carl 00

Has anyone fitted a super charger to their impreza Plus the turbo??. I've just read about a vw golf with it on and they say it overcomes turbo lag......

joz8968

iTrader: (13)

Superchargers are driven directly by the crankshaft, hence the instant low down grunt. But because of the really low 6k-9k rpm limit of a petrol engine (compared to the 80-100k rpm limit of a turbocharger!), they can't achieve and maintain really high levels of airflow through the engine... But... that's where the turbo would take over.

My fave dual super/turbo car is the famous mid-rear engined, 4WD Lancia Delta S4. Mmmmmn.

The typical 'screw'-type super charger is a big ol' beast and it would be a logistical nightmare trying to integrate one on the EJ turbo engine, etc. Also, they're not that efficient - they sap about 30% of their potential power output in heat through internal losses, etc.

TonyBurns

iTrader: (3)

Yes and that vw golf isnt exactly known (the GT) for being a wonder to drive because of the supercharger/turbo combo.

Tony

carl 00

Is that the dutch blue one that is in redline mag may 09? I mean tecnicaly if you threw the air con away you could put one there mabe?

TonyBurns

iTrader: (3)

Technically you could, but with twin scroll turbo technology, its a bit of a waste of time

Tony

RedScoob

There was a tuned new age Impreza that was making the rounds on here a couple of years ago that had two turbos and a supercharger (IIRC). Hopefully someone will post a link. Looked pretty awesome though, instant grunt from low revs in an Impreza seems like a lot of fun!

carl 00

Yeah sound's fun to me, explain twin scroll to me!

Splitpin

Why not use the search button and find an explanation someone else has already written? Just an idea like.

carl 00

yeah could forgot about that!!! I wanna see this one that has been done anyone got a link?

mit

iTrader: (10)

This one? https://www.scoobynet.com/members-ga...arged-sti.html

RedScoob

That's the chappy!

carl 00

That is just amazing, Don't think it would fit under the bonnet of my classic bugger! I might have a go tho lol

apalmer

iTrader: (8)

But your only considering positive displacement superchargers when you say that, yes parisitic losses are greater with superchargers due to their mechanical attachment to the crank, but a positive disp supercharger setup will see higher load or boost before a similarly sized turbo setup. If a smoother curve of power is desired from a supercharger, say for a track setup or fast road, then a centrifugal system would be an alternative as these make peak boost at redline, with peak power being somewhere before this point. Also losses are reduced with this type of supercharger setup. A positive disp supercharger would be an ideal configuration for a drag application due to the speed at which power increases, power will tail off on a system like this, but as a drag app this isn't so much of an issue.

Just because a turbo could potentially flow more cfm of air doesn't necessarily mean this it is translated into real engine power. The only real comparison would be to compare the compressor map of the turbo against that of the pulley ratios of the supercharged application and apply it to the engine, taking into cosideration inlet runs and cams etc. Something you would need extensive testing on the dyno to calculate.

Fitting could be pain