Supercharger question

rabidh

I just noticed a thread on pistonheads about the AutoDelta Alfa V6:
http://www.pistonheads.com/news/default ... ryId=17153

It has a picture under the bonnet of their arrangement using a centrifugal supercharger... I started reading a bit about them on wikipedia, and it all looks quite good really, with the article saying the lack of boost at low RPM means that you can run them easily on an otherwise unmodified engine.

They look so easy to fit as well, as you just need to place them somewhere you have drive (where the aircon pump should be?), and then pipe them in (possibly using a turbo intercooler) - none of this messing about with special manifolds like on the roots-type ones.

I can't honestly say I'd supercharge my VX (at least until I win the lottery!), but I'm curious why all the conversions i've seen use the roots-type superchargers. Are the compressor-type ones unreliable or something? Or is it just that cars with Ecotec engines are after torque rather than high-revving power?

vocky

the roots type give more pressure for a smaller size - the gears compress the air

the centrifugal blowers are generally a bigger size - they compress the air by the speed of the fan blades

my experience with industrial versions is the centrifugal blowers last longer, but the bearings do fail on both types

slindborg

the standard z22se wont like revs past about 7.5K as its got a masssssssive stroke and fairly long rods from what I can make out. So yeah you'd ideally want power low down to limit, OR destroke the engine to 2.0 and make the little cow rev to 10K like they do in the build book lol

exmantaa

Hitec is working now in their "phase 1" with a centrifugal blower in the speedster.
http://www.hitec-automotive.de/kompressor.php

I think they still use the GM blower for their bigger power Z22 conversions...

A centrifugal blower is (very) small compared to a roots type. And has a good efficiency, but only works good in the higher rpm's. I think the Delta uses a twin screw compressor. This type also has a very good efficiency, work with higher boosts and has low-down torque...