Sturdy, stylish performers for pennies on the dollar
Last summer, we tested a DanMoto slip-on exhaust system on our Literbike Lust GSXR 1000 project bike. Following a full season of use that included a big crash, we concluded that this setup was well made, sturdy and functional. Best of all, our dyno experts at Valley Racing, in Beecher, Illinois, liked the DanMoto system as well, scoring it equal to a dual-muffler Leo Vince system that cost five times as much. In that article, we declared, "DanMoto has built a racing exhaust that makes excellent power and will withstand the rigors of racetrack riding, which sells at a price low enough that you won’t be heartbroken if you destroy it." Our one negative comment was that the product lacked style, but we were more than willing to accept that fact in light of its exceptional low price. Now, with their JISU muffler, DanMoto has followed an industry trend toward the tapered, angular look that is all the rage in exhaust lately. The result is a quite visually appealing product, which is still priced low enough that you can dare to risk using it at a trackday.
Quoting from our 2011 test of DanMoto's round muffler, "There’s nothing oval, conical, milled or pressure-formed going on here. In short, a DanMoto exhaust is functional, not fancy." Apparently, the company took our words as a challenge, rather than as the compliment which we'd intended. (We're imagining company founder Danzhou Zhang screaming, "Not stylish? NOT STYLISH? WE'LL SHOW THEM!") The result is this new offering, which seriously ups the ante appearance-wise over their round product, yet only increases the price of a system by TEN BUCKS. You'd better believe we were on board instantly when DanMoto asked us to do another test.
"JISU" is the Chinese word for motorsports. The muffler that bears this name is hexagonally shaped and is also symmetrical, which means that a pair would look cosmetically identical on a bike which carries one muffler on either side. The baffle and end caps of each unit are constructed from tig-welded stainless steel, while the shell is made from anodized aluminum. When sold as a slip-on system, its adapting pipes are also of stainless and come equipped with any required clamps or springs necessary for installation. Buyers can opt for either a black or silver finish to the muffler's shell. The clamping bracket is a stainless steel strap with a rubber protective strip.
DanMoto's way of doing business is to offer customers three styles of muffler: the classic round shape that we tested last year, a MotoGP-inspired titanium trumpet and now the JISU shape. All are available with an adaptor kit to fit the product to your motorcycle. Price varies by model and number of mufflers but a standard, single muffler Japanese bike falls into the $125-$135 price range.
The V-Twin Test
Our GSXR tumble of last year thoroughly convinced us that DanMoto builds tough, functional products. This time, we decided to really torture them in an application that's known to destroy inferior offerings. We installed a set of JISU mufflers on associate Steve Pallela's Aprilia Mille race bike. This machine regularly sees competition and has a high compression, overbored motor that burns race fuel. V-twin motorcycles are notorious muffler killers. Their huge, thudding sonic pulses and coarse vibration are much more destructive than the smoother, sewing machine buzz of a four cylinder. It's not uncommon to see twins explode or crack their muffler shells under racetrack abuse, but we've observed no sign of weakness or failure in the pair of JISU silencers we tested, even after half a season of trackdays and racing. Their sound is deep and beautiful, while their ability to make horsepower left Steve's engine builder very happy.
Ordering A La Carte
With Pallela's Mille, we had a very specific and unusual request. This bike was fitted with a highly efficient Akropovic two-into-two full-race exhaust system, which is acknowledged by Aprilia tuners worldwide to be the best available for competition use on this model. The system's original pair of titanium mufflers was ruined from crashing and replacements would cost $800 each! The problem was, since we already had a complete exhaust and only needed mufflers, how could we know which ones would fit our pipes? Happily, DanMoto was more than willing to supply us with just the mufflers. We merely needed to let them know what inlet size we required. Their standard offerings are ID 60mm, ID 2", ID 45mm, ID 63.5MM and a few more. Mufflers are sold for approximately $100 each, depending on size and style. This wasn't a one-off deal, either. The company will sell just a muffler to anyone and adjust the price accordingly. All you need to do is use the "Contact Us" function on the DanMoto website.
Needless to say, if you're ordering mufflers from DanMoto and fitting them to a different brand of exhaust, there will be some fabrication required. On Pallela's bike, the muffler inlets had to be expanded a bit to slide onto the existing pipes. Most any muffler shop can do this if you bring them the pieces. We're not fans of the retaining strap supplied by DanMoto. You'll need to make the flat strap fit around the five-sided muffler, which is not a project for beginners. Additionally, Steve experienced melting of the rubber insulator strap on his Aprilia, just as we had last year on our GSXR system. The cure, as we discovered in our last test, is to make your own insulator from header wrap. To be fair, a street system would never run as hot as one you use at the racetrack and thus probably wouldn't have this issue, but since other manufacturers have sourced the right type of rubber, it would be nice if DanMoto could do the same. (Just before post time, we received an email from the company which announced that the rubber strap in question is in the process of being converted to high-temp resistant silicone based rubber across the DanMoto product line.)
Once again, DanMoto has come up with a low cost winner. Their JISU muffler is strong enough to handle the destructive vibes of even a highly built race motor, it looks great and most of all, is extremely inexpensive. In our 2011 test of the round muffler, we'd suggested, "At this price, it would be pretty easy to justify the purchase of a second DanMoto to keep with your spares." This advice still holds true. In short, the new JISU system is everything we liked about previous DanMoto products in a more stylish, modern looking package and best of all, it's still priced right. For racetrack use, these mufflers are the smart choice.