(Crank pulley diameter/Blower pulley diameter)*Engine rpm

 

it was ranwalk that made 500hp with a whipple. just remembered

 

Most people will tell you that the max blower rpm is about 20,000 rpm. It is only efficent to about 14,000 though. After that it starts to super heat the air, 300+ degrees and your power will really fall off. I was running a 7.75 crank pulley with a 2.5 supercharger pulley for 17,980 rpm at 5800 rpm. If you could keep the belt from slipping it would make 7 lbs, but after 1 dyno run it would loose 40 hp due to heat soak.

 

Thanks. I think my MAP sensor is bad. I ran it today with a handheld vacuum/boost gauge, and it showed about 7 psi. After I get that sorted out, I probably will see if they make a 2 3/8" pulley and try to explode this blower. I am hoping that my big-assed intercooler will do what I bought it to do.

 

How about adding a single turbo before the Whipple? It would feed your need at high end.
Like this set-up.

https://www.performancetrucks.net/fo...d.php?t=407498

 

Well, I haven't been able to do much since we are having an actual winter in Chicago instead of the super-warm ones of the recent past. What I have learned is it really is making only 5 psi boost, my inline pump went bad, and I can't stand the stink from my crankcase fumes anymore.
>The inline pump sounds like a siren, and the motor goes lean after 4000. My gauge that I taped on the outside of the windshield to test with showed a drop, but couldn't react fast enough because I won't keep the throttle mashed until I melt a piston. I added a 3-wire pressure sensor and tied in to HP Tuners, pressure dropped to as low as 34 (from 62) psi. The sensor that I installed is from an HVAC controls-supply house.
>I am going to put PCV back into operation. After studying in my service manual how it actually, works, I came up with an idea. The book says that the valve will close under high vacuum situations to maintain idle quality. "If abnormal operating conditions arise, the system is designed to allow excessive amounts of blowby gases to back flow through the crankcase vent tube into the engine air inlet to be consumed by normal combustion." The engine air inlet is the tube on the throttle body. Knowing this, I think my idea might work to keep oil out of the intake, and off of everything in the engine compartment. Mine spits oil because we had to take the valve cover baffles out to clear the Comp Cams roller rockers.
>For a detailed description of my idea, mail $10.00 to me and... just kidding. I am going to run the hose from the PCV valve through a catch can, to a fitting that I will tap into the vacuum side of the supercharger, eliminating the problem of the stock setup pressurizing and closing the valve under boost. The vent tube, since it flows fumes in both directions, will have a seperate catch can, and then go to the engine air inlet. I always assumed this was a vacuum fitting, but it is just a place for the vent tube to pick up filtered air, or dump extra fumes upsteam of the throttle. Of all the threads that I've read about PCV, I don't remember a setup exactly like this. Or maybe, because I finally understand PCV, 41 years after its introduction, I wasn't understanding your guy's boosted PCV setups.

 

I agree with the "Not enough S/C for the engine", theory too. I know i can only make about 6 lbs max with my set up.....sometimes i see about 7lbs in the winter. I used a 2-3/4", a 2-5/8", and a 2-1/2" pulley and they all made the exact same boost at WOT. So naturally i put the 2-3/4" back on to get the lowest IAT's i could for the given boost level. I think thats the 2-5/8" pulley on there in my signature.

I have sent several Emails over to Mike and Jeff at whipple asking if they make an upgrade kit so i can bolt up the 3.3l whipple but have not received a reply yet. I am pretty sure the 3.3l is too long and would extend past my plumb line for the pulleys and/or would let the throttle body hit the fire wall.