superchargers

I just want to know why no one supercharges their imports its always people turboing.

preference i guess.

Towards lude_si's original post>>>>Thats not always true. A lot of people have turned to Vortech superchargers lately(even tho I believe they are a little pricey), and I know a few people around my area that have JR superchargers on their cars.

Overall it really is preference.

Some people want the quick,responsive boost that a roots(JR) supercharger gives because their car has little or no low end torque, but they sacrifice some of their top end power. Full boost begins as soon as you hit the pedal(so low end torque is crazy big), but after say 7500 or so rpms, boost has a slight tendency to max out and actually drop off a few psi. Another problem roots superchargers have is that you have to upgrade your pulley to up the boost.

Some people want top end power, but really don't want to sacrifice much of their low end torque so they go with a centrifugal supercharger(Vortech). The boost starts out as soon as your hit the pedal(to add some low end torque), but it doesn't reach full boost till the later rpms(boost rises over the rpm range), so you still have good top end power. Problem is, you also have to upgrade your pulley to up the boost.

Now on to my personal favorite, turbo. Some people want incredible mid-range and top-end power that a turbo can give. Of course your will have some lag in the lower rpms because of turbo spool, but if you buy the right size turbo for your application, lag really shouldn't be a problem. Boost on a T3 turbo starts round 2500-3200rpms(guesstimate) so there really is no problem with lag, but a T3 turbo won't be able to produce as much horsepower as a larger turbo(around 300-350ish). A T3/T4 hybrid is a good idea for most honda/acura/etc. becuase the boost will usually start around 3200-4200rpms so there might be a slight problem with lag if you punch it in 3rd or a higher gear, but you can still get amazing hp(500+) Then you have the big boys(well to honda/acura engines these are the big boys) the T4 series. A TO4E or TO4B turbo will create amazing amounts of hp(650-750+) but lag could be a slight problem, your turbo might not start spooling until 4000-5000rpm range(or possibly even later if it's bigger than really needed for your application) and for some people this could seem like forever.

Now I know I really didn't touch on all of the specs on either superchargers or turbos(especially not superchargers, so if someone wants to help me out, your help would be more than welcome; same goes for whatever I missed on the turbos too) Now this wasn't meant to be a detailed explination for either one, I'm just trying to lay out a very very basic example of the differences between superchargers and turbos used on most honda/acura engines and the reasons why people would chose them.

P.S. For the people that know a lot more than I do about FI, go ahead and flame away at my mistakes and please make sure to correct them along the way. But please don't be to harsh :uhoh:

MastaCivic, you seem to have covered it pretty well, but I'll toss in my two cents since I'm bored.

Roots Type Super-Charger:

The roots type super-charger is belt driven. This gives you instant power from the second you push the throttle. There are many problems with this setup. For one, since it is belt driven you will experience parasitic loss. Just like any belt driven accessory like a water pump or air conditioner the roots type blower will use power from the engine. The second problem is that the roots type blower is always boosting. It doesn't matter if the engine is at idle, cruising, or under load the blower is in boost. This means it is pushing more air, which means more fuel so you will take a hit on fuel mileage. The third problem is that the roots type blower is only efficient in the low end of the powerband. In my opinion it is horrible to make all your power at the low end of the powerband since in most racing the engine is kept in the mid to high end of the powerband. And the last problem is that a roots type blower does not compress air it simply moves it faster. The problem with this is that you are moving uncompressed air into a compressed environment. The blower delivers more and more air rapidly into the intake manifold, where it compresses from the addition of increasingly more air. The turbulence of uncompressed air entering the compressed environment creates heat and heat equals loss of power.

Twin Screw Super-Charger:

A twin screw super-charger works pretty much the same as the roots type except it compresses the air before forcing it into the intake manifold reducing heat. It is also more efficient to about 80% of the powerband. However; it still shares the problems of reduced fuel mileage, parasitic loss, and still is not quite as efficient as a turbo-charger.

Centrifugal Type Super-Charger:

A centrifugal super-charger works much like a turbo-charger except internal gearing determines when the compressor boosts. Also, instead of being powered by the exhaust it is belt driven so it will cause parasitic loss just like the other super-chargers. However; this is the only downside that the centrifugal shares with the other super-chargers. You can design a centrifugal to deliver boost whenever you want it to, but most are designed to deliver boost at a higher RPM and won't deliver boost until above 2,000 to 3,000 RPM.

Turbo-Charger:

This is my favorite type of forced induction. The turbo-charger is driven off the exhaust off the car so it uses free energy making it far more efficient that any super-charger. However, this causes turbo lag which is the time it takes for the exhaust gasses to spool the turbine. This is becoming less apparent because of lighter materials and new technologies. You can get turbo-chargers that spool low as 2,000 RPM and can hold full boost to redline. It is a simple matter of matching the correct turbo with your engine. Turbo-chargers also only boost under load. So the only time it is boosting is under acceleration or going up a hill. If you are at idle or simply cruising down the road it is not boosting saving you fuel. You can even manage to accelerate without boosting. Once the turbo spools, if matched with your engine, it can hold boost through the entire powerband. Turbo-chargers are also easier to work with. All you need is a good boost controller to change boost levels to whatever you want. With a super-charger you have to change out the pulley, to me that is just a pain in the ass.

It is my opinion that a turbo-charger is the best form of forced induction around. There are fewer downsides and more upsides to a turbo-charger than a super-charger. The nice thing about both is that they reduce strain on the engine. For an N/A engine to make the same amount of power the engine would be higher strung. Also, there are people super-charging four cylinder engines, just not very many and I can see why.

:2cents:

ok nice input but never seen any superchargers in my area on imports I was just wondering bc i didnt see y any one wouldnt but i would personally prefer a turbo

ok nice input but never seen any superchargers in my area on imports

Yeah its not very often that I see one either, I've seen 2 or 3 SVT Focus' supercharged and a really nice 95 Hatch with a b16a that has a JR Supercharger on it. The SVTs are fast but that hatch will absolutely fly. This could be because the guy is a rich bastard using mommy and daddy's money to build his whole engine. Pistons,rods,P&P,cams,header,completely upgraded fuel system, etc. etc. etc. and all of this stuff is top of the line. I don't know his 1/4 mile times because there isn't really access to a 1/4 mile track around here, but I would say he'd run in the low 13's and possibly high 12's(just an estimate).