ok I may know the answer already but Im not positive.

What is the difference between a supercharger and a turbocharger?

Which application is best for a FI 302?

Finally what is each application designed to be used for?

More to ponder about.

 

Turbos are spun from exhaust gasses spinning a turbine wheel, connected to another compressing the intake charge. Superchargers are run off a belt or gears. Supers can give boost right off from idle, while turbos need a little rpm to get them working.

 

Superchargers will give a boost right off of idle if you go with a positive displacement unit, the Kenne Bell is popular one for the Ford trucks. These are much better down in the lower rpms than the centrifical style chargers like the Vortech or Paxton blowers. These ones need to spin up alittle before you feel your boost. Since they need to have a higher rpm before you feel your boost, at the lower rpm it feels like having your air conditioner on, and then some. It's quite a drag on the engine at the low rpm. Kenne Bell is a much better way to go on a truck where you want your Torque down in the lower rpms.

 

I have had one sc mustang and currently own one sc cobra. Other than the whine of the gears the supercharger does not give any clue that it is there. During part throttle you will not feel any additional load on the engine. Regardless of rpm when you crack the throttle the engine accelerates quicker than it would without the supercharger. The roots/twin screw do provide almost instant boost at a much lower rpm and are more suited for truck applications, but do not discount the centrifugal. The centrifugal will give you noticable power and torque in the low rpms as well. BTW, I would not consider a supercharger on my 04 F150 or any truck until I looked into a turbo. The exhaust manifolds and exhaust routing is almost ideal for mounting a small turbo from each manifold. If I was trying to add boost to one of these trucks I would look strongly into a twin turbo setup. 2 small turbos would spool just as quick as a roots supercharger and give you the benefits of a roots/twin screw with the top end charge of a centrifugal.

 

Fraid that aint so ubeenbit...I've had Vortech S trim on a 351 and a Vortech T trim on a torque monster 408 in a 95 Bronco and low rpm part throttle was the pits with a centrifugal. Its like draggin around three air conditioners all running at once! The engine is much, much slower off idle up to about 2500-3000 rpm. With all of the positve dispacement type superchargers you get power all the way through the power band, which is what you want in a truck. As far as top end psi you can get as much as you want with the positive displacement, and without as much heat byproduct. You might have been spinning 6500 in your mustang and a automatic truck shifts out of the box at about 44-4500,and trucks weigh close to three times what a Mustang wieghs. All of these add up to the centrifiguls not performing nearly as well on the trucks.

Again, the same holds true for turbochargers, they dont come on until 3000-3500 rpm's, thats 3/4's of your rpm range for alot of trucks!

Check out some of the tech info on th Kenne Bell site, it will help shed some light on all of these different types of SuperChargers and Turbochargers. Kenne Bell, like any of the positive displacement Cos. have done alot of Dyno testing on all of these different types and the Dyno dont lie! Check it out!

 

Let me ask you a few things.

When you open the throttle is the centrifugal helping air get into the engine?

When you mashed the throttle with the centrifugal you are saying that you accelerated slower with the centrifugal than you did n/a? below 2500-3000rpm

2 small twins could be set up to show full boost by 2500rpm, would make as much power as the roots/screw with less boost.

The only time I can think of that a sc might and I say might be noticable is at just off idle rock crawling. I know on both of my mustangs performance from idle to redline in all throttle positions and engine loads was improved dramatically. I say physics do not lie. As long as the engine is running the sc is assisting the engine digest air, tip in response, acceleration, part throttle, all should improve as long as the engine is tuned correctly.

I do agree that a centrifugal is not ideal for a truck, but I also believe that it will not hinder performance either, with a proper tune.

I also believe that 2 properly sized turbos would give you the best performance out of all of them.

Just out of curiosity who tuned your setups and were both of them FI or carburated?

 

Hey ubeenbit,

Both of my systems were MAS and were tuned at Charlies Mustang's when he was still alive.

If you have any doubts about what I experienced at the lower RPM's, please do check out Kenne Bell's site, I am far from alone on my experiences with a Centrifugal SC on these trucks. They have Dyno charts to show the difference in the two styles too.