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kenikh kenikh is offline
3 restos WIP = psycho
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Join Date: Feb 2005
Location: North of Exit 17
Posts: 7,729
Twin scroll is a no brainer...seems every turbo set up for twin scroll has a spool threshold at least 500 RPM sooner than merged, non-equal length collectors. The ones that seem to do best are the turbos designed with segragated intakes inside the turbo all the way to the turbine, but as has been seen with the RarlyL8 headers, even merging just before the flange has benefits in keeping the pulse signature of the exhaust clean until the last possible moment.

Every turbo used in the latest breed of small bore Japanese turbo rockets use this technology to achieve big power and quick spool, even in 2 - 2.5L motors. I am glad to see this thinking bleeding over into Porsche-land. It has no downside.

The other thing that has been sorely missing until the latest breed of EMS is knock control. Properly set up knock control can give at least a half point bump in usable static CR...a huge benefit for off line response and low end boost pressure. Water cooling is an easy scapegoat to dismiss why the pocket rockets can run 9:1 CR and 30 lbs of boost...water cooling does have significant benefit, but the answer for air cooled 911 motors lies in between the 930 status quo and the newest breed of turbo cars. This thread is a great step in putting myths to rest.

Turbokraft is definitely doing it right and thinking of problems in terms of 2010, instead of thinking like it is 1992. Kudos!

- 1965 911
- 1969 911S
- 1980 911SC Targa
- 1979 930
Old 05-18-2010, 07:26 AM
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