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Old 02-07-2012, 08:28 PM   #644
Dimman
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Quote:
Originally Posted by serialk11r View Post
Okay yea so I got it wrong, it's not to increase the overall pressure, but to change the way the exhaust wave reflects back.

So I have a question since I'm too lazy to crunch a few numbers, exhaust scavenging effect on a 4 cylinder comes from the cylinder firing 180 degrees after right? So with a twin scroll turbo you essentially eliminate exhaust pulse interference effects?
With wave scavenging the primary tube reflection can 'self scavenge', same with steps. Secondary tubes can too depending on their length, and looking at total exhaust length, the atmospheric return looks like it will be closer to the 180 cylinder. Inertial/gas flow scavenging would be for the 180 cylinder.

Edit:
Found Yamaha's explanation on their site:

http://www.yamaha-motor.ca/technolog...oup=M&tech=EUP
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Last edited by Dimman; 02-07-2012 at 09:37 PM. Reason: Edit
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