KWS Motorsports' Big-Bore Suzuki GSX-R1143 | WILD FILE

Takin' it to the street with KWS Motorsports' Suzuki Gsx-R1143 Packs A 200-Horsepower Wallop!

Many of us dream about riding a fire-breathing, 200-horsepower Superbike on the street, but few of us have the scratch for a factory racer-much less the racing rsum required to get a call back from the Yoshimura race shop. Well, what if we told you there was a cheaper and easier way to have your own street-legal Superbike-a GSX-R1000 that kicks out an honest 200-plus bhp, only this one starts at the push of a button, purrs like a kitten on idle and runs all day long on pump gas? Dream on, right?

Or, dream of calling Kevin Hunt at KWS Motorsports in North Charleston, South Carolina (www.KWSmotor Hunt and his crew are well known in roadracing circles as one of the top-performing privateer teams in AMA Superbike racing, fielding riders Matt Lynn and John Haner in 2006. In fact, a few years back when AMA Superbike Champion Mat Mladin was complaining about privateer Superbikes outrunning his factory machine on the straights, it was the KWS entry (then ridden by Shawn Higbee) that he was whining about. In addition to his successful race team, Hunt also operates a thriving performance shop and would be happy to build you the ultimate daily rider-which is exactly what we asked him to do. Since the AMA rulebook is irrelevant on the street, Hunt went about this project differently than he would a racebike. Since reliability and streetability were his main goals, he bumped up displacement to 1143cc with big-bore cylinders and a stroker crank to produce a substantial power gain without aggressive tuning that would make the bike difficult to live with day-in and day-out. The other priority was maximum midrange grunt: Hunt says another 5 peak ponies would have been no problem with bigger valves and more aggressive cams, but with street riding in mind he maintained a midrange-heavy tune.

KWS starts by shipping the cylinder block to Millennium Technologies, which punches out the oversized, 76mm bores and re-plates the cylinders ($550; JE Pistons supplies the forged pistons ($700;, which weigh 6.7 grams less than the stock slugs in spite of being 3mm larger in diameter. KWS then specs a new crank with a 4mm-longer stroke ($1395), to achieve a final displacement of 1143cc. To withstand the increased piston speeds, the stock connecting rods are replaced with lighter (43 grams less each), stronger, forged Carrillo H-Beams ($1095; Under the motor is a custom oil pan ($449) with a pendulum-style oil pickup that swings back when the bike launches forward, thus preventing the pickup from starving-and the motor from grenading.

Bigger bores make for greater fuel-burning capacity, and to move even more fuel and air into and out of the combustion chambers, the stock heads are ported to full Pro specs ($1350). The stock Suzuki titanium valves are retained in this application, but Hunt replaces the springs with the stiffer pieces from an '06 GSX-R750 ($160) and also adds custom-ground Web cams ($740; www.web, a set of APE adjustable cam sprockets ($165; and an adjustable billet cam-chain tensioner ($65). Lastly, a Falicon billet basket helps the clutch cope with the added horsepower ($495;

Once Hunt wrapped up the heavy lifting inside the engine, he turned to tuning. On went a LeoVince Corsa titanium exhaust system ($2268; and not one but two Dynojet Power Commanders-one to fine-tune each bank of the GSX-R's two injectors per cylinder ($339.95 each; www.dyno While the Dynojet catalog was open, Hunt ordered an Ignition Module ($355) to allow full tuning of the ignition curve, a Wideband Commander ($529.95) that allows on-board, real-time monitoring of the air/fuel ratio via an exhaust-mounted sensor and retrievable data acquisition, plus a Quick Shifter ($278.82) that allows full-throttle, clutchless upshifts. Finally, Hunt fitted the new Power Commander Multi-Function Hub ($189.95), which allows two fuel maps to be stored and interchanged with the flip of a handlebar-mounted switch.

