References to Ricardo's car making monstrous torque is simply misleading. I really hate even getting into these arguments because the data is so completely flawed that no conclusions can be drawn.
Ricardo's car had, at the time, a mild cam specifically designed to have great low end response since he insisted that the car "respond at 1800rpm". Yes, his cam was designed to do that. Then, he added Rhoads lifters which decrease low rpm duration even more which further enhanced low rpm cylinder pressure. Then, he insisted on overdriving the M112 by 15% creating ridiculous amounts of boost at low rpm. By higher rpms the blower seemed to be "out of breath" as boost actually fell off slightly and power was down significantly due to extreme heat. I told Ricardo at the time I didn't think the combination was anything close to safe or reasonable and I still hold to that opinion.
Then later, he ditched the Rhoads lifters and went up significantly in cam duration which killed his bottom end regardless of what blower it may or may not have had. That he didn't run the car that way with the M112 is irrelevant. It wouldn't have made torque numbers anywhere close to what it did with the other cam and lifters, but that point is mute anymore since he has the AR on it now.
As for a twin screw, you have to look at blower rpm and compressor efficiency. At very low rpms the power consumption is higher and the VE lower on the big twin screws. The 1.7 will come "up on its map" sooner and will make 19psi on most motors without breaking a sweat all the way to 6200rpm. That's where mine made peak power and it was at 19psi. Look at the dyno chart to see what I mean. At that point I don't think you'd see a significant difference between the 1.7 and a 2.3.
Now if you drive the supercharger faster and take it higher, things start to get different. But, 99% of all SC motors aren't the slightest bit efficient above 6000rpm anyway, so again, the point is mute. Who cares which SC is most efficient when you are so far out of the engine's operating range that the motor isn't making power anyway?
There are about 4 SC engines out there that have the ability to rev beyond 6200rpm without getting into various forms of valve float. Just something to ponder.
As for Whipple's claims of a more efficient blower, they are really splitting hairs to justify their higher prices. It's like a cylinder head that flows 230cfm vs on that flows 220cfm. SC people will go nuts for the extra 10cfm but then scratch their heads when a 190cfm head waxes them at the track. Too much emphasis on the wrong things. Not that flow isn't important, but it's just one aspect in the overall package.
at the same rpm what would you beleive their HP diffrence would be?
