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RarlyL8 RarlyL8 is offline
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Join Date: Jan 2000
Location: Huntsville, AL
Posts: 15,037
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Quote:
do the bigger ports increase turbo lag?
Sizing needs to match other aspects of your build/goals. SC/Carrera heads are a nice bump for the 930 as they are not so large as to significantly influence lag but larger than the smog ports of the 930. For optimal reduction of lag the port needs to be large enough to support your power goals but no larger. Cams need to focus on torque, such as the SC grind. Header design is critical, the primaries need to be no more than 1mm larger than the port (laminar flow) and reduce volume by the time they reach the turbo (velocity). Equal length is best if possible, at the correct pulse harmony for peak torque/power. When the system is tuned everything works together.
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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 07-25-2019, 06:31 AM
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