justinschmidt1 said:
it is true that a centri blower is more efficient at higher rpms right?
So when your at the track running the car from like 4500-6k all the way down the track it only makes sense that a car with a vortech at 9 psi would be faster than a KB car with 9 psi since the vortech car will be making more power all the way down the track.
This is assuming both cars are launching at like 5k and can actually hook.
In theory with the characteristics of the blowers that should be true. But the main problem in these cars is that the factory intakes on are a bottleneck to a centrifugal supercharger (or turbo) reaching it's full potential. If you had a good intake like the Fox Lake P-51, an extrude honed bullitt intake, etc., then it'd be a different story but a stock PI isn't able to fully take advantage of a centrifugal's benefits. Look at even the turbo cars, ones that are in the 400rwhp region, they 480ish rwtq around 4000 rpm in a lot of applications, torque curve falls off pretty quick and consequently peak power isn't what it could be. It's pretty indicative of how much a restriction the stock intake is because a turbo car should murder a KB car in high rpms due to the efficiency difference. Heads and stock cams are part of that bottleneck as well.
The Kenne Bells replace said manifold so really they remove one bigger restriction and both applications at 9psi the Kenne Bell even makes more top end power in the 5000-6000 region on top of the added low end torque. Apples to apples most KB cars make in the 400rwhp region after a good 9psi tune like from T&J or similar, centri cars in the 400 region are pulleying down, intercooling, adding boost pipes, and turning around 10-11psi to get in the 400 region.
Of course, keep in mind boost is just indicative of the airflow your heads/intake/cams/exhaust are capable of. Put the same blower, pulley, etc on two engines, say a NPI vs a PI, the more restrictive (NPI) one will show more boost just because the set amount of airflow is, for example, 9psi higher than the engine would flow if it were naturally aspirated. Port the heads, etc. boost level will drop even though the level of airflow is the same. So a KB at 9psi can be outflowing a Vortech at 11 for example, just because the intake is that much of a restriction compared to the KB intake. Until you upgrade the intake, cams, heads, you really can't take advantage of a centri setup like you otherwise could. Once you do all that, you're going to need to build the bottom end, upgrade the fuel system, and all other odds and ends anyway and once all that is done the centri does outdo them up top. If you want to make big power in the long run, something like a T-trim or Novi 2000 is a good investment though because once you get the engine and fuel setup in place you can make more power in the long run.
