YFZ450 Pipe Shoot Out

[Midwest Trail Rider]

BY THE NUMBERS
We also wanted to get some hard numbers from each contestant, so we ran them all on the Dyno at the nearby K&N filter facility. We used a set of Carlisle slick tires mounted on the back of the YFZ to give a true rear wheel horsepower figure. Former professional racecar mechanic and K&N R&D technician Charlie Tissen operated the dyno. He performed three separate fourth gear runs for each muffler, and gave us the reading for the highest power producing run.

Between each run, we checked the quad?s engine and water temperature, and made sure the vehicle was operating at the same temps for each set of runs. Looking at the dyno graphs, you want to pay attention not only to peak number but the shape of the curve as well. A well-rounded curve will make the quad easier to ride with less shifting requirements. A very sharp graph, that falls off quickly after the peak, is not what you want to see.

You will see that on the YFZ, it makes its usable horsepower between 4000 and 10,000 rpm. It needs to be revved. For this test, five models looked very strong on the top side of the curve. The White Bros., FMF, DRD, and the Pro Circuit all held over 45 hp for well over 2000 rpms between eight and ten thousand. The Two Bros. wasn?t far behind. For lowend, HMF, LRD, DRD and the White Bros. had the best looking horsepower and torque numbers between four and six thousand.

RESULTS
Since one of the main points of this test was to focus on sound levels, we will start by eliminating the loudest. If a law enforcement officer were to check you while riding any of these pipes, you would likely pass. However, you better cross your fingers if you?re using the DG, Pro Circuit, White Bros. or the HMF. Hopefully these companies will go back to the drawing board and try to find a way to eliminate at least one decibel. Although these are great power-producing pipes, they will have to be eliminated from the overall at this time. The Two Bros. and Big Gun will get extra points for being the quietest.

In the power department, the Bills pipe gets the axe for low numbers. Although the LRD has the lowest peak numbers of the rest, it has great low-end numbers but just not enough to stay in the game. Dubach?s pipe and the FMF are producing the best numbers at the head of the pack and the ultra quiet Two Bros. pipe has tons of untapped potential. Unfortunately, the Two Bros. pipe is ultra expensive as well and has to be eliminated at this time. The same goes for the ESR product.

Looking at the remaining four contestants; the Big Gun, FMF, GYTR and Dubach pipes, we will eliminate the GYTR for being the low power producer and the most difficult to install. Big Gun was also elimimated for having lower numbers across the board than the other two. With only two (FMF & Dubach) remaining it?s time to pick a winner. With its low $310 price, easy installation, strong power figures and music to our ears sound numbers, the Dubach Racing quiet exhaust system is the winner of the Yamaha YFZ450 slip-on pipe shootout. Congratulations