BlownAlaskan

iTrader: (3)

So, this may be a dumb thought, but has anyone ever tried it before?

At first thought it kind of makes sense to be able to spin the blower faster at lower rpms through a smaller pulley, and to then let off some of the excess boost in the upper RPM's.

For example: the max impleller rpm for a p1sc or d1sc is 62-65K rpm, does anyone know what the optimum efficiency point is, if one exists?

Black Blown 02

The only problem with blowing off excess boost at high rpm is, the blower still has to do the work to make all that boost. Then if you don't shove it into the engine, you still lose the extra parasitic hp that the blower takes to run. Plus, the extra heat created from spinning the blower faster reduces hp also.

This has been discussed before in the forced induction forum. One of the smart guys in there said the only way to do it efficiently is to pulley for extra boost, and choke down the air inlet to the blower so at xx amount of airflow, it won't make any more boost. That makes a little more sense to me. Still don't know all the variables that would come into play though.

ATI won't release any compressor maps for their blowers. So nobody knows any efficiency numbers.

I thought about doing this for a while. Then I got my big stall. You don't need to worry as much about low rpm boost with a good sized stall.

BlownAlaskan

iTrader: (3)

This foils my plan. Why wouldn't ATI post the info....?

Black Blown 02

I don't know, kinda makes me think their efficiency sucks or something. All the F-bod guys that can stop the belt from slipping seem to make good numbers though.

BlownAlaskan

iTrader: (3)

I know they do. Thats why I got to thinking we just need to spin ours a little faster. 2 days till I get home, almost time to play!

Tom told me like less than 3 weeks on the intercooler, I was expecting longer. You still convinced about yours??

Black Blown 02

Yeah, you may change your mind about spinning it faster when you get that intercooler on.

BlownAlaskan

iTrader: (3)

I hope so.. that will be great to get a few more degrees of advance. I was just looking at those RR pulleys. I need to get one of thoses too. Ever find a 110 incher? If not, I'm gonna have to step back up to a larger pulley I think.

Black Blown 02

Never found a 110. I don't think anyone makes one. If I go to a 3.4", I think I'll just try the 110.5 with it.