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RarlyL8 RarlyL8 is offline
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Join Date: Jan 2000
Location: Huntsville, AL
Posts: 13,423
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Equal length primaries do the same thing for a turbocharged engine that they do for a normally aspirated engine; increase torque off-boost. The added value beyond that is the exhaust pulse timing is optimized at the turbin which increases efficiency. It also allows a slight bump in HP at the top end due to more optimized flow. A turbocharged engine will also benefit from smaller primaries than expected due to the velocity created. Primary pipes on the factory 934 were 37mm (1.45"). The SSI system will support 600HP.
I plan to dyno the 993 and SSI based systems and compare to the stock J-pipe configuration. It is really not correct to test in that manner because the exchangers are just one component of a system and may work best with other specific components. For our use though it is acceptable to test against a known common setup as that is what most folks will use. I don't expect to see any earth shattering differences as this is a medium power street engine.
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RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8
Old 01-02-2009, 01:47 PM
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