Built to the hilt and wired up like the space shuttle, you'd expect this Gixxer to perform-and it does. The dyno chart is a revelation: The big-bore stroker makes as much torque at 5000 rpm as the stocker does at its 9750-rpm peak, and it only goes upward from there. Torque crosses the 90 lb.-ft. mark at 6400 rpm, and 100 lb.-ft. is dispatched at just 7200 rpm on the way to the new peak figure of 105 lb.-ft. at 8800 rpm. The horsepower curve is no less impressive: 150 bhp comes online at 7600 rpm, 175 bhp is available before 9000 and at 10,500 the fuel tank hits you in the face with a bonafide 200 bhp and keeps building to a peak of 209 bhp at 11,900 rpm. That's pole-position power right there.

What good is a Superbike motor without a Superbike-spec chassis? Penske ( upgraded the suspension front and rear, fitting the fork with uprated 20mm valves and stiffer springs ($420) and replacing the stock shock with a two-way adjustable 8760-series damper ($795) working through Vortex adjustable link rods ($57.95; www.vortex The non-adjustable factory steering damper was binned in favor of a Pit Bull Rotary Steering Stabilizer ($424.95;, and the brakes were upgraded with an AP Racing variable-ratio radial front master cylinder ($595 from, along with hard brake lines ($159), wave rotors ($590 front, $150 rear) and HH pads ($92) from Galfer (

To complete the handling package, a set of Dymag Sport Carbon wheels ($2885 from was mounted. Pure eye candy, these rims consist of carbon-fiber outer hoops mated to color-matched magnesium spokes and hubs. Light? You bet-they save 6 lbs. compared to stock. To reduce rolling resistance, KWS replaced the wheel bearings with ceramic units from Worldwide Bearing ($400;; when you build Superbikes for a living, no advantage is overlooked. Lastly, the bodywork was cleaned up with a full complement of Hotbodies ( goodies including trick mirror blanks/LED turn signals ($39.95), windscreen ($69.95), undertail ($189.95) and rear hugger ($179.95).

Even with stock gearing, riding the KWS Superbike is an exercise in wheelie control. Wick the throttle up and so goes the front wheel-in second, third, even fourth gear. If the throttle is wide open at anything above 7500 rpm, you'll be watching the birds. KWS race team manager Chip Spalding summed it up: "There's no reason for a bike like this to exist. It's crazy-fast and the most incredible street machine I've ever ridden. I absolutely love it!"

KWS has built a few dozen 1143cc GSX-Rs dating back to '01 and finds this to be a very reliable package. While the bike will run just fine on 93-octane pump gas, Hunt recommends VP Racing's 98-octane MRX01 if you plan on racing or riding it hard at the track. The big-bore Gixxer ain't cheap, but it's not as spendy as the $350K factory Superbikes that are its performance equal. Deliver your late-model GSX-R1000 to KWS along with $24,500 in cold, hard cash, and they'll build you one exactly like this.

It's up to you what you spend the remaining $325,500 on. Might we suggest a pallet full of rear tires and a retainer for a good traffic lawyer?

Pin to Win
Is 200 Horsepower Still Not Enough? KWS Motorsports Can Give You 220 Bhp If You Don't Mind Pinning Your Block

As impressed as we were by Kevin Hunt's bored-and-stroked GSX-R1143, 209 horsepower is just the beginning of what this guy can do with a naturally aspirated GSX-R1000 motor. Want 220-plus bhp? No problem, after Hunt gets serious in the machine shop. Hunt found that 3mm is the maximum overbore possible with a stock GSX-R block before the cylinder thickness is reduced enough that instability threatens its integrity. By pinning the block, however, Hunt found that he could go reliably up to a 5mm overbore for 1204cc displacement.

The process entails filling spaces that normally function as water jackets with large aluminum pins that reinforce and brace the bored-out block. The reinforcing rods are positioned with two in front of the cylinder and one behind, and the pins are radial-cut to still allow some water flow and some semblance of cooling capacity. Once reinforced, the pinned block is reassembled with 78mm JE forged high-compression pistons, plus all the other mods detailed in the previous story, good for more than 220 hp and 120 lb.-ft. of torque. Expect to spend around $11,000 for such a motor, and don't expect to run pump gas, as the compression on these engines stands in the neighborhood of 15.0:1. But if you're street-racer serious about having the baddest naturally aspirated literbike in the land, Kevin Hunt is your man.