DR.D NS- 2 EXHAUST PIPE Without a doubt the DR.D pipe produces the most power of any YZ250 pipe on the front side of the curve, and the NS- 2’s strong low end is mated to a very pronounced and impressive midrange. The downside of all that awesome midrange is that the DR.D pipe goes flat at 8000 rpm. This is 1000 rpm higher than the stock pipe, but 1000 rpm lower than other aftermarket YZ250 pipes. VERDICT: Since it is capable of pulling the next gear, which the stock pipe can’t do, you need to short shift, and then use the strong midrange to pull the bike like a tractor as opposed to a road racer. DIGITS: $239.95 (NS- 2 pipe), $139.95 (silencer)— www.dubachracing.com or (877) 382-2241.
SCALVINI CONE EXHAUST PIPE The Italian-built Scalvini is the most unique YZ250 pipe made. First, it is a cone pipe. Second, it is the most expensive YZ250 pipe. Third, it has a very linear powerband with a very smooth transition. VERDICT: Every test rider was impressed by how fluid the Scalvini made the power feel. Plus, it never suffered in the horsepower department on the front side. It was easy to ride, smooth from gear to gear and universally unimpressive. Its peak horsepower was 46. 92, but after peak, it fell off the map. It’s best suited to Novice and Vet riders. DIGITS: $279.00, $175.00 (silencer aluminum/carbon), $229.00 (silencer all carbon)—(909) 608-0082.
YAMAHA YZ250 TWO-STROKE EDITION
FMF FATTY EXHAUST PIPE Whereas the other pipes excel at one thing, the FMF Fatty is pretty good at everything. The workmanlike powerband makes it feel like it has the meatiest and most usable power. If it has a flaw, it is that it goes flat at the same rpm as the DR.D and Scalvini pipes. Every test rider wished for a little more boost on top. VERDICT: The FMF Fatty doesn’t require any tricks. You don’t have to short shift, you don’t have to play gun-and-run, and you don’t have to wait for the hit. You just ride it. That’s a compliment on the grandest scale. DIGITS: $229.99 (Fatty), $129.99 (Shorty silencer)— www.fmfracing.com or (310) 631-4363. ;
PRO CIRCUIT WORKS EXHAUST PIPE Make no mistake about, this is the most powerful YZ250 exhaust pipe built. It is the only aftermarket pipe with not only more over-rev but more ponies on top. It is the only pipe to crack 49 horsepower—and the only aftermarket pipe to crack 48 horsepower. VERDICT: Pro Circuit gets its big numbers by giving up low and mid in exchange for top. Below 7600 rpm, the Pro Circuit pipe is just average. After 7600 rpm, it has no equal. This makes it very exciting to race with, but that means that you have to pull the trigger. This is a Pro pipe. DIGITS: $249.95 (Works), $119.95 (R-304 Shorty)— www.procircuit.com or (951) 738-8050.