Paul,
Either is a great setup. Wanted to try a roots type blower. One thing to consider is a paxton will fit under the hood. I will follow Joe’s lead and cut a flat hood for my 69 Cobra Jet style hood scoop.
The basic difference between a paxton and a roots type is a paxton is not a “positive displacement” blower. The Whipple, Weiand, Eaton, and Dyer (old “jimi”) 471/671/871 are positive displacement style blowers. A turbo and a paxton are not.
The simple description of a roots style is it is not blow through. Once the air is captured by the rotors inside a roots style blower it is “forced” and cannot go back up out of the top, so to speak. If you take a paxton or a turbo and cover the outlet it will just spin and so to speak do nothing. That is why you see “blow out” plates on the roots style blowers. That is why you see straps on top fuel blowers to keep them from landing in your lap in the stands. Once the rotors capture the air it must go out the other side until it stops turning. They have Teflon seals on the rotor tips.
Now the basic difference in performance. The positive displacement blower will develop more horsepower and torque at low rpm’s. The dreaded supercharger “lag” you here about. But I will tell you that proper tuning and so on has reduced this gap a quite a bit. Either system will add huge power. Turbos seem to have the most lag. But I am sure someone would attack me on that one! Tuning tuning tuning.
Most, if not all, of the new cars have went to roots style blowers. They are just as dependable if not more. Proper air cleaners are a must. My brother has a 92 Ford Thunderbird Super Coupe. Eaton blower. Huge low end torque increase.
I would stay away from the old Paxton supercharger with the “drive ball” style internals. I lost the ball bearings in mine and rebuilt it with very little miles on it. The new Paxton/Novi is a gear driven style and much stronger and more dependable.
Either system will put a big smile on your face!!
Rob