Originally Posted by
JHM2K
IIRC the Supersprint exhaust for the SLK350 was in the 70mm range (2.75") for the reasons of back-pressure. There is a fine line where any top-end gains are negated by the bottom-end losses.
Yes, but there is a big difference between NA and FI engines. The SLK350 needs to suck in the air the SRT-6's SC will force the air into the engine. Backpressure is much less of a concern with an FI motor and in the case of a turbo motor the less back pressure the better (the sooner the turbo will spool up).