Flex for an L4

[Donnie 1267]

I've got an L4 pipe I want too run on my KT100. Running a 1/5 mile track. Is 7.5 a good flex length for this pipe?

 

[sundog]

I'm guessing you don't have the L series header? Measure from the piston face to the end of the flex 7-1/2".

 

[Donnie 1267]

I do have the L series header.

 

[aracer50]

7 1/2 will get you going, tweek from there

 

[alvin l nunley]

An educated guess, but really only a guess, 28.375 from the piston face to the end of the converging cone. That's where my "SL" bullet pipe ran best. It was more of a top end pipe. The pipe was 20 inches and the header was 8 3/8. The RLV L4 used straight sided cones whereas my SL bullet pipe used spun cones, very similar effects.
The RLV website has all the numbers you need.