BradyB

So I'm loving my Stage II kit, I picked up about 2 PSI over stock which means I'm running about 12 PSI now. Stock I was only running 10 PSI. Before you tell me there is something wrong with my car make sure you understand that I'm pretty high up here in Salt Lake. There is a lot less air to compress up here, cars run a full second slower in the 1/4 here compared to sea level.

So now I have the new two piece pulley which will really help with swapping pulleys. What size could I buy that would get me to 15PSI like the stage II cars at sea level? Of course I'm assuming the stage II cars are running 15 PSI. And if I did add a smaller pulley will I get belt slip even though I'm using the smaller stage II belt?

Serpico

you can run up to 2.7 (from ZZP) without maching the hub.....id go with the 2.7

Chevypowered

15 psi might take a mighty small pulley. I had my SS/SC at 6,500 feet in NM and with a 2.7 i saw 12.5 psi on the interceptor, the DV would only some times release the pressure. When i went to Albuquerque at 5,200' i saw about 13.5-14. I would guess at 4,500' it would take a 2.7 or even 2.6 to achieve your 15 psi.

You need to get the smaller belt and possibly a different idler arm or idler pulley.

With this set up you will run hotter AIT's so an upgraded heat exchange would be great to go with it to help keep that psi up.

BradyB

I'll probaby just stick with the stage II then If I can't just swap a pulley without worrying about finding another belt or the idler arm or pulley.

Now Chevypowered,
Wouldn't the intake temps be the similar per PSI? Intake temps are going to increase with air density. So if you have a stage II car running in Cali with 15 PSI and I'm running 15 PSI up here in UT, my intake temps aren't going to be much higher right?

Has anyone swapped in a bigger Eaton, like a Grand Prix S/C for more volume and lower intake temps?

I miss my turbo, the waste gate always opened up at the same PSI but sometimes it just took longer.

Chevypowered

You also have to consider heat being created fromt the speed the supercharger is turning with that pulley. My temps went up more quickly and stayed higher when driving around compared to stock where i was only making 6.5 psi, i can almost guaranty that my car was running hotter a 12.5 psi with a 2.7 than one at sea level was with the stock pulley. The S/C has to work alot harder to get that psi with a smaller pulley.

BradyB

So for any PSI increase that would only require a different pulley and nothing else, what am I looking at?

Just a 2.8? What size is the stage II pulley?

Chevypowered

Thats all you need, i believe the Stage 2 is a 3" or 2.9" pulley, i would go for a 2.7 if you can get it, but the 2.8" will work too. If i were you i would also get a intercepter guage so you can acuratly see your psi, my stock guage read 10 when i was getting 6.5. I would also get the car dyno once you get a smaller pulley so you can see your AFR

StinkBOMB

Stage II is a 3" pulley.

BLKSS

3.077... is stock stage 2

you can go down to a 2.7 on stage 2 belt. Any smaller you will slip.