16-09-13, 06:34 AM
(15-09-13, 11:33 PM)solorider link Wrote: generally a 4-1 will give an increase in the top end and losing out at the lower and midrange where a 4-2-1 will give better results in the low end and midrange with a smaller increase at the top end,
Generally being the key word here.
With the Gen 1 motor, it works the other way. A 4-2-1 (such as the Akra system) is a little better up top but not so good in the 3 - 4k rpm range. It's essential that a 4-2-1 for this motor has short secondary stage pipes and the primary headers can't be too large in diameter. That's why the Akra headers are tapered.
The Muzzy 4-1 system is better low down and loses nothing for the deletion of the EXUP valve. The key thing, though, is the design of the merge plate inside the collector.