Shift points and lock up

After I do some basic maintenance including the steering tsb which is annoying the s^$! out of me lol, I will raise the part throttle shift points & lock up. My buddy has hp tuners so I will buy another $100 credit. He tweaked my 99 trans am where we raised 2-3 3-4 about 10 mph and the lock up between 54-62 mph, it made a big difference. Can anybody add any experience? I am also about to do belts since the car is 20 years old. Is there a pulley that will make low ned seat of pants difference w/o dealing with kr and plugs ect? Brian.

carguy8888 wrote:

After I do some basic maintenance including the steering tsb which is annoying the s^$! out of me lol, I will raise the part throttle shift points & lock up. My buddy has hp tuners so I will buy another $100 credit. He tweaked my 99 trans am where we raised 2-3 3-4 about 10 mph and the lock up between 54-62 mph, it made a big difference. Can anybody add any experience? I am also about to do belts since the car is 20 years old. Is there a pulley that will make low ned seat of pants difference w/o dealing with kr and plugs ect? Brian.

If the drivetrain is otherwise perfect I am told you can drop the pulley 2/10" without other mods and not create crazy KR. In practical terms that means getting a pulley off a Series I supercharged engine (there are lots and lots around).

Thanks Albert, will I feel a difference and does the belt size change?

The series 1 S/C has a 2.8” diameter pulley. The series 2 has a 3.8” pulley. I think Albert was thinking the S1 pulley was bigger. You can usually drop a few tenths safely, like he mentioned. Most people will start with a drop to 3.6” pulley on the Series 2 without major mods. If the car has no issues, you will probably never experience any issues. You should feel a noticable difference, especially with a tune. And no, the belt size will not change for that small of a pulley drop.

Awesome, thank you both.

th3fr4nchi5e wrote:

The series 1 S/C has a 2.8” diameter pulley. The series 2 has a 3.8” pulley. I think Albert was thinking the S1 pulley was bigger. You can usually drop a few tenths safely, like he mentioned. Most people will start with a drop to 3.6” pulley on the Series 2 without major mods. If the car has no issues, you will probably never experience any issues. You should feel a noticable difference, especially with a tune. And no, the belt size will not change for that small of a pulley drop.

You are right Dave, I had in my notes the S1 pulley was 3.4" so thank you for correcting me.

Yes if the car has no other drivetrain (ignition/fuel/engine mechanical/transmission) issues your butt dyno will feel the difference with the small pulley drop. Part of the reason for that is the vac cutoff still works and the computer parameters didn't change. So boost comes on a bit quicker and holds a bit harder but that's about it. It is discernible.

Older posts on this site go into much detail about mods, and I would heed those posts and not me. None of that stuff has changed.