04 GTP 1-2 Shift slipping

[GTPNoga]

Grettings,
Lately I have been noticing some slipping in the 1-2 shift when the car is under load and above 4500rpm. Most noted at a WOT 1-2 shift.

Can someone take a look at the attached file to make sure its not my tune causing the slipping or if I'm over looking something?
There was a post about the 04+ Grand Prix GTP transmissions as they react differently to line pressure vs the 97-03 model years.

http://www.grandprixforums.net/f88/o...ings-2870.html

Also, what are the best parameters to look scan for then trying to diagnose this problem?

I'm running Dex VI and its at the proper level.

Thanks!!
Joe

[MMGT1]

http://i823.photobucket.com/albums/z...s_Settings.jpg

Set your shift tables like that if you can and lets have a go at this. Scan your car with the folowing config and post it. You need to be a little hard on it. Need to see your car shifting WOT.

Attachment 20999

Have you upgraded any mounts to polly?

[GTPNoga]

Thanks for the reply.. I will try it out today. I don't have poly mounds but solid rubber ones.

[GTPNoga]

Here is the scan. There are three wot 1-2 runs in there.

Frame Start 5782 first 1-2 WOT shift.
frame Start 7874 second 1-2 wot shift.
Frame Start 9848 third 1-2 wot shift.

Thanks!!
Joe

[MMGT1]

Set your hot tables to shift the same speed at 100% as well. Try an increase of 5% from 240 up in your shift pressure table and see how that feels. Have you removed some of the sensitivity of the knock sensor in your tune? They are way to sensitive in the 6's. If you reduce the shift torque reduction you should be able to reduce the desired shift time to .15 for your whole table. I understand that the 04 is different but with some changes there like above we will figure it out pretty quick. The big one on my mind right now is if you have desensitized the knock sensor yet.

[GTPNoga]

I increased the line pressure for the 1-2 shift and decreased the shift time. The knock decay rate has been changed but the sensors have not been desensitized. I have one of Russ K.’s tunes that he posted awhile back that has an aggressive desensitized setting so I might take the stock file and his and take the difference between the two. Just a bit leery about going agressive as this is my daily driver as well.

[MMGT1]

Trust Russ' tune. The 6's have a fluid sensor that is wayyyy to easily triggered. Mine has been cut in half and reaction to KR increased 4 fold because I know my timing tables are good. Three years later for me, countless runs down the 1/4, and this is my daily as well.

[GTPNoga]

So you lowered the Knock Retard Attack | Base Retard by 50% and then raised the Knock Retard Decay High Load?

[MMGT1]

Knock Retard Decay High Load is (X 4) and Low Load (X 2) Knock Retard Attack is (X 0.5) in mine

[MMGT1]

If this feels Ok then I would go into Trans>Torque Reduction>Normal Copy that table and paste it to your Performance Table

[GTPNoga]

Well I did another hard run today with the increased line pressure and the problem is still there it seems more pronounced as well. The trans has 40,000 on it of which 20,000 are my hard driving. I’m thinking the clutches are getting worn out and it’s time to limp it by until next spring and then get a new trans.

[MMGT1]

Could you post a scan of your car using this config?

LTFT+STFT(cruise_mode).cfg

Cruise for a good 15 mins before you start to scan. Then get a good 15-20 mins loged and post it.