raceryan

Right now there is a 2000rpm T/C in my brand new GMPP 4L60/700R-4 (1993) Z28 Tranny. When you stomp the pedal, the car pulls great once it get's traction. But if you just drive normal, part throttle the car has the ***** of a 4 banger. IE driving along at 40 then floor it, it doesn't kick down, and speed just eases up. Or part throttle (40-50%) take off it feels like it's towing a heavy *** trailer. Is this normal for a stall? The car used to have a B&M 3200 in it, but the prior owner was eating rebuilt trannys every 4 months, (I think because he had no Tranny cooler and did city driving) The car was FAST AS HECK then. I never drove it, just rode in it. When I bougth the car from him after the 3rd rebuild in 1 year, I put the GMPP (GM performance parts) tranny in because of the 3 year warrenty. The car then drove like the above. If you drive it like a standard 1,2 D 0 it's fast a heck and squeals @ 1-2 and sometimes 2-3. After 3 months of this, I took the car to the dealer with the problem listed above and they spent 2 months tearing it down and changing parts, untill they put another new tranny in. It still drives the exact same.

I still have the original hole shot 3200 waiting to go in (it voids the 3 year tranny warrenty ) But I have never driven a car with a stall, so I don't know what It's supposed to drive like.

darrens99formul

It all sounds normal to me. The problem is the 2000 stall is not much higher then stock. I believe the stock TC is 1800 stall. That means a 2000 stall is not going to get rid of dead spots and that's why at certain speeds when you go WOT it feels sluggish (I know mine is a dogg at a 35 MPH punch).

The reason the previous owner went through trannys is because he didn't have a tranny cooler. With any 3000 or better stall it's a must get item. What you need is a 3000-3500 stall TC, tranny cooler and shift kit. Install all three at the same time and get ready for a kick a$$ ride.

raceryan

So That's why it ran like a bat outta hell with the old T/C in it.

I still don't really understand why it has as much getup as a GEO metro a WOT after about 30-40 MPH, especially with 4:10's. If it's stalled so close to stock why the huge difference in drivability?? Is it just not locking up? It's embarassing at a stop light if I'm behind someone.

Well, The GMPP tranny already has a stock shift kit, the cooler is in the garage waiting to go in with a 3200 B&M Holeshot. The only reason I'm holding on right now is because it will void the new tranny warrenty. I'll probably just put it in and if the tranny dies, put the original T/C in and pretend I didn't!

raceryan

I want it the tranny to kick down sooner, is there a way to adjust it?? Sometimes you have to double tap the gas to get it to downshift.

darrens99formul

I can tell you that the 4.10's should have helped the dead spots a little but I'm not surprised to hear that you have weak acceleration at 30-40 MPH. I have that same problem with my LS1. We have different trannys (mine is the stock 4L60E) but the sysmtoms are the same. The reason it's so slow at a 30-40 MPH punch is because the transmission is in second but under the powerband (1500 rpm's or so).

Now in a perfect scenario the trans would very quickly downshift to first so you could take off like a bat out of hell but it doesn't. Nothing is broken, it was just designed that way. At 25-30 Mph my car does downshift to first but not 30-40. There are only two ways to force the downshift.

1). you can do it yourself and drop your car into 1 and manually upshift. This is kind of fun actually since it almost feels like your driving a stick but it's bad for the trans. It'll wear and tear your tranny to death if done on a regular basis. I would only do this in an emergency (a ricer in a honda flips you off and punches it while your at a 35 roll).

2). get a minimum if 3000 stall TC. This will not force a downshift but it raises the RPM's into your powerband. Your car will take off at 35 just as it does at 25 and put a big smile on your face.

As far as hitting the gas a few times to downshift....

/shrug, sorry I have never heard of that before. Sounds like a tranny problem but it could be the TC in it. I would put that 3200 with tranny cooler in.

Good Luck