In this economy nobody can afford to waste money on underperforming parts. And since our job is to report on what works and what doesn't, we gathered the most popular exhaust systems to see how they stacked up. Since we couldn't test every system for every bike on the market we chose the popular Kawasaki ZX-14 as the test mule.
With the big Kawi in our possession we rounded up 18 slip-ons and full systems and put them through an array of tests. Each system was weighed, dyno tested, measured with a decibel reader and evaluated for its fit and finish.
Deciding on an overall winner would have been pointless since everyone has a different idea of the "perfect pipe." Maybe you want the most power or the least weight, possibly you want the loudest-or even the quietest; you get the point. These are the straight facts so you can make your own judgment as to what's the best pipe for you. There wasn't a bad system of the lot; every unit increased power and cut weight versus the factory clunker.
Pop a cold one and enjoy the aftermath of over 20 hours, 70 dyno pulls and a whole lot of burnt hydrocarbons. Here's SSB's exhausting investigation.
*Note: All dyno runs were completed on the same dyno over the course of two days in nearly identical weather conditions using Chevron 91 octane fuel. Since the ambient noise of the dyno room was too loud to accurately meter exhaust sound levels, we listed the figures in + or - decibels over the stock system.
SLIP-ONS
Leo Vince SBK Midnight unLimited slip-ons
Weight with insert/open: 13.54/13.14 pounds
HP/Torque with insert/open: 163.1 HP/100.9LB-FT; 164.6HP/101.4LB-FT
DB with insert/open: +5/+11
Price: $679, +$100 for custom etching
Contact: leovinceusa.com
The Word: We opted for the midnight cans with the optional custom logo, but if that's too flashy for your taste you can always rock the standard Leo logo. These slip-ons installed without a hitch, cleared the bodywork and kickstand, all while making good power with only a marginal increase in sound. The quiet inserts did a good job of cutting sound without power.
Yoshimura R-77 Stainless/Carbon Slip-ons
Weight: 14.76 pounds
HP/Torque with insert/open: 163.1HP/101.5LB-FT; 165.7HP/101.9LB-FT
DB with insert/open: +6/+6
Price: $1,099
Contact: yoshimura-rd.com
The Word: The R77 slip-ons fit like factory and tied for the top honors in slip-on horsepower. Although heaviest in class, they're still over 10 pounds lighter than the stockers and only check in a few decibels louder. Sound quality was also impeccable, as was the finish and style.
M4 Retro Drag Slip-Ons
Weight: 10.08 pounds
HP/Torque with insert/open: 164.1HP/100.9LB-FT; 164.6HP/101.5LB-FT
DB with insert/open: +16/+19
Price: $651
Contact: m4exhaust.com
The Word: The M4 retro slip-ons had a unique look and sound all their own. On the dyno they were on the upper end of the spectrum, as were their loudest-in-test sound check of 19 dBs over stock when uncorked. At a hair over 10 pounds they were on the lighter side and installed in minutes, despite some necessary wiggling in order to clear the kickstand. If old skool drag-style pipes are your gig, the M4 slip-ons are a unique answer to your retro request.
Two Brothers Racing Black Series V.A.L.E Carbon Fiber Slip-ons
Weight: 10.02 pounds
HP/Torque: 163.4 HP/100.7 LB-FT
DB: +9
Price: $979
Contact: twobros.com
The Word: The new carbon fiber Black Series pipes from Two Brothers have a slick style and looked great on our red ZX-14. Fitment was great, save for some initial contact with the side stand that was quickly remedied with a little tweaking. Once set straight the TBR pipes fit great, made decent power and had a nice tone. TBR also offers many different can color combos.