'ello all,

Besides lack of space in the engine bay, is there any technical reason you can't put a supercharger onto a WRX/STi?

 

Price vs a bigger turbo so why anyway, although has it been done?

 

I don't know, hence the question. As I see it you would then have the best of both worlds - low down (and through the rev range but the main benefit for a Scooby would be low down) power via the supercharger and then the kick of the turbo higher up.

 

Has been done, someone I know as a supercharged STi engine in the back of a Metro coupled to a hewland transaxle - absolute flyer. This is an autograss car which races on 1/4 mile dirt ovals so low down torque is critical for acceleration, hence the instant response of a supercharger is usually prefered over a turbo.

Trouble is I think they are having trouble keeping it in gearboxes!

Its an awesome piece of kit. Not spoke to him about it so don't know spec's etc or who did it but Baines Race Engines springs to mind, I think they supercharged him a 2.0 pinto engine previously.

 

there is room if you dont have air con.. or you could move the battery and sit it to the side..

recently found out its called compound charging when you have turbo and supercharger..

David

 

Are there any companies that actually do this on a regular basis? i.e. have the expertise born out of experience?

 

Power Engineering used to Supercharge the fords using a Sprintex.
They couldn't get the fuelling correct though as there wasn't the scope with the old Bosch Jetronic injection system.

If they claim to be Subaru experts now I'm sure they would be able to offer their experiences.

Anybody remember the rally Lancia 037( think that was the model)
that was compound charged.

 

Was wondering about this but for the bottom end only.

Use a solenoid operated clutch to disconnect the drive to the supercharger once over a set boost level which would be set to be as the turbo was mid spool. This would remove the considerable losses you get (more than EGBP from driving a turbine). You could have a very nice flat boost from 1000-4500 RPM? And then use a large turbine and compressor without worries about surge low down or excessive EGBP at 8000 RPM.

The other solutions are for an all rounder with big power as I see it:

Raised capacity, but troublesome over 2.5 for packaging and weight

Twin turbo - raid B4 RSK manifolds/exhaust? VOD and overspool issues should be able to be overcome with some thought.

VATN or solenoid controlled twin scroll, but really limited to low power passenger cars so far because of loading?

Have to say the B4 idea appeals most. Starting new thread to avoid polluting this one.

 

remember seeing a integra with a HKS supercharged and turboed engine think it made about 400-500bhp.