speedo recalibration
 

I have 2002 Z/28 with the usual bolt ons, Automatic trans. I had a mail order tune and the car really ran great with 273 gears. I did some suspension work and the car hooked up great but the engine bogged, so I switched rears and istalled 342's. Took the car out, and it ran like an animal, except for the fact that the speedo was off. Sent the PCM out for recalibration, and when it came back the car is a slug. It seems like it goes through the gears to fast. Under normal driving it shifts into 2nd gear at around 9 MPH and into 3rd at about 20MPH and into OD at around 35 MPH. I didn't notice what MPH it shifted at when I got on it but it seemed like it shifted way too early. If you punch it at around 40 it backshifts to 3rd and just boogs. Prior to the tune I would say it backshifted to 2nd at that speed and broke the tires loose, now it just chuggs along. Any thoughts?

Whoever did the recalibration for your gears messed with your trans shift points as well.

Send it back and tell 'em to fix it.

- Justin

yeah sounds like a simple shift point issue.

Sounds somewhat familiar, doesn't it Bill?

- Justin

Actually this is probably a much easier fix since its only a bolt on car.

Didn't you have the same issue after one of your tunes from *that shop*?

- Justin

Completely different issue, sounds similar but really isn't.