to drive 25 miles north to Layton and come for a ride with me to see what you think, lol. I appreciate the thought... I'll make sure my performance, & hot numbers match the normal ones. Thanks again to everybody for their input. I will post back again later tonight with another update.

[minytrker]

Did you try again yet?