Introduction · Stock System · Cobra · DG · Samson · SuperTrapp · Two Brothers · V & H · Raw Numbers · Comparison Charts
"...almost one-fourth of the people...said they planned to buy an exhaust system for their bike in the next year...decided to see what pipes were available for our long-term Vulcan 1500 Classic. We wondered how these pipes would compare to each other, how well thought-out they were, and if they would fulfill the conflicting demands of good power and good citizenship.
White Brothers of Yorba Linda, California, was kind enough to provide its DynoJet dynamometer for the horsepower numbers, and R&D Mechanic Dennis Emerson for the wrenching, installation advice, and expert commentary. We timed each installation and rated it on a scale of one to five, with five being a perfect score. Next, we ran the bike on the dyno. All the pipe manufacturers, with the exception of Cobra (which sells its own jet kit), recommended using a DynoJet jet kit with their pipes. We tested each pipe with the jet requested.
Sound levels were tested on the dyno at the AMA standard distance of 20 inches at a 45° angle from the pipe opening with the sound meter facing away from the pipe, and the engine at a constant 3000 rpm. The drive-by sound test was taken at a distance of 12 feet with the Classic at a constant 45 mph in second gear, or about 3000 rpm. Decibels are calculated on a logarithmic scale, which means if a sound increases by 10db, it's three times as loud. An increase of 20db translates to almost 10 times louder.
...established 104db as their maximum acceptable sound level for street use, we used the same limit. Though it's a bit arbitrary, going above that level guarantees that you're making enemies for motorcycling every time you ride.
Allof the pipes weighed in less than the stocker -- some by as much as 20 lbs. All made more power. All were louder than stock, but some were unacceptably so. Most of the headers blued, a problem caused at least partially by running the bike at full throttle on the dyno immediately after installing the pipes. Finally, some of the pipes limited ground clearance.
If the power increases these pipes offer aren't enough for you, Emerson suggests removing some of the intake plumbing and adding a K&N air filter.
The factory exhaust system has the unenviable job of meeting EPA requirements while providing an appealing exhaust note, apprearance and performance. Only in the power department does Kawasaki's compromise make itself noticeable. However, the huge performance gains of yesteryear are no longer achieved by smiply bolting on a pipe; OEM units are too well designed. Aftermarket pipes now offer more moderate gains, the opportunity to customize, and instant weight loss. At 33 pounds, 8 ounces, the stock pipe is a porker. Much of this comes from the expansion chamber under the swingarm.
To see how much power came from the pipes and not the jet kit, we ran the stock exhaust with both the stock and DynoJet jets. The DynoJet kit yielded 1.2 hp (49.3 peak) over stock jets, and improved throttle response, as well.
One note about removal: If the system is hot (and who would remove a hot pipe but people who have six more to put on and test), you run the risk of shearing off the studs connecting the headers to the expansion chamber. The complexity also makes it a bear to put back on.
Initially, we wondered why Cobra would sell the Classic slash-cut exhaust system with only three little heat shields, but Cobra has since expanded the pipe kit to include full-coverage heat shields, which were formerly sold as an option. The full shields protect the rider from heat and hide the top part of the header where chrome pipes are prone to bluing.
Installing the Cobra pipes took time because of tight clearance between the rear cylinder's canister and the rear axle. After trying several methods, we bent the pipe's bracket outward to gain more clearance. Cobra provides a bracket to move the voltage regulator (which hangs under the swingarm to hide the ugly expansion chamber on the stock pipe) to a less-visible location, cleaning up th eleft side.
The Cobra system ranked in the middle of all the categories we tested, providing a decent power increase without crossing over our maximum streetable loudness. Combined with a Cobra-assembled DynoJet kit, the Cobra pipes produced a maximym of 51.8 hp and 103 db. The only difference between the kits is Cobra's DJ132 main jet versus DynoJet's DJ136 main jet.
The DG Hard Krome staggered duals were the easiest pipes to install, bolting on in a mere 10 minutes. The double-wall pipes have a built-in heat shield, which protects both the rider and passenger from burns. Observers liked how the thick pipes added to the Classic's fat look, tying with the V&H pipes in our garage beauty pagent. One miscue in the pipes' fit and finish was that the welds between one pipe's header and canister were not ground down prior to chroming, leaving an ugly seam. While tipping the scales at 20 lbs 8 oz, it was the heaviest of the aftermarket pipes, but it still shaves over 13 lbs off the Classic.
