An exhaust upgrade is often the first addition to any sportbike but even slip-ons aren’t cheap and the options are numerous so choosing the right one for your bike and budget is tough. Exhaust manufacturers claim big gains with their systems, but how do you really know the truth behind those claims? Simple, you let SSB do the dirty work. While we’d love to dyno every system for every bike, that’s just not possible, so we picked two popular models: a 2012 Suzuki GSX-R1000 for the full systems and a 2012 Kawasaki ZX-6R for the slip-ons.
Each system was tested on the SuperFlow dyno at Gene Thomason Racing, then weighed on the scales, evaluated for fit and finish, and finally measured with a decibel (dB) meter at wide-open throttle (WOT) and at a steady 5,000 RPM cruise.
The dyno sessions were done over the course of two days—all of the ZX-6R slip-ons were completed on the first day and the Gixxer full systems on the following to insure weather changes wouldn’t give any advantages to a given system. A Bazzaz Z-Fi and Z-AFM Self Mapping unit were also installed on the Gixxer to create a custom map for each full system with a preset AFR of 13.5:1. While certain systems might like a different air/fuel ratio (AFR), we wanted to make it fair for all of the competitors. All dyno pulls were done with Shell 91-octane premium fuel.
Inside the noisy dyno room it was impossible to get an accurate dB level due to the overwhelming roar of the fans and the rear tire spinning on the drum so we noted each system’s sound levels in a + or – over stock: The louder the system the higher the positive number and the quieter the system (no system was quieter than stock) the lower the number.
Selecting an overall winner is meaningless since everyone has an idea of the perfect exhaust. So we’ve listed the cold hard facts so you can be the judge, while also noting the leaders in each category. Kick back and enjoy our exhausting shootout that took two days, 26 hours of dyno/install work and over 130 limiter-bouncing dyno pulls. Welcome to SSB’s Second Annual Exhaust Shootout.
2012 ZX-6R Slip-Ons
* Retains Catalytic Converter
A full system is nice, but expensive. For the price of those pipe-dreams you can get an undertail, windscreen, levers, tank protector, frame sliders and a slip-on.
Team Green’s middleweight was selected for the marathon of slip-on testing since it’s been out for nearly five years and is a popular street choice. It baselined at 109.1 HP / 43.9 LB-FT.
We divided the categories into two: the systems that retain the factory catalytic converter (cat-back systems) and those that don’t (cat-delete systems).
Despite the differences—small to big, shorty to full, cat to no cat—the spread in power was just undertwo HP and four pounds from lightest to the heaviest.
VANCE & HINES CS ONE BLACK STAINLESS SLIP-ON
Construction: Stainless steel muffler and piping
Weight: 4.18 pounds
HP/Torque: 112.2 HP/ 44.3 LB-FT
DB at WOT: +9
DB at cruise: +5
Fit & finish: 10
The Word: Several years ago the CS One brought V&H back from a brief sportbike hiatus. Installation was OEM tight and the black beauty looked at home on the Green Monster. Its fit and finish are as good as anything from overseas. We awarded the CS One “Best Bang for the Buck Slip-On System” because it showed well on the dyno and scales and emitted a deep, mellow tone all while looking like a piece of streetbike jewelry. The CS One is available in matte black ceramic and polished finishes in case you prefer bling over brawn.
YOSHIMURA R-77 CARBON/STAINLESS SLIP-ON
Construction: Carbon fiber muffler and end cap, stainless connecting pipeand piping
Weight with insert/open: 5.62/5.98 pounds
HP/Torque with insert/open: 110.5 HP/ 44 LB-FT; 112.6 HP/ 44.3 LB-FT
DB at WOT with insert/open: +5/+6
DB at cruise with insert/open: +4/+5
Fit & finish: 10
The Word: Polished describes the R-77 system, as it fits like factory, sounds fantastic and made the most power of the cat-back systems. Its fitment is factory fresh thanks to details like a billet heat-shield and the quiet insert not only works admirably well, but it doesn’t rob too much power in the process.
It can be had in multiple muffler styles: stainless steel, carbon fiber or titanium so finding one to match your bike won’t be an issue. It is heavier than some of its competitors but made the most HP out of the cat-back systems tested.
LeoVince GP Pro stainless slip-on
Construction: Stainless steel
Weight with insert/open: 4.88/ 4.54 pounds
HP/Torque with insert/open: 109.5 HP/ 44 LB-FT; 111.6 HP / 44 LB-FT
DB at WOT with insert/open: +2/+10
DB at cruise with insert/open: +2/+10
Fit and finish: 10
The Word: LeoVince has deservedly earned a name in the high-end exhaust business. In addition to scoring well on the dyno and the scales, the GP Pro has the fit and finish of artwork. The pipe looks and sounds like it belongs on a MotoGP monster. The exhaust note is deep and raspy, but subdued with the insert in place. LeoVince also offers more traditional pipe designs in stainless steel, carbon fiber and titanium. But trust us, in person this bad dog is a true beauty.
Hotbodies Racing MGP Growler Carbon/Stainless Slip-on
Construction: stainless piping and end cap, carbon fiber muffler
Weight: 2.60 pounds
HP/Torque: 112 HP/ 44 LB-FT
DB at WOT: +17
DB at cruise: +16
Fit and finish: 9
The Word: Straight from the MotoGP paddock and onto a bike near you, the MGP Growler slip-on chocked up the title of the lightest cat-back slip-on and made solid power in the process. Being a shorty pipe means it’s on the loud side, but the byproduct is sweet, sweet racebike sound at WOT wrapped in a unique design that looks tiny next to the others.
The pocket-sized killer is crafted in Italy and at $299.95 it’s also damn affordable. For those looking to save a buck, increase performance and style and want a lot of bark to match the bite, the MGP is hard to beat.
Akrapovic Titanium/Carbon Slip-on
Construction: Titanium muffler and piping, carbon fiber end cap
Weight with insert/open: 3.96/ 3.70 pounds
HP/Torque with insert/open: 111 HP/ 44.3 LB-FT; 112.2 HP/ 44.5 LB-FT
DB at WOT with insert/open: +2/+4
DB at cruise with insert/open: +2/+3
Fit and finish: 10
The Word: Quality goes hand in hand with Akrapovic and this titanium and carbon fiber version came within one HP of the top spot despite breathing through the stock cat (the winning pipe ditched the factory cat). Of course Akro also sells an closed-course cat-delete should you want a few more ponies.
Fit and finish were top-rate and the deep, robust sound quality of the uncorked pipe is what we’ve come to expect from them. The dB insert did an admirable job of killing sound without the power and the edged muffler design is as classic as it is modern.