Pitzi

Hello people

Couldn't find much info on the net, so I am trying here.

How good is a VF37 twin scroll turbo?

What kind of flow can it achieve??
What kind of boost can it hold??
Has it got good bottom or top end??
How does it compare to lets say a Garrte based 400hp??
Would it be able to flow enough for a 400hp 2.0L??
Does it need a different downpipe?? are there any decent downpipes for these twin scrolls?
Does the use of a twin scroll turbo kill the boxer beat altogether>??

Any info appreciated (oh and I know about the manifold issues! )

Fuzz

what manifold issues ??

I'd expect to be able to screw 350 horses from it with supporting mods.
(Bob R got more than this but that was on an STi-9 with AVCS/VVT.)

It will need a different manifold to the normal exhaust housing yes.
Miltek do a nice one, I've fitted a couple

Andy

Pitzi

Hello Andy, thanks for the reply. I just wanted to point out that I know that you need a different manifold setup to use a twin scroll. Basically I want to find out what kind of modding potential does a twin scroll equipped Impreza have, such as Jap Spec STi and Spec C.

What kind of "supporting mods" would you suggest?

I have been thinking of doing the following: (car is an MY05 S203)
FMIC
ECUTek
Modded fuel rail
500hp fuel pump
bigger injectors
Air intake kit with cone filter
3" exhaust (hence my downpipe questions?)

Thing is, I am not sure wether the twin scroll would be able to flow enough air to achieve 400hp, which is my ultimate goal.

I would like to know if it might be better to use a normal IHI VF35 equipped STi and go the garret based 400hp turbo to achieve the power figures.

sparkywrx94

you could maybe reach 400 bhp if you modify the VF37 compressor side with a bigger compressor wheel.

I am doing a twin scroll conversion on my classic impreza, have just bought a very nice 3" downpipe from www.performancesubaru.co.uk. They are very helpfull and efficiant. They have done a few conversions to twin scroll themselves.

Pitzi

Thanks for the helpful info mate. I take it then that in std form the VF37 doesnt flow enough for that power figures??

What about boost levels, anyone knows what it can hold and up to what rpm??

sparkywrx94

I have been told that it will hold 1.4 to the redline with a peak of 1.5 midrange, dont know if it can do that. have a look at Bob R's thread in projects.

http://bbs.scoobynet.co.uk/showthread.php?t=283364

Fuzz

I was informed today that my above quote was not with just plain pump fuel !!....
I know the Spec C runs around 320BHP using a similar turbo.

I'd have to let you know what the outcome of the current project car I'm doing at home for someone (Snowcrash) Sti-5 heads and inlet manifold with a VF37 twin up pipes/headers/sump etc with onto an STi8 block ( standard hypeurtetic (spelling) pistons) everythings ground to a halt though, in the search for some inlet and exhaust valves for it. (not costing a gazzilion quid that is )

Andy

Pitzi

Thanks guys.

Bob Rawle

Spec C uses a VF36, its not good enough in std form and won't hold 1.4 bar to redline either, least not on a spec C or GL.

as per other thread gerado yhm

bob

sparkywrx94

Bob,

What sort of boost can the VF37/36 peak to in midrange before hitting surge line.

have you come accross any compressor maps for these turbo's.

Regards

Mark

also can you tell me what type of uprated actuator you put on the turbo to make it hold the boost.