Who read about this comparison in the latest MM&FF?
It sounds like a number of you hard core HP junkies might be switching the the Kenne Bell blower when it comes out. The autorotor was much more effiecent, made more boost at the same rotor speed, and had significantly cooler temps coming out of the SC and the intercooler.
The tests were done on a 4.6 2V w/ a M90 and 1.5L Autorotor.
What do you guys think?
Ohh yeah, if you need numbers because you didn't get the mag, just say so and I'll make a post that will have specifics.

 

Numbers Please!

Is there a website for this "Autorotor"?

 

What's the max displacement on an autorotor?

Our Eaton 112 are a far cry from the M90 used on the supercoupe.

 

From the article:
"...using the same 2.75" blower pulleys. Both the 3150 Autorotor and M90 eaton are positive displacement superchargers, displace nearly 1.5 liters and are used in it form on 4.6 V8's. What better measure of performance then to run the two blowers at the same rotor speed? Spinning the two blowers at the same speed clearly demonstarted the superiority of the twin-screw design. Running an identicle blower speed, the Autorotor produced 47 more peak HP than the Eaton...."

M90 Eaton: 2.75" blower pulley
Max Boost - 7.7
Inlet air temp - 77
Air into Intercooler - 185
Air out of Intercooler - 162
Rotor Speed - 14,180
Peak HP - 287

3150 Autorotor (Twin Screw): 2.75" blower pulley
Max Boost - 10
Inlet air temp - 75
Air into Intercooler - 190
Air out of Intercooler - 140
Rotor Speed - 14,180
Peak HP - 331

"...what happended when we installed the 1.975 pulley on both superchargers. The Eaton had long since run out of flow potential, topping out at 317 hp. The Autorotor produced a whopping 388 hp using the same pulley ratio for a gain of 72 hp. Measured at 6000rpm, the difference between the two superchargers was nearly 100 hp! While the Eaton was indeed done in terms of power out, we installed a larger throttle body and MAF to feed the Autorotor and managed to up the power even more to 419 HP. the throttle body and larger MAF had no effect on the Eaton."

M90 Eaton: 1.975" blower pulley
Max Boost - 12.6
Inlet air temp - 76
Air into Intercooler - 304
Air out of Intercooler - 233
Rotor Speed - 19,746
Peak HP - 318

3150 Autorotor (Twin Screw): 1.975" blower pulley
Max Boost - 15.7
Inlet air temp - 74
Air into Intercooler - 260
Air out of Intercooler - 173
Rotor Speed - 19,746
Peak HP - 388


OK, hope this helps. I can't type the "whole" artilce, lol. Ohh, Kenne Bell uses the Autorotor (twin screw) in his kits. And he has a 2.2L Blowzilla that would be closer to the M112. I am assuming thats what he would use in his Lightning kits.

 

Did they use the same intercooler for both set-ups? The temperature drops don't seem to match up.

It looks like the Autorotor had a better intercooler.

 

I was real disappointed in MM+FF in letting Kenne Bell run the show on all this info. Kenne Bell sells autorotor kits only so he is real biased in his testing. All negatives of the eaton were exploited and all positives were disregarded. The autorotor is more efficient period, BUT it has some negatives: It has no built in bypass valve so if they had done a part throttle temp run you would have seen a big difference in temps with the autorotor being much worse. This is important says after driving awhile and then flooring it, it may detonate initially. Also even though they have the same size case they don't flow the same, they are different designs similar to centrifugal superchargers just because you put the same size pulley on those they have different pitches on the impellers and so forth. If you will note when the blowers were run at the same psi the eaton did better down low and was promply disregarded and excuses were made for the aotorotor. If they had been fair they would have gone to bigger eaton also in the test. I also noticed that the in and out temps on the autorotor were much better than on the eaton this should throw a flag that this test was biased toward the autorotor. Kenne Bell is not below somewhat cheating to help his bottom dollar. ie:selling autorotor superchargers. Again apples to apples the autorotor is more efficient but if properly sized superchargers are used the difference is slight.

 

Screw that, (no pun intended). If I'm going to buy a new blower it better pump out more then 15 pounds of boost!

Think about it guys, Buy a novi 2000 blower kit for the f150's. take off the eaton blower all together and make a upper intake, which would be so easy with the interccoler being flat anyway. you could have a simple upper machined for next to nothing. Then pump out 30 pounds of boost and put both those blowers to shame. sure you have to rebuild the motor to handle that PSI, but you would have to with a Kenne bell blower anyway. on stock motors the eaton can make all the power you want!