PRODUCT TEST: DR.D Yamaha YZ450F Exhaust System

2009 YZ450 EXHAUST: WE DIDN’T KNOW IT WAS SLOW UNTIL WE TRIED THIS PIPE

WHAT IS IT? An exhaust system for the 2008-2009 Yamaha YZ450F from the man who developed the Yamaha YZ400F, YZ426F and YZ450F.

WHAT’S IT COST? $879.95 (Ti/carbon), $779.5 (Ti/Ti), $679.5, (stainless/carbon) and $549.95 (stainless/aluminum)–(951) 808-4111 or www.dubachracing.com.

WHAT’S IT DO? Once the introductory thrill of ogling the downsized muffler on the 2008 Yamaha YZ450F is over, most YZ450F racers will want more power, improved throttle response and a less corked-up feel. The stock 2008-09 YZ450F is a very innovative muffler. It uses ice cream cone-shaped diffusers inside the muffler canister to reduce the energy of the engine’s pulses. The result is a quieter muffler than the year before (about one decibel), a lighter exhaust system (nine ounces) and a major loss of horsepower (over five horsepower at 6000 rpm). On MXA’s priority list, a muffler has three tasks:
ÿÿ (1) Make the bike quieter (97.5 dB is not all that quiet when you consider that the KTM’s all come in below 95.5 decibels (without the cones).

ÿÿ (2) Produce more power. The stock 2009 YZ450F muffler costs the big YZ-F both torque and ponies over last year’s model.

ÿÿ (3) Be as light as possible. The stock 2008-09 muffler is nine ounces lighter than the stock 2007 pipe, but even the most basic aftermarket pipe is as light.

ÿÿ (4) We think that the stock YZ450F exhaust system was a performance mistake. Most YZ450F riders will demand more oomph. That is where DR.D comes in. DR.D stands for Dubach Racing and Development and is owned by official factory Yamaha test rider Doug Dubach. Doug knows Yamaha four-strokes better than anyone on the planet, and naturally he was the first person that MXA turned to for a new exhaust system.

WHAT STANDS OUT? Here’s a list of things that stand out with the DR.D 2009 Yamaha YZ450F exhaust system.
ÿÿ (1) Performance. It didn’t take more than one lap to realize that Dr. D has done his homework. His exhaust system brought the YZ450F to life. It was better everywhere. The throttle response was lightning quick. The midrange rocked you back in the saddle. And, the top-end transition was seamless. In truth, we weren’t all that amazed. There has never been an easier exhaust system to improve on than the 2008 YZ450F stock plumbing. Building a better ’08-09 YZ450F pipe is like taking candy from a baby.
ÿÿ (2) Muffler design. DR.D’s D-shaped muffler can be ordered as a Titanium pipe with a carbon fiber muffler, titanium pipe with titanium muffler, stainless pipe with carbon fiber muffler, or stainless pipe with aluminum muffler. The price varies from $879.95 for Ti/carbon down to $549.95 for stainless/aluminum. All DR.D mufflers come with magnesium end caps.
ÿÿ (3) Weight: DR.D’s Ti/Ti and Ti/carbon pipes are one pound, eight ounces lighter than the stock Yamaha YZ450F system. Their $330 less expensive stainless/aluminum system weighs the same as the stock exhaust.
ÿÿ (4) Choice: If weight is an issue, go with the Ti/Ti system. If price is an issue, go with the stainless/aluminum system. MXA never recommends carbon fiber mufflers. They have a limited lifespan and are only for the terminally rich or pro riders who don’t have to pay.

WHAT’S THE SQUAWK? It is worth noting that apart from weight, there are no dimensional or performance differences between the most expensive DR.D pipe and the least expensive one.

MXA RATING

This pipe rocks. It makes the stocker feel like a mild-mannered WR450F by comparison.