What is the best, Turbo or Blower??

[nthfinity]

there are all sorts of impeller /compressor configurations for turbos that all perform unique to itself..... some have small compressors, and larger impellers to give boost right off the line, but they die out in the upper rev band.... and they go to the other extreme
superchargers come in 2 basic configurations, roots type, and screw type. the roots type is typically cheaper to make/install, but ends up "robbing" the engine of 50-80 hp, whereas a screw type seems to keep working right on up the rev band.
hope that helps
gtp has a roots type, mustang svt has a roots type, ford gt has screw type, mercs have screw type.

[zevolv]

Roots and Screw are the same thing the different styles are roots/screw and centrifugal. A roots is also called a twin screw supercharger that's where the name screw comes into play.

[graywolf624]

Roots and Screw are the same thing the different styles are roots/screw and centrifugal

Wrong.

Officially there are 3 types. Please at least bother to read the article I posted. The only difference between a root and a screw are that a screw internally compresses air while the screw does it externally. As such the screw is more thermal efficient.

The Twin Screw Supercharger The twin screw supercharger at first glance appears to look similar to a roots supercharger both inside and out.The two technologies are indeed similar, however there are significant differences.At the heart of the twin-screw supercharger are two rotors, or “screws” that rotate towards each other. The rotors mesh together and draw air from the back of the supercharger.The twisting rotors move the air to the front of the supercharger, while compressing the air before discharging through a port at or near the front of the supercharger. Because the compression is done inside the supercharger, this design produces less heat than a roots supercharger— in fact, it is almost as thermally efficient as a centrifugal design

Here is another article. As you can see the main difference is the direction of rotation of the lobes.

http://www.kennebell.net/techinfo/ge...romcatalog.pdf

[TeflonTron]

Can someone explain to me how SCs "rob" power from the engine? I'm assuming that it's a case of they add, say, 150BHP, but because of mechanical "leeching" tey then lose 60BP of this? Someone please explain, as this has always confused me a little.

[coombsie66]

From what i understand it is as u assume, the supercharger is run off of the crank, which is usefull power, which would otherwise be used at the wheels. So it may add a certain amount of bhp, but in doing that it will rob the engine of a certain amount of power to spin the charger.
Im not sure why, but i think that chargers limit the power of the engine more as the rpm's rise.
If sumone could ellabourate feel free!

[SFDMALEX]

Originally Posted by blah Originally Posted by SFDMALEX It does depened on the engine I guess. If your car only revs up to 5000rpm then I dont think you'll get much boost from a turbo. so a blower is this case. If your car can rev up to 8000rpm then the turbo will have enough room to spool up completly and stay like that since you'll not get below 3500rpm....on a track..... Anyway Im not expert, just my own little "theory" not neccesarily, because ones its spooled up, the turbo is will be there, the problem with the turbo is the spooling time, some people defeat this by using a smaller turbo, and a larger one, the small one goes first, while the large one spools. There are hundreds of vids, and pictures of turbo stangs, maros, corvettes (lingenfilter), vipers, and other cars.

speaking of the spooling time.....the more cylinders an engine got the more exhaust it produces the more presure it can create on the turbo. So you can put a big turbo and have decent spooling times.

Ok new theory here lol. If you got a 12cylinder beast under the hood you gotta go with a turbo.

[coombsie66]

^^ It depends onthe capacity of the engine as well.
I think you dont put more 'pressure' on the turbine blades wiv more cylinders, its just that there are more smaller exhaust gas pulses than less larger ones in the same capacity less cylinder number engine.
This is where the exhaust manifold design is paramount, as you are trying to make the path lengths so that the exhaust pulses arrive at an even rate to the turbo.