What do superchargers do different from turbo's ? And has anyone done it to a N/A zed before?

 

Just wondering, as im quite interested

basically, a turbo sucks the air out, the supercharger blows air in. they both create the same effect but with a supercharger you don't get the turbo lag that you get from a single turbo. not a problem any more with twin turbos.

Originally posted by mikecotton

basically, a turbo sucks the air out, the supercharger blows air in. they both create the same effect but with a supercharger you don't get the turbo lag that you get from a single turbo. not a problem any more with twin turbos.

 

 

:confused: 'Sucks air out!!!!'

 

Both are forced induction, a turbo is exhaust gas driven, a supercharger is belt driven, that's what I thought.

Explained here;)

 

http://www.fordvschevy.com/tech/tbsc/tbsc.html

Originally posted by mikecotton

basically, a turbo sucks the air out, the supercharger blows air in. they both create the same effect but with a supercharger you don't get the turbo lag that you get from a single turbo. not a problem any more with twin turbos.

 

 

Muhahhahahahahah!!!

 

Charger compressor is driven by the crank hence no lag.

Turbo sucks air out. ;) well nearly the exhaust gas spins a turbine which has a compressor on the other end of the shaft which sucks air in and compresses it.

:D

:rofl: :dance:

Oooohhh yuk! What the hell is that thing?

Originally posted by Scottywil

Oooohhh yuk! What the hell is that thing?

 

I guess you mean the mitsi?

It was his baby until he wrote it off last night. :(

Damn! Feel guilty now!

Originally posted by Jezz_S13

I guess you mean the mitsi?

It was his baby until he wrote it off last night. :(

 

Sorry to hear this,hope he is ok ,what happend,is it a complete right off,he had if i remember done a fair bit to it:(

superchargers also tend to run out of puff later in the rev range, when turbo's are still giving it large!

 

supercharging & turbocharging is the way to go (& the little nissan micra was the only production car to do this i believe ;) )

 

GB on Superchargers??? :D :cool:

Originally posted by Paul C

superchargers also tend to run out of puff later in the rev range, when turbo's are still giving it large!

 

supercharging & turbocharging is the way to go (& the little nissan micra was the only production car to do this i believe ;) )

 

GB on Superchargers??? :D :cool:

Depends on the type. A Roots type supercharger will run out of puff generally later in th rev range, and has a lower adiabatic efficiency, up to about 60% (it heats the air up more for the same boost).

A centrifugal supercharger will create more boost the more the engine revs, peaking boost at the redline (adiabatic efficiency can get close to 80%)

A whipple type supercharger will create constant boost from very low revs and hold the same all the way to the redline, with better adiabatic efficiency in general than the other two. (up to 80% again but gererally better than centrifugal)

Both are forced induction units.

 

Superchargers come in many forms. Most are positive displacement. For each revolution of the crank it will displace a certain amount of air into the inlet. Therefore the charger must be attached to the crank by some means. In doing this every turn of the engine will produce pressure and therefore unlike a turbo you can achieve significant power at low revs. Although in practice at low revs there is some leakage. Chargers are also more suitable (but in no way limited to) carburettor based setups.

 

Downsides are that at high RPM a blower can add a lot of heat to the charge and therefore become inefficient. Also because they run directly from the engine they need power to produce power and therefore take away final engine output.

 

Upsides are good power low down the rev range and due to the lower pressure chargers normally generate and the slower speeds they run at they can be more reliable. For a lot the lack of lack is a big upside.

 

Turbochargers comprise of a compressor and a turbine. Both of these are connected via a shaft. The turbine sits in a housing which directs the exhaust gases from the exhaust manifold across the blades of the turbine and out to the exhaust system. This spins the turbine and because the shaft connects it to the compressor, the compressor spins and produces pressure. The compressor also sits in a housing. One end connected to the air intake, the other goes towards the engine intake. Commonly a charge cooling device is after the compressor side and before the throttle/engine intake. More exhaust gas = more compression. To stop a turbo running to distruction a wastegate (either internal or external) bleeds exhaust gas away from the turbine to allow it to operate at a constant pressure.

 

Downsides to a turbo are lag. You obviously need a certain amount of exhaust gas to generate the turbine speed which in turn generates the pressure via the compressor. There are however anti-lag techniques which can negate this effect and usually reduce turbo life.

 

Upsides of a turbo are big boosts attainable at high RPM. Also a turbo doesn't take any power from the engine to operate.

 

Twin turbos can indeed reduce lag but setups can be very complicated. Twin turbo systems normally are better on V or Boxer type engines with a turbo for each bank of cylinders. Again ensuring these work correctly with each other can be a complicated design. Many tuners will remove the twin turbo setup and go for a well designed single turbo.

having owned both turbo and supercharged cars the only real difference is the bit of lag till the turbo kicks in, i think that you get more kick from a turbo than from a supercharger, or maybe thats just comparing a vw supercharged engine to an obviously far superior nissan and mitsubishi engine!!!!

 

but then, because you cant feel the supercharger kicking in as much as a turbo thats maybe why i think like that.

 

scottywil and tony, im ok, no one was injured, got a bit of a slap from the airbag.

id spent a bit on the car (just over £1k) putting it right, but i'd had this taken into account when i bought it.

rather than higjack this thread i'll put a link onto my post on sxoc so you can read for yourself what happened!

 

http://www.sxoc.com/vbb/showthread.php?s=&threadid=67516

 

:cry: :cry: :cry:

Thanks for your help guys - ive learnt something now !!;)

And me, and I even got around to looking up what a "boxer" engine actually is, cos the article mentioned them. Cor.