Evaluation: Roadhouse Brand Classic Series Exhaust, Factory Pro Jet Kit, & Thunder Air Kit for Kawasaki Vulcan 1500 Classic Motorcycle

With the versatile Roadhouse Brand pipe, a Factory Pro jet kit, and the easy-breathing Thunder intake system, Kawasaki's 1500 can flex its muscles. From the December 1998 issue of _ Motorcycle Cruiser _ magazine. ** By

In a time when most aftermarket exhaust manufacturers sell only two-into-two exhausts for V-twins, Roadhouse Brand has released its two-into-one Classic Series exhaust system. Several features distinguish the Roadhouse exhaust from other brands. First, the 2.25-inch serrated stainless steel heat shields provide full-length protection from the 1.5-inch headers, giving the pipe a vintage look. The long chromed canister leaves room for large saddlebags and gives the pipe a distinctive appearance. Adding one of the four optional tips ($70-90) makes the system even more unique. It is priced at $500.

Mounting the Roadhouse Classic exhaust took approximately one hour; removing the stock system was the most difficult part. Roadhouse's clearly written instructions feature photographs of key elements of the installation process.

Thumbing the starter button elicited a throaty tone from the pipe, without being overly loud. The bike's throttle response was generally as good or better than stock. A trip to Bartels' Dynojet dyno revealed a jump in peak horsepower from 55.1 at 4250 rpm to 59.3 at 5000 rpm. The Roadhouse pipe provided our Classic with better power output from 2500 rpm and up. Peak torque jumped 2.5 foot-pounds to 79.9 at 2750 rpm. Adding the $65 Roadhouse jet kit (developed by Factory Pro Tuning) produced fatter midrange power at the expense of a 0.4 peak horsepower. The torque numbers increased to 80.2 foot-pounds at 3000 rpm, and were higher than the pipe without the jet kit all the way up to 4250 rpm. The pipe/jet kit combination felt slightly smoother out on the road.

Just over 100 miles after fitting the Roadhouse pipe to the Classic, the serrated stainless steel heat shield began to yellow at the bend in the pipe about two inches from the rear cylinder manifold. Roadhouse anticipated this problem and provided us with a bottle of its Classic Exhaust Stain Remover & Cleaner ($10). A few wipes with a clean rag moistened with the solution returned the stainless to mint condition. The slight yellowing on the forward edge of the chromed canister improved, but the change was not as dramatic as on the stainless section of the pipe. Still, we were so impressed with the cleaner that we tried it on some badly blued stainless and chrome pipes we had in our shop. While the cleaner made a more noticeable difference on the stainless, neither part returned to its original condition. Moral: Apply this cleaner to yellowing or bluing parts early and often.

After a few hundred miles, the Roadhouse system became distinctly louder. Roadhouse told us our pipe was one of the early production pipes that did not receive enough overlap on the fiberglass packing in the canister. Pipes currently being shipped should not suffer from this problem, though all glass-packed pipes do need to be repacked periodically. Although it never backfired while we were riding, the Roadhouse pipe frequently emitted a little poof, pop, and occasional bang when the engine was shut off after a long ride. We also heard the sound of dragging metal more frequently when making right-hand turns. Although we never touched the pipe down hard enough to lever a wheel off the ground, riders who cruise corners at a spirited pace should be forewarned their floorboards will no longer touch down first.

Once we had the freer-breathing exhaust system installed, we decided to ditch the restrictive stock intake system. Thunder Manufacturing sent us its $229 Thunder Air Kit. The machined billet aluminum bracket attaches to the stock carburetor via the stock intake boot, allowing the airbox and assorted clutter to be removed. A breathy seven-inch K&N; filter keeps the intake system clean with minimal interference to the air's velocity. We'd suggest popping for Thunder's optional $79 chromed, billet air cleaner cover to get rid of the cheesy, stamped-metal K&N; filter cover. Other Thunder options include an oval K&N; kit and a Hyper Charger adapter.

While the Thunder Air kit doesn't ship with a jet kit, Thunder Manufacturing recommends a 170 jet and a needle setting of three notches up from the bottom, with one shim underneath. A quick call to Factory Pro Tuning had a jet kit (part #CRB-K99KN-2.0) in the mail to us for $65. Thunder Manufacturing has informed us a 170 jet (but no needle) is now included with the Thunder Air kit. The company says most customers already have jet kits installed and can use that needle.

We had removed the airbox system on an earlier model Classic when we tested aftermarket carburetors, so we thought we were familiar with the potential power gains. But we weren't expecting the jump provided by the Thunder Air breather-equipped stock carb and the KTRIC throttle-positioning sensor system. Horsepower peaked at 64.0; torque at 85.6 foot-pounds! Both horsepower and torque figures surpassed the pipe/jet kit/airbox system from 2500 rpm to redline, and power delivery was seamless.

In conclusion, the combination of the Roadhouse exhaust system and the Thunder Manufacturing intake kit made riding our long-term Vulcan Classic even more fun than when it was stock.


Factory Pro Tuning
21 A/B Golden Gate Drive
San Rafael, CA 94901
(800) 869-0497, (415) 721-4964

Roadhouse Brand
29395 Agoura Road, Suite 105
Agoura Hills, CA 91301
(818) 707-1276

Thunder Manufacturing
4210 N. 39th Ave.
Phoenix, AZ 85019
(602) 269-5033

For additional evaluations of, comparisons of, and shopping advice for motorcycle gear and accessories, see the Accessories and Gear section of MotorcycleCruiser.com.

The Roadhouse pipe and Thunder Air intake filter, in conjunction with a Factory Pro jetting kit, dramatically increased the performance of our 1998 Kawasaki Vulcan 1500.
_Many motorcycle owners assume that a pipe is the simplest route to more power, but a freer-breathing intake is usually a better power maker than an exhaust system. Fitting the Thunder intake system cost a lot less than a pipe, added more horsepower and increased torque more than twice as much as the pipe change—and that was after the gains from the pipe had already been realized.
Thunder's optional billet air cleaner cover would bring the revised intake in line with the finish quality of the Roadhouse Brand exhaust system.