PSI b,c,d ID

Anybody know how to tell a B C or D rotor apart by looking at them? Looking at one with no numbers on it. What year was the C rotor started? Did they make any other models?
Thanks Mike

 

Do a search and there is a thread in the archives where Roger from PSI answered some of the questions you are asking. Here is part of what he said. I do know on the early models there is no gap in the front of the blower to the rotors. That would be all 200 series and the B series for gas.

There has been a few questions about how a PSI "C" and "D" compare so here it is in overdrive a "D" at 125% would be approximately the same as a "C" at 104% so just over 10% 2.25/2.04 = 1.102 - 1 = 10.2%

The last question that comes to mind is how to tell the difference between a "D" and a "C" measure the female or driven rotor lobe thickness, there are small variation based on application and date of manufacture or customers specific needs but on average a "C" will measure .483-.485 a "D" will measure .594-.596 both blowers have a open port in the housing between the front shaft/bearing supports.

 

psi

Thanks, that covers it.

 

How would the old 200 series rate in performance compared to the 206 series ?

 

PSI and Whipple CID/Rev

The pumping displacement (in cubic inches per revolution) for the Screw blowers is about:

PSI 200-A = 385 cid/rev (200 mm diameter of the male rotor)
PSI 206-B = 422 cid/rev
PSI 210-C = 476 cid/rev
PSI 206-D = 422 cid/rev

Whipple A980 = 601 cid/rev (9.80 liters per rev)
Whipple R980 = 601 cid/rev
Whipple 305R = 305 cid/rev

By way of comparison, a 14-71 Roots = 551 cid/rev

Patrick Hale
www.DragRacingPro.com

 

What is the difference between the B and the D series if they both have the same amount of cid/rev? Are the placement of the hat nozzles different?

 

The PSI 206-B supercharger is intended for gasoline fueled applications, primarily marine. So it is designed to operate in a much hotter enviroment for longer periods of time than 5 second methanol drag racing engines. The PSI 206-B is also not SFI certified.

Patrick Hale
www.DragRacingPro.com

 

I have a PSI 200A...what overdrive should I use to get around 30psi on a conventional headed BBC 540 at 8000rpm ? Can this blower provide the air needed to make this boost ? Not much info out there on the 200A...too old and outdated I guess.

 

125% over ? Do I dare spin this blower faster ?

 

so i run a top alcohol hydro i have a d rotor on it would i get the same peformance out of it if i bought a b as a backup blower?
thanks
james
p.s what about a 200 c blower

 

Call out to PSI and talk to Roger or Norm. They should be able to get you pointed in the right direction.

 

not sure if the rotors are the same, I know the front opening is not as open (large) on a B as a D- in front of the rotors.
no burst panel on a B either but appears you could open it up for one