Supercharger crank pulley ??

[tunedin302]

Considering going to a larger crank pulley to yield some more boost. Vortech lists two pulleys:
1) 6.87 sc pulley w/ a 6" accessory drive
2) 6.87 sc pulley w/ a 4.5 accessory drive
Anyone have experience with these? I thought vortech had a 8" crank pulley at one time. Thanks.

 

[blackcloud50]

Considering going to a larger crank pulley to yield some more boost. Vortech lists two pulleys:
1) 6.87 sc pulley w/ a 6" accessory drive
2) 6.87 sc pulley w/ a 4.5 accessory drive
Anyone have experience with these? I thought vortech had a 8" crank pulley at one time. Thanks.

They do. 8" w/ a 4.75 accessory drive. It's for 8 rib setup.
part # 4FA018-029

 

[Rick 91GT]

Check out http://www.aspracing.com/frame.htm as well, if you want a Vortech pulley let me know, I'll get you a good price.

We ran the 7", 6 rib on dads old A-trim combo, nice pulley, all aluminum, underdrive crank, picked upa few pounds of boost.

 

[just4bob50]

I run the 7" under/over crank pulley and with 6lb pulley on the charger I was seeing almost 8lbs of boost at 6000rpms on my factory tach. Then I had a 9lb pulley put on and I was seeing 10-11 lbs at the same rpms. From a 6" crank pulley, the 7" would be a 15% increase. I actually ordered the 8" puilley first but it made contact with the factory water pump pulley when the belt was on. If you want to run the 8" pulley I think you will need to get a smaller water pump pulley,and change the charger pulley to 8 rib as well.

 

[RacEoHolic330]

It is kind of a pain to install an 8" crank pulley because you do need to install a 93 cobra water pump pulley as well. I think its worth it though. I'm running a 10-rib 3.33/8" setup and I'm seeing 14lbs of boost at 5800 rpm. This is compared to the 10lbs I was seeing with my 3.33/6.87" combo. The boost also comes on a lot sooner.

 

[blackcloud50]

It is kind of a pain to install an 8" crank pulley because you do need to install a 93 cobra water pump pulley as well. I think its worth it though. I'm running a 10-rib 3.33/8" setup and I'm seeing 14lbs of boost at 5800 rpm. This is compared to the 10lbs I was seeing with my 3.33/6.87" combo. The boost also comes on a lot sooner.

I see 14 psi with stock pulley configuraion (3.33/6.87) and AFM powerpipe. While at the same time not underdriving any accessories.