Yes it does. I was making 10psi with the whipple on a stock 6.0. Now with the new setup, it only makes 7psi. Looks like this engine is alot more effecient at getting the air in and out. I allready have whipples smallest pulley, so I guess it's time to get a custom one made. :)

Yes it does. I was making 10psi with the whipple on a stock 6.0. Now with the new setup, it only makes 7psi. Looks like this engine is alot more effecient at getting the air in and out. I allready have whipples smallest pulley, so I guess it's time to get a custom one made. :)

Yip, efficiency is good stuff. Your still stuffing the same volume of air through it, it's just flowing better. Hence where the power increase will come from, now stuff a 9.75" crank pulley on it and get the pressure back :devil:

Yip, efficiency is good stuff. Your still stuffing the same volume of air through it, it's just flowing better. Hence where the power increase will come from, now stuff a 9.75" crank pulley on it and get the pressure back :devil:



where does one purchase a 9.75" crank pulley?

where does one purchase a 9.75" crank pulley?
I dont think anyone makes a bigger crank pulley for us gm guys. Leater had ASP custom make him a crank pulley for his.

I dont think anyone makes a bigger crank pulley for us gm guys. Leater had ASP custom make him a crank pulley for his.
let me know if you go that route. Maybe we could get a GP going and get a discount. Im very serious about this so shoot me a PM when you get info please.
Refresh my memory... what are the negatives of a larger crank pulley??

let me know if you go that route. Maybe we could get a GP going and get a discount. Im very serious about this so shoot me a PM when you get info please.
Refresh my memory... what are the negatives of a larger crank pulley??

I'm not sure about you GM guys, but as stated someone like ASP can make most anything you want.

As for the negatives it depends on the SC setup. If it's a single belt system, where the SD is driven off the same drive belt as all the accessories then going to a larger crank pulley will overdrive everything. At this time it would probably be a good idea to toss on some underdrive alt, waterpump, and ps pulleys if they are available.

I had a guy bragging to me that he picked up 2 lbs of boost with his new high flow cat back system :jest: :jest: I almost pissed my pants I was laughing so hard :jest: Oh ya I want one of those systems! :jest: :jest:NOT!

I'm not sure about you GM guys, but as stated someone like ASP can make most anything you want.

As for the negatives it depends on the SC setup. If it's a single belt system, where the SD is driven off the same drive belt as all the accessories then going to a larger crank pulley will overdrive everything. At this time it would probably be a good idea to toss on some underdrive alt, waterpump, and ps pulleys if they are available.
That sounds about right. :( I guess I'll be sticking to the stock crank pulley. I wish I had gone Turbo :bang:

That sounds about right. :( I guess I'll be sticking to the stock crank pulley. I wish I had gone Turbo :bang:
yeah then you could just turn up the boost lol

I had a guy bragging to me that he picked up 2 lbs of boost with his new high flow cat back system :jest: :jest: I almost pissed my pants I was laughing so hard :jest: Oh ya I want one of those systems! :jest: :jest:NOT!

thats funny stuff :jest: :jest:

Too much overlap on a cam can bleed off boost out the exhaust too. That's about the only thing that could be contributing negatively to boost levels.

right now we have a 6 rib drive system.
how about a 8 rib drive system for more grip, same size crank pulley 8 rib, alt pulley 8 rib, and a supercharger pulley 8 rib. idlers i can get from the auto parts store that is made for the 8 rib belt.

Swap out all the pulley's? Can anyone promise no slippage? 'Cuz I'll buy that for a dollar!

Otherwise; how far did you go w/your ehaust or TB? Our sensors aren't easily fooled...

A bigger crank pulley would be good since you get more belt wrap.

Randy, i have a alt pulley from my asp underdrive set if you need/want it. not sure if it would help you at all if you ever got a larger crank pulley.

What about planed heads and raising compression? I know it won't raise boost but would it compensate?
What'd you do to the heads?