How much boost does an overdrive crank add?

[SteveP]

With my stock crank and a 2.85 i was at 15lbs. When I added the 10% crank and upped the blower pulley to a 3" (due to over spinning the blower with the 2.85) Im up to 17lbs now. I also boost right away now which is awesome!

 

[KrisR]

In the example I listed, my friend's car also still has stock 2V heads and cams, with a Bullitt intake, so it's possible that the increased blower speed just created more boost stacking in the intake, as it didn't really pick up that much power from the increased boost (from ~420rwhp to ~450rwhp if I remember correctly).

Also, the higher you rev each combo, the more boost you will gain from the big crank pulley when using a centri. Example, if you shift at 6000rpm and have 12psi of boost then, you might go to 14psi with the bigger crank pulley, a 2psi increase. If you spin it to 7000rpm and see 15psi before, you might see 19psi after.

 

[Alter Ego Trip]

I also boost right away now which is awesome!

This is my whole reason for the switch. I'm trying to limit overall boost while increasing how quick it comes on in the rev range.

 

[1MEANSALEEN]

With my stock crank and a 2.85 i was at 15lbs. When I added the 10% crank and upped the blower pulley to a 3" (due to over spinning the blower with the 2.85) Im up to 17lbs now. I also boost right away now which is awesome!

what blower do you have?

 

[bmaxwell]

Bringing this back from the dead! (was researching about 10% OD pulleys) Would a 10% with a 2.75 on a saleen just be retarded?? I was thinkin about doing that but sounds like the supercharger may get overspun. Maybe a little bit bigger pulley like a 2.87 with the 10%? I am tryin to hit like 600whp