Speaking of 4-2-1 extractors, this is the WRONG WAY to do it on a four cylinder engine! A 4-2-1 system must have cylinders #1 & #4 joined up, and #2 & #3 joined up, then further down those two pipes join into one. The 4-2-1 system gives good all-round power, with no special power peaks or dips, while a 4-1 system give the best power at higher revs – At the expense of low end power.
For road, you’ll be best off with a 4-2-1 system on a four cylinder engine.įor high performance & race use, the only way to go is a 4-1 system.
