Quote:
Originally Posted by SS_Firehawk
With Superchargers, there is a lot of blow through through the heads and makes it difficult to build pressure. Reducing the overlap and running a less aggressive profile will allow the SC's to get boost up quicker. Don't quote me, but I don't think turbo's have this same problem. It's also a big reason why long tubes weren't making the same power as a stock header because the heads and exhaust were too efficient. It made more power per lbs of boost, but not enough boost to make more power than the stock headers. I feel being able to control VVEL will be a big deal for supercharged cars. Maybe we can reduce overlap to increase pressure, and open it up progressively so it gets top end efficiency. Just a theory, but it sounds good lol.
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Yep, there should still be some advantages NA, but FI greatly changes optimal valve timing. The ideal angle will change significantly as you force a greater volume of air into the cylinder.
Essentially, as I understand it, you want just enough overlap for achieving peak torque -- wrong timing means you just lose boost, blown out before it has a chance to build peak pressure.
With turbos I believe you want as little overlap as possible, as you want to get exhaust gasses flowing as much as possible. I'm more familiar with SC's, so someone correct me if I'm wrong.