Centrifugal Superchargers

[NewyorkKopter]

Hey, I have a couple of questions about centrifugal superchargers
1- Do they make the whistling noise simliar to Turbos?
2- Do they require something like a blow-off valve or turbo timer?
3- Do they provide good horsepower gains?
4- Are they good for long term use, like does the belt stretch or break in any situation?

[Reed]

1) they do not wistle like a turbo but they will whirrr (i guess is the sound). a centrifugal supercharger will only spin between 2 to 3 times faster than the engine RPM (im guessing based on pully diameters). Turbos spin up to and sometimes above 150,000 RPM

2)if it is intercooled you should have a blow off valve

3)yes

4)i guess the belt has as much chance of stretching or breaking as a timing belt, but you will be much more screwed if your timing belt breaks

[NewyorkKopter]

how often does the belt stretch or break? would a twin centrifugal supercharger setup be reliable??

[beef_bourito]

yes it would be reliable but there isn't much of a point of having a twin centrifugal supercharger system, the plumbing isn't nearly as complex as with a turbo system, it's just like the plumbing for a positive displacement supercharger.

You do need a blowoff valve (or at leased you should) but you do not need a timer. the point of a turbo timer is to let the turbo cool down slowly so that nothing warps, stresses, or cracks. a supercharger doesn't produce anywhere near the temperatures ofa turbo because it's not involved with the exhaust.

[NewyorkKopter]

true, check out this Diablo SV's twin supercharger setup. Would the belt snap/warp in a car with a huge 600+ hp engine like this?

[Reed]

i would not worry about the belts snapping or stretching. even if they do nothing bad will happen just replace them. that system would be very reliable but i think it is only a twin setup for looks and because that is what fit best. i think a single charger system would be more efficient and provide better power.

[beef_bourito]

the only reason to have a twin supercharger system is looks and space, if you can fit one bigger supercharger you might as well do it, it'll be cheaper and more efficient.

[beyondloadedSE]

Originally Posted by NewyorkKopter

3- Do they provide good horsepower gains?

imho they work best on large displacement engines with already lots of low end torque. Since its rpm dependent, power is very linear and as a result, torque increases arent that great and doesnt make nearly the power under the curve as a roots style blower. With the Vorcrap *cough*, Vortech unit for the Ford Contour, boost isnt seen until nearly 5,000 rpms and doesnt reach max boost redline. It provides only about a 45 ft-lb increase in torque. Its nothing but a dyno queen unit. Not to mention, 12 psi is about the max it makes since the pulley can only be made so small.

and btw, superchargers should have a bypass valve regardless of whether its intercooled or not.

[longlivetheZ]

That's what I was wondering...why would it matter if it's intercooled or not? It should have a bypass anyway.

Having a twin supercharger setup would be about as practical and necessary has having a supercharger + turbo system. Is it possible? Sure...but why bother?

Most centrifugals I've heard were REALLY loud. Heard a 350Z once that sounded like someone dragging a fork across a chalk board. Thing went like a MOTHER fucker, but it sounded REALLY really really bad, imo. As far as I'm concerned, nothing does, can or ever will sound as cool as a turbo spooling up with a nice blow off valve.

[NewyorkKopter]

lol, I thought they'd sound good.

[longlivetheZ]

You can't hear most of them too much. That specific one I heard was REALLY bad, though. I don't know what kind it was. That was a really fast car, too...too bad it sounded stupid...lol. Guess it doesn't really matter.

I don't know what the big deal is with superchargers these days. Seems like everything is running them and only a hand full of cars are running turbos even though turbos are so much better power adders. I just don't get it.

For a bit of perspective...top fuel dragsters...~500 cid with ~5000 hp = ~10 hp/cid. Not bad. But think about the 90 cid turbocharged formula 1 engines of the mid/late 80s. They were pushing 1300-1400 hp! OUT OF 90 CUBIC INCHES!!! That's an impressive ~15 hp/cid.

I guess everything has its use, though. I dunno.

The FASTEST car I have EVER driven, HANDS DOWN, was a Neon SRT-4 with the Mopar Stage-2 kit. Factory installed...warranty...whole 9 yards...that was the fastest fucking car, man. My girl was brave enough to ride with me on the test drive and she kept telling me to stop flooring it cuz she was gunna puke...lol. I was laughing my ass off. Go to mopar.com to check out all that's involved...cool little package they put together.

[NewyorkKopter]

true, but as far as I see it...
Superchargers- for people who want power and who want to keep the car streetable
Turbos- for people who want insane amounts of power, and lap times

[beef_bourito]

you can keep a trubochaged car streetable, very easily too. in fact i'd say a turbocharger is better than a supercharger on the street. you get better gas mileage and if you get a properly sized turbocharger you don't have much, if any, noticeable lag.

[Black Lotus]

Originally Posted by NewyorkKopter

true, but as far as I see it...
Superchargers- for people who want power and who want to keep the car streetable
Turbos- for people who want insane amounts of power, and lap times

High HP OEM turbo cars appear to be very streetable.
The same HP aftermarket equipment turbo cars can be steaming piles of crap on the street. It depends on who's doing the engineering and installation.

[NewyorkKopter]

yea, thats why I like Turbos alot better, they can be used in either