Procharged 05 GTO shift flare/ multi-disc converter?'s

[01 MidMet WS6]

Hello all I will try to keep this as short as possible, I am currently tuning a customers 05 GTO A4 w/2800 rpm PI converter, it has LT's, OR X-pipe, cat-back and most importantly a D1SC with a 6-8# pulley. Other than the torque converter the trans and driveline are completely stock.

Alright, so the engine is tuned, running real strong and making some stout power. The 1-2 shift is nice and strong, positive engagement when shift occurs. The problem is that the car will not make a WOT 2-3 shift. It gets to the shift point around 6000 RPM and flares up to the rpm limit and stays there. I have lifted very quickly when this happens because I do not want to damage the trans. Under normal driving conditions the 2-3 shift feels a little soft but not to bad. I have maxed out shift pressure for the 2-3 shift with no improvement and have also left in all torque management as well. Is this simply a transmission issue? I have searched this forum heavily and think that my trans settings are set up to the best of my knowledge/ abilities and am looking for any input. Thanks in advance!!

Also, if you want to comment on or have any engine tuning suggestion I also have a post in the Gen4 tuning section http://www.hptuners.com/forum/showthread.php?t=18262 feel free to comment.

Carl T

[timschot]

Anyone have any thoughts here? You can download the tune from the post he linked to, as well as some scan logs. I'm the customer in this case, and am searching all over to find info on the subject. I'm willing to purchase a built 4l60e or similar if necessary, but it seems like some people with even nice built transmissions have had the same issue, so I just want to understand the problem first. We haven't dyno'ed it yet, but its actually putting out right around 9 PSI, so I'm guessing it's somewhere around 500-550 rwtq right now, and will only get higher in the future. It's also worth noting that I had no problems with the transmission until I installed the D-1SC. The torque converter has been in there for about 2,500 miles with headers/catback with no problems.

Is there something we're missing in the tune, or something we could try to verify it either IS or ISN'T the transmission / power level as opposed to something we're missing in the tune?

Would putting the corvette servo or a billet servo in be a good idea? Or would that just break the stock band anyway? I'm curious what the engineers were thinking putting a weaker servo in a heavier car with the same engine.

I also think part of it may be that I have not installed the tranny cooler yet, but even after a cool startup and getting it right up to 160-170*, it basically does not want to hit 3rd until you let up or it bounces a couple times off the rev limiter. I stayed into it a couple times to see if it would eventually shift (I'm not afraid of breaking it... ), and it usually does after 2 bounces off the rev limiter, but in one instance it did bounce 3 or 4 times and I gave up.

Anyway.. This is getting a bit lengthy and I have work to do! Thanks for any help you guys can give us!

[timschot]

Well, I got real familiar with 2nd gear on the way home from work today. Started it up, drove about 2 miles, got to a stoplight, then at about 1/2 to 3/4 throttle acceleration it failed to shift into 3rd and then completely lost 3rd. No loud noises (but then again, I wouldn't hear much over the race bypass valve), but basically free rev in 3rd and d. No more 3/4 clutch pack, we think. Oops. So I'm looking at ordering a performabuilt level 2 4l60e.

So I'm guessing, as was the case with a few others, that my clutch pack was on its way out, and that's why it wouldn't engage 3rd under WOT, rather than a tuning issue. Guess that's what happens when you throw ~650 flywheel horsepower at a stock 4l60e in a 3800lb car...

On the upside.. the built 4l60e should be much easier to tune against with that much power!!