Calling all SBP Pipe users

cyclepro101 · Aug 14, 2009

Just wondering at what spped does your powerband kick in at. I have been cutting the "J" pipe down in an effort to tune it but I dont want to go too far. I guess I have chopped about 2" off it now and the band cuts in about 39km/h. Thats the powerband not going from 4 cycing to 2 cycling. I get to about 40km/h and it just wants to take off and startes reving real smooth. As its a 66cc my plan is to bring the band down to kick in at the lowest rpm possible.
Also I run a 36t sprocket.

So what size engine u got?
what size sprocket?
and what speed does your band kick in at?

Steve

Ghost0 · Aug 14, 2009

If you want the power band at a lower rpm you want the pipe longer not shorter. The longer the pipe is the longer it takes for the pressure waves to travel through the pipe which equates to better timing at low rpm and more power at lower rpm's. With a shorter pipe the pressure waves take less time to travel the distance of the pipe which is timed better for higher rpm's and therefore produces more power in the higher rpm range.

For a single speed I think a 36 is pretty tall and your bike will not have much low end torque anyway. Now that you have shortened the pipe it has also reduced your low end torque. Maybe try a 40 which may keep your engine in a more suitable rpm range for your current set up.

cyclepro101 · Aug 16, 2009

Sorry about the mis understanding. I understand that these 66cc motors have good low power so by sortening the pipe I am getting it to rev higher. Ether way it has great power down low, but I dont run it flat out (WOT) much anyway. Also I run 1:100 Opti-2.
LOVE IT!

donuts31 · Aug 16, 2009

I got mine tuned for power just above idle. I need the ability to pull from a stop up very steep hills. The low speed torque is incredible and my top end is the same so I'm happy.

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Calling all SBP Pipe users

cyclepro101

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