8.5 lower with 3" upper = 2.833
10 lower with 3.5 upper = 2.857

the pulley ratios are very close not even enougth for a 1/4 of a pound of boost

 

Can you post the graphs?

I could honestly care les about PEAK HP, I'm more concerned with, which one has more "space" under the graph.

 

At 5500 engine rpm the Whipple is spinning 15565 rpm.

At 5500 engine rpm the KB is spinning 15675 rpm.

So the KB was spinning 110 rpm faster. That's pretty close.

Thanks for the info Ronnie.

Looks like it's all in the plenum for the KB. Use the C&L and get more lower rpm torque with less peak HP. Use the JL plenum to make it respond on the same curve as the Whipple.

Edit: I rounded down to 2.83 and 2.85 on the ratios so for all you **** retentive math wizards out there add 21 rpm to the 110.

 

Thanks for the test results, Ronnie!

I'm only concerned with boost vs. boost, not pulley size. Makes me glad I just bought a KB.

 

Did I read correctly this was done on two different dyno's?

 

No..

 

Same dyno. Sorry for any confusion.

 

I think with the KB with the JLP Plenum, the Whipple makes about two more PSI with the same pulley combo. We'll see what happens when we do the 21 pounds of boost test.

 

Thanks for the info!
Thanks NC for the test. Look forward to seeing a little higher boost numbers.
I run right about that boost level at the track. -Mat-

 

put the 10lb on their and then lets see if it will be close. The whipple is making almost the same power with atleast 6 less pounds of boost, it doesn't seem fair to say that the whipple and kennybell were so close. Don't get me wrong i'll give my left nut for a kenny bell , but the whipple is in a class of its own.

 

Actually the boost was the same @ 15psi.

 

At 5500 engine rpm the Whipple is spinning 15565 rpm.

At 5500 engine rpm the KB is spinning 15675 rpm.

So the KB was spinning 110 rpm faster. That's pretty close.

Thanks for the info Ronnie.

Looks like it's all in the plenum for the KB. Use the C&L and get more lower rpm torque with less peak HP. Use the JL plenum to make it respond on the same curve as the Whipple.

Edit: I rounded down to 2.83 and 2.85 on the ratios so for all you **** retentive math wizards out there add 21 rpm to the 110.

Looks Like the ratio's are very close..15# is 15# just like 21# will be 21# when you turn it up!..As far as the KB being out of steam @ 15# No way! i have personally seen 30# on that same KB!
What everybody is failing to see is that the whipple isn't making no where the power over the KB those claimed it would! i heard 50 more HP! @ the same boost levels! If that were true i would have had 1 a long time ago on my truck! JL

 

What are you talking about... This was a test of equal psi vs equal psi.. It doesn't matter what pulleys get you there...

All this proves is that the Whipple will make high boost with less blower RPM... Some people just don't get it...

The whipple will out perform in the 20+ psi because of it's better efficiency, but most of us won't spin it over 20 psi, so it doesn't matter what pulley combos get you there...

This shows that in the range that 90% of us will be with when we order a twin screw they are equal...

 

It looks like some people are already figuring this out but....if you learn how to "feed" the KB properly....it will run heads up with a whipple in the upper boost ranges. My KB made 23 lbs of boost with an 8 lb lower and a 2.7 upper and a lot of mods to the intake manifold/spacer side of the blower and also the air cleaner arangement.
Dale

 

i plan on boosting over 20psi.. which is why i made my purchase for a Whipple when i did...