87irocz350

I have a 87 iroc with a 350 tpi with a t5 3.42.
My shift light went out on the car before I got it.
For good gas mileage I usally shift around 2,500 rpm.
When Im racing I shift at 4,000 rpm.
Are these good shift points or do I need to use new one.
Please post what you guys do.

AlkyIROC

Shift points depend on where your engine's powerband is. A TPI engine doesn't pull much above 5500 rpm. Keep trying higher shift points to find the best one. I would say 4800-5200 would be a better range.

A perfect driveline combination is shifting a couple of hundred rpm above the engine's peak HP and going across the finish line a couple of hundred rpm above the shift point.

Mark A Shields

Actually I thought TPI's stop breating at 4500 rpms??

Though with the steep 1st gear, I would say shifting @5k would be ok for the 1-2 shift, then 4500 rpms on the 2-3. Just experiment and find out what's best. That's why I find the G-Tech a very useful tool.

91_350TPI

I did some experimenting with my 91 350 GTA and found that the best shift points for my car was 4700 1-2 and 4500 2-D. Something I was unable to try though, and I think it may have made a difference, was shifting 2-D at around 4200 - 4300. I tried making both shifts at 5000 first and then went to 5000 and 4800 and improved. Then went to 4700 and 4700 and improved a little more and finally went to 4700 and 4500 and improved yet a little more. The only reason I couldn't try bringing the 2-D shift down more is that the car automatically shifts at 4500 whether I shift it early or not. I bet it would help the car though. Hope I helped a little. Drive on...Damien