OK, so I was just sittin there thinking about cars, when I had the most random idea. I don't know if this would work well, or even at all, but you never know. It's the same idea as a supercharger, but for the exhaust gasses instead of the intake gasses. You would have a belt running to a blower that was connected somewhere along the exhaust system. Of course, you would have the blower set up to blow air out of the engine, not into. This would create a vacuum between the blower and the engine, and when the valves opened for the exhaust cycle, the exhaust gasses would actually be sucked out of the engine instead of pushed out. I'm not sure what effect this would have on performance/efficiency, if any. Just a random thought I had that I thought I'd let you play with. Enjoy...

 

I think it would rob more power than it could make...

 

Probably true, but if you could somehow get around the power robbing belts, what kind of effect do you think it would have, if any?

 

it would scavenge the hell out of the cylinders. it could either raise the VE a lot, or it could cause it to suck fuel through the intake valve and out the exhaust valve during the overlap. so it could go either way. should be good for power, but i doubt it would be good for economy. or emissions.

 

Another crazy idea - Have a real supercharger, and the thing I was talkin about above, and maybe you could have a cam made that has little or no overlap. I'd be interested to see what would happen.

 

youd still need overlap to make it worth it. it might be good for racing, but i think it'd be bad for the street.