One looks bigger than the other, but its not. The housing is angled back a bit.


Thats a pic of a Spec C twinscroll setup, but its the same idea with the Legacy twin scroll td04HLA

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RS Liberty - Because WRX's are only good for parts...

Thats a sweet picture. The actual ID of the housing is the same but just stacked on top. Surely that means the circumference is a little bit bigger? much of a muchness really anyho

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MY93 Impreza GX 1.8L, 0hp, 0nm

Matt

I think both scrolls have the same cross sectional area. This is the only thing that makes sense to try and keep even back pressure to each cylinder.

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John Stamos fan club lifetime member

That being said the angle and position the exhaust gas hits the turbine wheel(and the way it expands) would have a great effect on the pressure exerted on it....thus the low/high rpm benifits of a ts turbo.

Even the genuine garret split pulse turbo would in effect have a simular thing going on, since the area of blade on the turbine wheel changes with its position in the housing.... i also would think that backpressure would equalise somewhat due to the 2 scrolls blending together....

I believe the reason that twin scroll turbos work is because they don't equalise the pressure in each scroll before it hits the turbine blade, i.e. the scrolls do not blend before the gas hits the blade.

I would also be very surpsied if the absolute angle of the turbo blade had any measurable effect on the pressure in the headers.

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John Stamos fan club lifetime member

What aftermarket twin scroll dump pipe/tbe systems are available to suit late GD chassis??

any idea where to buy as i've only found the zerosports unit on japanparts and the msr dump (would prefer JDM parts). Ti cat back would be preferred as well. Chime in lads.

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www.racewars.com.au

MSR makes a good dump, I've got one on my car (though, I admit, that's not saying much). Not sure of any other JDM dump pipes other than the Zerosports one, though they should bolt up to any GD tbe?

There a few rally guys who run twin scroll so maybe MMS/RMS/Race Torque etc could offer some advice on where to get good exhausts?

I've got the email address of one of the guys who does the spare parts for the Subaru Australia Motorsport cars who may be able to offer something if you want it? He helped me a lot with twin scroll gaskets.

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John Stamos fan club lifetime member

I thought fujitsubo also did them too

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MY93 Impreza GX 1.8L, 0hp, 0nm

Dont JWS have some 08 (read 2.0 ltr / twin scroll / cable throttle) motors in stock? These engines also have the dual variable valve timing which will net a little extra power but bulk extra torque.

Rather than piss fart around would you not be better off just to do a transplant?

Brendon

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Losing is worse than death. You have to live with losing....

do you know the price brendon?

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MY93 Impreza GX 1.8L, 0hp, 0nm