OVA1

iTrader: (12)

Staged up at a track a couple of hours up the road from us. GREAT TRACK BTW: Bradenton… brand new surfaces on the lanes. Sticky as hell!

Got up there, opened the dumps and on the first pass after a quick burnout, the car literally left in third gear… NEVER DONE THIS BEFORE.

(Tranny is a BRAND NEW Performabuilt Lvl 3, with a few dozen passes and about 600 miles on it)

But I stayed in it, just to see what it would do and it didn't disappoint… it would not upshift into 4th. (I usually leave in the third gear slot, but it's never actually left in third gear before.)

Second pass, I picked up a NASTY wheel hop on the burn out.

It did this ONCE before, two outtings ago, when I had a passenger on an early pass (when there's decent track prep at our local track), but didn't do it again after he got out, or since… until last night.

After that, at launch, it did it again, very nasty… got right out, eased into the torque getting back in and as soon as it hit the power curve, it began hopping like mad… I stayed in it this time hoping to power through it, but soon realized that wasn't going to happen.

Nothing has changed in the physical setup. Same everything… same settings on the shocks.

What has changed is the PCM and the tune, but the programmer says that he didn't do anything but change the shift points, which are MUCH better, to be sure.

Any ideas?

Puck

iTrader: (17)

Bradenton is an awesome track.

Double check your TQ arm settings if you have an adjustable one. It could have come loose and screwed up your pinion angle. If its the stock TQ arm, I can almost promise you it is bent. Mine bent with bolt-ons after a couple track outings.

A real sticky track will exaggerate wheel hop since you wont have the spinning to ease it up.

OVA1

iTrader: (12)

Its the same UMI ATA that I've had on it for years. But I do need to get it on the lift to get a closer look. The UMI mounts on the tail of the tranny… and I have not cared much for that for a while now.

I've got a new set of BMR SFCs and their trak-pak sitting at the shop, which I've been meaning to get welded in, but no time during the week and the welder is not a week-end worker.

And Brother Puck, THAT TRACK IS FORE AND AGAIN STICKY! It's the only other track that I've ever run on and it is LEAGUES away from our local.

Long *** drive though… Next time I run up there, I'll be hoteling it… the drive up wasn't so bad. But the drive home SUCKED!

Got a nice bonus run with a 5.0 when I got back into town, but I wish it would've come on the front end… I needed the shot. I was coming down from all the angry adrenaline, due to the above crap… and all I wanted to do was shoot a beer and hit the sack!

Puck

iTrader: (17)

I have heard OSW has gotten better so I'm not sure if its still true(I haven't been there in almost a year, and even then it was on a bike), but Bradenton used to be so much better then OSW that I was willing to make the drive there.

OSW has a lot of noob bait though, you can catch a new driver in a nasty car but with no experience and chalk up some cool kills against cars that should have beaten you LOL.

myltwon

iTrader: (1)

What year is your car? Didn't see it posted.

Sounds like you got a nice case of "stall wall" basically means the tailshaft on the trans is flexing slightly allowing the VSS to temporarily lose signal, this locks the trans into limp mode. To correct this you need to adjust the shift tables in the tune. IIRC it involves having the 1-2 shift be set for 0mph and only based on RPM.

great421

iTrader: (1)

Air bags in the rear coil springs can reduce wheel hop issues - old drag racer's trick; learned it from my dad.

FYI - Remember to put 5 to 7 psi more in the pass side bag (vs. the driver's side unit).

OVA1

iTrader: (12)

Now that is good info right there and it makes perfect sense. I'll look and see whats there. Thank you.

OH! Car's a 96 Z29, but I just converted over to the OBD1 so we could tune it.

OVA1

iTrader: (12)

I'll give it a try. I was going to try that some years back, but after the suspension mods, the issue just disappeared, so I never got around to it.

Thanks much.

Puck

iTrader: (17)

If you converted to OBDI then it could very well be stall wall.

It naturally only effects 94 and 95 cars, which are OBDI cars with computer controlled transmissions. 93 uses TV cables, and 96 are OBDII. By going to OBDI, you may have introduced stall wall that needs to be tuned out.

myltwon

iTrader: (1)

Yup 94-95 only issue. When it happened to me I thought I roasted the trans or something, let the car sit a few min then drove perfectly. Finally researched it and it's actually a surprisingly not very talked about in regards to fixes, back in the day people used to throw in either 3 speeds or t56s to fix it because the knowledge wasn't as readily available as today.

cardo0

Check trans mount even motor mounts. My trans mount bolts worked lose after trans replacement and one fell out. A better torque arm mount would be to the trans cross member/floor pan or to a frame cross over if you have one.
Air bags are a big help and firly easy to install.

cardo