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Discussion Starter #1
Does anyone know anything about scroll compressors? I know Volvo uses them on their I-5 engines (twin turbo, intercooled) and that they are very similar to some A/C scroll compressors. Supposedly, they have no lag at all, and act more like a supercharger, although they're still run by exhaust gases. This seems to make sense since many of the new Volvos have torquey powerbands, although they're TURBO, not supercharged. Can this type of turbo be applied to an import (as in Japanese) engine too?

Imagine the possibilities... :cheeky:
 

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hmm

sounds interesting , got a link or something i could read up on it with ?
 

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Discussion Starter #4
www.volvocars.com Check under a car's specs. I think the S40s have it, and my mistake; it's found in the I-4 engines, not the I-5s like I posted earlier.
 

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Hmmm. Judging my the compression ratio (10.3), I would have thought it's going to be a fairly light pressure turbo. I'm also getting the impression that it's a Twin-Scroll turbo charger, rather than twin scroll turbochargers.

Scroll turbochargers are suppossed to be very effecient, so maybe they provide a little boost all the way acrosss the rev range.
 

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twin-scroll turbo

From the S40 engine specs:
"This engine utilizes a "Twin-Scroll" light-pressure turbocharger that reduces throttle response time (turbo lag) by about half that of a conventional turbo. The twin-scroll design pairs up the exhaust pulses from cylinders 1 and 4 and cylinders 2 and 3 into two ducts feeding the turbine so that the turbine spins up to speed much quicker.

Boost pressure for the system is reduced to 8.7 psi (0.6 bar). This results in smoother, more even acceleration, and better "driveability," but less maximum performance than a high pressure turbo.

The engine maximum power output is
160 hp, reached at 5,100 rpm. However, most of the effects of the engine design and the light pressure turbo technology are on torque rather than maximum power, which is much more useful in everyday driving.

The maximum torque of 170 ft. lbs. (230 Nm) is available over a very wide engine speed range, 1,800 rpm to 4,800 rpm. The engine thus provides high torque for good response and acceleration throughout the speed range where almost all normal driving takes place. This also has a positive effect on fuel economy, compared to higher performance turbo engines.

The engine features Continuously Variable Valve Timing (CVVT) on the exhaust camshaft to help keep emissions down during cold starts. This engine fulfills the Federal LEV standard emission requirements."
 

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Discussion Starter #8
So it can't push the pounds like a conventional turbo, but it reduces lag...

Good thing the FC3S had twin-scroll turbos for emphasis on torque, cuz rotary engines are kinda jippy on that.

So can this be used on an SR20DE?
 
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