I recently did a heads and cam swap on my car. Before the swap the transmission shifted fine. Now, after the swap and a mail-order tune the transmission wont shift out of first gear at WOT. Well, it will shift into second, but not until 7500 - 7800 rpm. During normal driving, it shifts into second at the right time.

I was wondering if this was a transmission problem or a tuning problem.

Any help would be awesome.

Joe

 

If the only change was the heads and cam, then I'd have to think you've got a transmission problem.

BUT...

I was running a mail order tune and everything was just fine. I installed a 3000 RPM converter and new trans and the car started doing a 1-2 shuffle at WOT. It would light up the tires in first, hit second and stop spinning, then go back to first, then a second later back to second and then it was fine.

Turned out it was the tune. The MPH values for the 1-2 and 2-1 shift were too close together. Loading a new tune that was based on my stock tune but converted for my 3.42 gears got it shifting properly.

Tuning problems are free to fix, if you have the cable and software.

Are you sure it's 7500-7800, the LT1's PCM I believe has a hard coded limit of 7200 RPM, it just shuts off there.

Is it maybe that you've not got the shifting tables set right for the 3.73's?

 

I believe that the shift points are set around 6200 or so. Madz28 did my tune and programmed it for the 3.73's. He seems to do really good work. I was just wondering if there may be something wierd or overlooked in the tune that could cause this.

Mainly, I am wishing that it is something in the tune and not having to rebuild the transmission.

Joe

 

Yes, it's very possible that the shifting isn't set right, even though Ion did it. He's only human and is bound to overlook something once in a while.

The mail order tune I referred to was done by him as well. I didn't want to mention his name because I don't want it to appear that I was slamming him. I am happy with what he's done for me, and happy with the tune. It's nearly perfect, and considering he's never even seen my car, that's saying something.

Ion is a good tuner, and definitely knows his stuff, but he can't get every tune perfect every time for every car. Just too many variables.

Have you tried talking to him about it?

 

I don't mean to sound like I am slamming him either. He does great work and I am more than happy with the tune. It is probably my tranny that is having the problem and not the tune. I had someone look at the tune and he said that the shift points are set correctly. I thought that maybe there could be something else that could cause it in the tune and I was just wishing that it would be something easy to fix and also less expensive.

Joe