why do you guy's like a turbo vs a centrif Supcharger?

Guys, this is a great discussion and I think it's great that we can all come together to discuss 'preferences' with pros and cons of each configuration.

As a guy whose ran roots superchargers over the years, I can tell you the neck snapping throttle response is something you'll always appreciate, but roots style supercharges consume about 10% of your total HP to drive. A top fuel car uses about 800-1000 HP to drive a supercharger - to make 8000 HP and they are VERY hard on engine and driveline components.

However, at the end of the day, it's a fact that the most efficient means of pressurizing an engine is via turbo-charging. Even as roots supercharger have their...roots...in diesel powerplants, you'd be hard pressed to find a OTR truck mfg that doesn't employ a turbo to boost power and fuel efficiency.

Also, there is a reason turbos deliver "free" power:

As air enter the center of a turbocharger, that air is slung to outer most area of the turbo, where "centrifigual" force causes it to be compressed. This results in a higher volume of air being delivered to the engine. Not only is the air being compressed, but, because air has "weight", the turbo actually pumps more air volume per revolution than a naturally aspirated engine ever could.

So, in reality, it's the closest thing to free horsepower you can drive (i.e. the air volume on induction side of the turbo will always exceed the volume of air being used to drive it) versus frictional losses through a mechanical supercharger. In other words, it gives much more than it takes (in terms of HP) and the parasitic losses are almost zero.

Also, many of us witnessed this years ago; Guys like Gale Banks, Kenny Duttweiller, and a slew of others attempted to participate in Pro-Stock drag racing back in the 80's - with turbo-charged V6's. They were quickly outlawed from participating, and there was never an option for them to compete within their own division. You know why ?

Because, at a time when 500 cu.in. Pro Stockers were the rage of quarter mile fans, the turbo guys showed up with turbo charged 231 cu.in. V6's and handily out performed the best performing cars in the Pro Stock ranks - and you couldn't even hear them running down the track. The latter is also why you won't see them any time soon, as NHRA quickly outlawed them, claiming the fans won't be interested in "quiet" cars, and big noise sells tickets. I personally think it was an embarrassment to the NA guys, but who knows...

I watched this happen at Rockingham years ago, and after doing some research, found out Banks and other had plans to enter top fuel with twin turbos and compound setup, which would have not only been capable of annhialating the nitro crowd - but they would have done it while being low maintenance and easy on parts. They even built new rails in anticipation they would be accepted into the ranks, but to no avail. Again, NHRA stated they wouldn't be of interest to the fans and quickly banned them from Top Fuel, because fire and noise sells tickets ! Truth is, those cars would have quickly dominated the division and that would have had profound implications to racers and the vendors that cater to them.

Another good analogy is Indy racing. Those cars are limited to 200 cu.in. and make nearly 1000 HP - using turbos. They shift at ~ 16,000 to 18,000 rpms and they run well on the other side of 10,000 rpms for an entire race. The power to weight advantage of turbos has been exploited by Europeans for many decades now, and there hasn't been a positive displacement blower used in Indy since I can remember. Turbo technology is a well proven technology - in the right hands.

At the end of the day, turbos are king, and anyone intimately involved with pressurized applications knows it. However, I like the looks and sound of the positive displacement blowers, so that's what I buy. But today's turbo technology has progressed to the point of nearly matching a roots for neck snapping torque and the newest versions can supply HUGE boost without requiring high dollar intercoolers etc, so my next boosted project will probably be a turbo build.

The ability to cruise (under the radar) and attain reasonable fuel mileage and the stealthiness of knowing you can stomp the pedal and go from cruiser to bruiser - without beating up your junks drive train is something that appeals to me.

Thanks for the thread,

Southernman