Some how I missed this... Thanks Roo!
Copied and pasted this from another thread that was started. This is from the designer of the pipe:
I want to give everyone on this forum an insight to PFP and the PowerFactor SJ Freestyle Exhaust system.
This exhaust system is designed to be used on superstock engine setup’s (800, 900, 1000, 1100). Over the last several years, many engine builders have been designing bigger freestyle engines, IE Stroke, Bore, Exhaust Valves, and Etc. The only piece that remains the same is the “B” pipe. Don’t get me wrong, the “B” pipe is a great all around pipe for stock and slightly modified engines, but it was never designed for maximum HP or Torque. It was originally designed to make a 20 hp increase on a stock Yamaha 701 SJ. On superstock engines the “B” pipe signs off quick. I’m not going into details, I will explain it in simple terms. It is about the powerband. Todays top freestyle riders are using the midrange to launch. Once you get into the midrange and rev out…..Hold on. It may take a little adjustment to get use to riding this powerband.
Design: The perfect pipe would be a straight pipe if you could fit into a ski. The more bends and the tighter the bends, the more HP you lose. There is no current dry pipe you can use that allows you to run exhaust valves because they go up and around the engine. The PFP pipe allows easy access to all engine parts and has minimal bends.
Fuel Tank: You can use a 2 gallon fuel tank on the Yamaha SJ. This allows for 30-40 minutes of riding time. If you are making a lot of HP, any rider will tell you after a 30 minute session, you need a break. It takes 30 seconds to refuel. You kinda get use to it. It is also about the weight. Three to four gallons of fuel is a lot of weight.
Engine Tuning: Anytime you make more HP, you have to make the appropriate adjustments, IE Ignition Timing, Fuel, possible Impeller changes, ETC. Every superstock is different according to the engine builder. Remember everything has to be right from the time the air enters the flame arrestors to the time the exhaust exits the rear of the ski.
Production: PFP exhaust, are manufactured at Factory Pipe. We have never had a failure after running these exhaust systems for 3 years
Cost: No they are not the cheapest pipe. Anybody in the production business will tell you it’s about qty. PFP is not producing 1000 at a time. We manufacture 50 at a time.
Dyno: I would not even think about dynoing a “B” pipe on a superstock engine. Been there……done that….10 years ago. The dyno is a great place to develop a new tune spec for a pipe, but you cannot duplicate the way it runs on the water (off idle and mid range). You have to adjust the tune spec for the powerband you want “on the water” Bottomline. Let the ride speak for itself.
I did not write this to start any arguments. Everybody is entitled to their own opinions. I am only speaking from my own experience.
I want to thank every aftermarket company (X-metal, EME, Waterdawg, and all others) for contributing to future of freestyle and freeride. The sport is moving in the right direction.
PowerFactorProducts.com website is coming soon.
Mark
When defying gravity…………..Horsepower to weight ratio