I think the preliminary info on the Dax Hi perf pipe showed no real performance gains...I forget who did a review on it but if you do need a muffler it might be a good replacement....For true high performance you'd need a tuned pipe.
I have the DAX Hi Performance pipe and I am getting the same speed as my original pipe, the difference is I went from a 36 T sprocket to a 40 T sprocket. So in reality it increased about 2 to 3 miles an hour. Also with my original pipe I was having to slightly choke the bike in the lower speeds to get good acceleration and un choke after 25 to get up to 32, (this using 2 different carbs). With the new pipe it rolls right up to 32 with smooth and better acceleration. The clearance is close on the peddles, may have to do a little bending.
I did the DAX mod and I showed a renewed difference. But then my exhaust was littered in black tar. I have to say when you can make your exhaust breath that's a good thing.
Even on my truck I needed an after cat exhaust but it's all too expensive. So for 30 bucks I had a muffler shop simply weld a straight pipe from the cat and exited out to the side with one 45 degree bend.
No muffler. No bend over the rear axle.
It's just a tad louder if you can believe that but performance improved vastly. I had this miss felt like not getting enough fuel before this mod,now it's just gone.
Sorry for derailing a bit but basically the louder your exhaust,the free'er it's breathing.
I just put this on. I couldn't believe the impact my new pipe made on my low and especially mid range.I would definitely recommend the new Santa Cruz Scooter Works pipe! you can get one from pipelyne in SAN Jose
W31 is a Olds motor found in many cool 442's and some F85's for those that need ta know. Hey john... I have a safari wagon w/a W30 455...I even got the red wheel wells in it. Anyway..... back ta bikes, sorry guys.