SUPERCHARGER!

[Fierobsessed]

Im a sucker for SC vs TC debait's

Roots are great 0-35MPH. To me that's just a cheap thrill. Over 4000 RPM they fall flat on their face.

I STRONGLY dissagree with that notion. Everytime you shift with a Supercharger the power is still 100% there. I shift out of first at 35. So wheres the cheep thrill in that. It starts out holy shit fast, and just keeps going. The "falls flat on their face" comment is totally off base. The Roots blower flows air in a linear fashon and does so from a few RPM's all the way to the point where the unit explodes. Its just a matter of how much heat they produce. Like I stated before, I don't even expect the blower to ever go beyond 14,000 RPM's so the heat will be managable. The water injection system will come in handy. There is a common misconseption that since turbos use exhaust that they use "free power". The back pressure that turbo engines have to endure is staggering. I don't know the exact figures, but its shure as heck is more then the amount of boost they push. This causes hot, burnt gas to get trapped in the cylender to some extent. Not to mension that The turbocharger is really being spun by your piston pushing out hot gas when the exhaust valve opens. So it STILL takes alot of power to make power. Somewhere I read that the efficiency of a turbo is somewhere around 80%. A standard Roots blower is about 70% efficient. (Eatons are close to 80%!!) Mostly the inneficiencies are due to the drive system and the weight of spinning the two rotors at high rates of speed, around twice crank speed usually. The rest is in friction of air to the rotors. Eaton SC's are the most efficient Roots blowers on the market, They are actually really close to the efficiency of a turbo. At least thats what I know from what I have read. Also, OEM superchargers AND turbochargers are designed to last 100,000 miles. The supercharger is designed to NEVER need an oil change. Turbocharged engines need only routine ENGINE maintenence to survive. So reliability is not an issue with either, However both can fail if they are deliberatly exceeding there design limits. So in the end, neither are better, both are great! But depending on the application one will outshine the other. Thats the end of my status on that debait.

[grandprixgtp_91]

oh man, i took my M90 out to my shop today and i took out my impact gun and put a 18mm socket on it and spun the pulley on the M90 and man does it sound cool when it starts to spin up. i put my hand over it and it was blowing alot of air, and i dont think that impact gun does more than 1000 rpm. so i know the supercharger works good! now i really cant wait to finish my prix! the only thing is though is after about 30 seconds of having the M90 running at a constant speed it started blowing out warm air! so i am gonna definatly need an intercooler.

Jake

[pocket-rocket]

I think this discussion is starting to sound more like EFI Street, so therefore I am unsubscribing from this thread...