Changing overdrive on my screw blower and have a couple of ?'s

I am currently running a KB Olds with 12 degree RFE wedge heads, with a PSI "C" Rotor Screw Blower. Right now the blower is at 91% over, I want to step up to 100% over. The current compression is 10.7to1 but i'm dropping it down to 10.35to1 to compensate for the increased boost. Here's my ?'s. How much more boost will the engine have at 9000rpm?? And how much of a "true" power increase will I see in going up 9%? Assuming I adjust the fuel tuneup correctly for the increased overdrive.

Right now the blower makes 51lbs of boost at 9000rpm in high gear!!
Thanks. Lonnie

 

Why reduce the compression and then turn up the blower? I dont see the reasoning in that.

 

Lonnie's on the right track. Taking compression out lessens the possibilty of hurting the engine. The engine is much happier with less compression. YOur tuning window gets much bigger. Besides, you can make up for compression with boost.

 

Thats why i'm taking compression out. We blew both head gaskets out last time we ran. I need to take a good amount of compression out. Plus I was told by Walt Austin to do it, and it will be a more powerfull, happy creature.

 

Lonnie, do yourself a favor. Find a Detroit Diesel dealer and go to the parts department and get some International Compound #2, otherwise known as peanut butter. Put it on the head stud, both sides of the washer and the underside of the nuts. You should get 1/4 to 1/2 turn more on the nuts.

 

Tony, Do I torque the head studs to the same torque as i did with moly?

 

Post of the day.

 

Same torque setting Lonnie.

 

You should see it all because the PSI is right in it's most efficient range around there - BUT..... it will be a 4.5% increase.
You are going from 191% over engine speed to 200% - hence 4.5%.

 

200
-191
=9% at least when i went to school
unless your spinning this with the camshaft

 

191 + 4.5% = 200. Trust me.
200 - 191 is not calculating the percentage. 200/191 will give you a percentage figure.

 

OR 191 divided by 200 equals .955 OR a change of .045 (4.5%)
Keith