I ask this here, because you guys will have a more objective answer, because results matter more to you. From your observation how do these type of expansion chamber perform. Also how dependable do they seem to be.
http://www.bikeberry.com/engine-kit-parts/performance/expansion-chamber.html
I have seen 2 types of those banana pipes, one goes rite on and clears the BB, the other is too fat and hits the BB and pedals.
I don't know which one that is.
One tip is you can elongate the mount holes in the pipe if you need to twist the pipe in a bit to get it to clear everything.
As for the long high straight one I was glad to get rid of it. If it wasn't burning my inner thigh it was a heat source between my legs for very little gain.
Though the right size banana pipe works OK and it's easy to install I like the Sick Bikes pipes for the best performance gain.
They are a pain in the butt to install but allow you to be creative and they are *tuneable.
They are generally mounted like this.
But you can route them like this and keep the fat part of the pipe away from your nad's.
Or even mount it like this and throw a big glass pack on the end and make it sound more like a Harley than a weed whipper ;-}
It also helps to understand how a 2-stroke motor works and why an expansion chamber is like a reverse turbo-charger. Just follow the green gas/air mix
*tuneable:
An Expansion Chamber Exhaust is only as good as the pipe between the cylinder and fat chamber. The object is to get all the spent fuel out of it so it is just filled with the unburnt fuel and the right length to allow as much back into the cylinder as possible before the port closes and it fires.
The SBP pipes straight copper pipe piece is how you tune it to the motor.
It is the right length for a 48cc motor, cut it about in half so the two 45 degree copper pieces snug up over it for a 66cc.
Regardless get an Iridium plug, the best $8 you'll ever spend especially with an X-chamber.
I hope that helps ;-}
