Biggest, yet most practical street blower?

srothfuss said:
I'll refer to Dag's knowledge / experience but the Twin Screw shouldn't run out of any steam. The best part about the KB is that the boost is always on 100%. So there is no need to wait for the blower to spool up.... Meaning your leaving the guy next to you in the dust sooner. KB's website talks about shifting around 6,000 RPM but on the street, I can bet that is all you need.

actually the kb does run out of steam around the 57-5800 rpm range. there are some people who have run them as high as 60-6200 rpm. and over that there isnt anyone really. except for the 03-04 cobra guys. but if this is intended for a fox then thats it. like mentioned earlier the kb is a real good street blower and has 450-500 potential with a well planned out combo. anything over and even the 2.2 wont be any good without some kinda fabbed up intercooler. not trying to detur you if you're leaning that way, but it really depends on the individual. i went with the 2.2 and will hopefully have her together soon, my needs were different though. the car i'm building is a fat pig and i need all the torque to get her off the line. not doing any weight reduction. she is what she is. i had a 1.5 on the car first huffing into a stock 302 and it was fun for awhile but it left me wanting more. so bypass the 1.5 if you go the kb route and get the 2.2, you'll be glad you did. sorry for rambling.
 
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mark007 said:
actually the kb does run out of steam around the 57-5800 rpm range. there are some people who have run them as high as 60-6200 rpm. and over that there isnt anyone really. except for the 03-04 cobra guys. but if this is intended for a fox then thats it.

That is TOTALLY relative the pulley that you have mounted on the blower. The motor spinning at "57-5800 rpm range" has absolutely NOTHING to do with where the blower supposedly "runs out of steam". That term by the way could not be further form the truth. Every blower, regardless of type or configuration, has an efficiency range. That applies to centrifugals, turbos, Roots, screw type, whatever. Operate that device outside of it's efficency range and bad things start to happen. The 2.2L Kenne Bell Twin screw can make 500+ HP with the standard inlet. That rating jumps to roughly 650 with the larger Flowzilla inlet. Positive displacement blower are much more significantly effected by inlet restrictions than other types of forced induction. A Kenne Bell operating at the top of its efficiency range is able to make roughly 80 to 100+ MORE power just by opening op the pathway into the inlet. Saying that it "runs out of steam up top" is one of those silly things that's said over and over again with very little thought put into what's actaully happening. Take an N/A dyno from car X. Install a Kenne Bell on that car that's properly configured to support that combination. In effect, what happens is that you will "mirror" that N/A dyno but push the HP and Torque ratings further up the scale. So... If your combo previoulsy didn't continue to make power above 4500 RPM (for instance) then the same will apply after the twin screw has been added. That "out of steam" supposed scenario has a LOT more to do with the heads, cam, and rest of the combination than it does with the blower.

Centrigugal type blower tend to peak higher in the RPM range because of the sheer velocity of the air that's being forced into the induction system. The trade-off is heat (of course).

As for intercooling a KB on a 5oh. That's what water/meth injections is all about. :)