Chaparral Motorsports Pro Works Episode 2: Dr. D Exhaust System Install
One the best ways you can improve the performance of your dirt bike
is to swap the stock exhaust system with either an aftermarket
muffler or full system. There are many manufacturers such as
FMF, Yoshimura, and Pro Circuit that make
quality exhaust systems for both 2-stroke and 4-stroke dirt bikes.
However, for the
Chaparral Motorsports Pro Works project bike, the in house
performance guru, Larry Brooks chose to go with a full system from
Dave Dubach of Dubach Racing Development, aka Dr. D.
With years of racing experience backed by plenty of on-bike testing for the Yamaha Factory Race Team, Dr. D knows how to tell when something is working and when something is working really well. He's used his knowledge and background to create a line of exhaust systems that are made from quality materials and offer great bolt-on performance.
For this bike, a 2015 Yamaha YZ 450F, Larry opted to go with the Dr. D [mageProductLink sku="drd-7571"]NS-4 complete exhaust system[/mageProductLink], which will further enhance the performance attained with the Bazzaz EFI components that were installed in a previous post. The NS-4 system (available with either a aluminum or carbon fiber muffler) offers a reduction in weight over the stock exhaust.
The first thing many will notice about the DR. D pipe is that it mimics the routing of the stock exhaust in the fact that it completely wraps the engine-which makes sense considering Dave's long history testing for Yamaha. The head and mid pipes are comprised of 304 stainless steel and come in at nearly 1 pound lighter than stock. It's at the tail end however that the real weight savings come into play as the carbon fiber muffler assembly is about 3 pounds lighter than stock--the aluminum muffler still lightens the overall load but not as much as the carbon fiber. Along with being a much lighter system, the way the exhaust wraps around the front of the engine helps keep the weight of the bike centralized for excellent handling characteristics. And when you think about it, shaving four pounds off a 245-pound dirt bike can make quite a difference in handling, and overall performance.
This system, as with all Dr. D exhaust systems, has been track tested to improve hit, delivery, and pulling power with noticeable performance gains. The assembly features TIG welded construction for structural integrity and a clean looking finish. Tucked neatly into the end of the carbon fiber muffler is a magnesium end cap which has been riveted in place for increased durability. The internals of the muffler features a stepped and perforated core, while removable bolts at the inlet cap enable removal for easy repacking. Speaking of packing, inside the muffler features roll style packing to help extend the life of the material.
As seen in the video above, installing the Dr. D pipe is a pretty straight forward process, you just need to take your time and carefully manipulate each piece of the exhaust system into place.