ORIGINAL: Flyer95
I have one on my Irvine 53 and it works great. Fast throttle response and very good peak rpm[sm=thumbup.gif].
Irvine 53 on a pipe turns a APC 13x6 @11500-12000. I have never tried the stock muffler but I guess the rpm would drop down below 10000rpm.
APC 13x6 12000 with an Irvine 53?[X(] Are you sure you did not mean a 12x6? Yes a pipe is good for a lot, but this much?[&:]