Turbo: T40E .81 AR
S/C : Eaton M62 2nd Gen
Coupling: Direct belt
Engine: irrelevant
This is a Twincharged motor. It has a direct drive M62 Eaton blower on the intake and a T40E on the exhaust. At start-up and low rpm conditions the supercharger is boosting the motor, but as soon as the turbo spools up it's driving the whole system. Since the S/C is connected to the crank by a belt it becomes a driven component any time the turbo is spooled. That means that it is being spun by the pressure in the system and returning some of that energy back to the engine through the crank by way of the belt. This is a standard practice in aircraft motors and there is no reason why this same principal can't be implemented in an automotive engine.
Specifically in the case of the RedLine there are a few advantages it has over that of the engine above; a Throttle body (charge pressure governing control), an internal M62 bypass valve, and an advanced fuel and timing control system.
With the internal bypass valve of the M62 blower there would be no reason to clutch the supercharger. Any extra pressure that would normally drive the S/C could be diverted through the bypass valve. This keeps an equal pressure on both sides of the S/C resulting in minimal HP loss from it spinning and no temperature increase since there is no pressure delta between the open air and manifold side of the S/C. Even if the bypass was closed it would actually return a part of the wasted HP back to the motor through the crank by driving the S/C like in the engine above.
The throttle body actually provides a way for the charge pressure and or air source to the S/C to be limited. By changing the volume of air entering the engine it will control the overall performance and efficiency. Obvious, but stated to make aware of its function.
Additionally the fuel and timing control of the engine is capable of offering a VERY lean operating state for low load cruise conditions and a very power friendly operating state for high load WOT runs.
---===---
Saturn and GM are also working on assisted power starter/generators to be implemented on vehicles starting in 2007 (I think that's the year) . They are basically starter/generators that can either operate as a motor to provide either assisted support for more power acceleration or total power for "electric" driven cruise modes and as a generator to recharge the battery system that operates the whole vehicle.
With the RedLine the simplest way and least expensive way to increase both power and efficiency would be to install a Turbo on top of the supercharger. A $2500 turbo system that includes everything in the world could be tuned for maximum power beyond 350-400 HP and efficiency in the range of 0.45-0.50 BSFC (how much fuel use per horsepower[lbh/hp])
The motor above can actually reach 0.38 BSFC intercooled and that's actually with some impressive power numbers to go with it. But it's also got to stay in the air for 30+ hours at a time and not refuel.
<- it's huntin terworsts... Elmer Fudd voice..
The point is it might be more efficient to make lower the drag of the supercharger on the engine than it would be to install an entire new forced induction system. You install a new header for a 10% increase in hp, the drag of the supercharger on the engine is using up to 24.4% of the engines power. If you could recapture even half of that, it would produce a significant gain.