The DG pips were the least powerful of the aftermarket units tested, making only 49.0 hp, a scant 0.9 more than the stock pipe. Being more restictive than the other pipes we ran with the DynoJet kit, the DG pips would benefit from additional jetting work to bring out more power. Incorporating an internal tapered head pipe which gradually funnels into 2.5" diameter tubing, the DG pipes' 99db reading earns it the good-citizen award for the test.
Although we asked all six of the exhaust-system manufacturers to send us fishtail-style mufflers, Samson was the only manufacturer to actually send one. Unfortunately, Samson may have been penalized in the loudness comparison as a result. Pushing the sound meter to 107db, the Samson exhaust pipes tie fo rworst in the sound department. These pipes are too loud for the street and were only ridden for photos and then removed. Delivering 51.7 hp -- middle of the road in this comparison -- we expested more output from all the racket that these pipes produced.
Installation was straighforward and quick, even with the spartan instructions. Be sure that you have American tools (1/2" and 9/16" wrenches) becuase no metric bolts are supplied. When viewing the pipe from the side, people either loved or hated the pipe's long skinny look, which was accentuated by the lack of a heat shield. However, most agreed that the fishtails looked cool from behind the bike. Optional head shields are available from Samson.
Except for technical problems in our first day of dyno testing, the SuperTrapp exhaust wouldn't have arrived in time to be included. Arriving late, these pipes exhibited typical pre-production problems: visible welds, no heat shields, brackets that didn't fit. One header was about 2.5" too long, and both headers had to be modified slightly to seal leaks between the headers and canisters. The pre-production bugaboos made installation time the longest of any pipe here.
The stainless-steel system yellowed immediately, but we don't expect the production units to suffer from this problem. The pipes feature the SuperTrapp megaphone desigh that people either love or hate. The droopy lower canister dragged easily.
Despite all the problems, the SuperTrapp Street Cruiser system, which runs 12 disks per canister, put out 53.7hp -- just 0.1 short of the best -- and stayed within our noise limits at 102db. Installing additional disks would presumably yield more power and more noise. Of course, the production version may be even better.
Our Two Brothers slash-cut duals were the first set the firm built for the 1500 Classic and were rushed to reach us in time for this test. As a result, they suffered from many of the problems a first-production piece has. No instructions were included, but we've been assured that instructions will come with the pipes sent out to customers. All of the mounting bolts were too long. Flange nuts were not included. The middle bracket of the font pipe could not be held in place with the stock bolts, but Emerson said he didn't think the bracket was necessary.
The Two Brothers pipes produced the most horsepower, delivering 53.8 horsepower at 4500 rpm. However, the pipes also tied for the dubious honor of being the loudest even though the exhaust note never felt as extreme to our ears as the Samson pipes. Nonetheless, at a roaring 108db, these pipes are much too loud for the street. Remember, if a pipe is so loud that you don't want to open the throttle for fear of a ticket, you can't use the extra power.
The V&H Classic Duals came with no less than five stickers plastered on them warning that ground clearance may be reduced. Ironically, we didn't drag these pipes when riding. Installation was relatively glitch-free, but we did need to suppply our own flangenuts for the headers. The pipe clamps are thinner than stock, causing the stock, capped flange nuts to bottom out before the clamps were tight. Relocating the voltage regulator under the swingarm was a bit time consuming, but certainly cleans up the left side of the bike. Since the relocation is for purely cosmetic reasons, a note stating the optional nature of the relocation might be helpful.
In our garage sampling of opinions, the V&H pipe tied as the best looking of the bunch. The powerful VHR pipes scored a solid 52.5hp -- near the top of the class, and its 102db rading placed the pipe in the stree-reasonable category.
|Stock||Cobra||DG||Samson||SupperTrapp||Two Brothers||Vance & Hines|
|Type||Staggered dual||Classic slash-cut||Slash-cut staggered dual||Fishtail||StreetCruiser system||Slash-cut duallies||Classic duals|
|Weight||33lb 8oz||12lb 9oz||19lb 0oz||10lb 10oz||10lb 13oz||15lb 9oz||21lb 14oz|
|Install Time||1 hr||50 min||10 min||35 min||2 hr 30 min||45 min||1 hr|
(20" / Rolling)