PROJECT UTV: Sparks Racing RZR XP 1110
Even with high-performance UTVs hitting 1000cc and topping 110 horsepower in stock trim, some customers are still searching for more power. Primarily it’s guys wanting the fastest machine at the track or the quickest in the dunes. Well, one motor builder that has been developing high-horsepower engines for ATVs since the beginning, Sparks Racing, now has the RZR figured out. While the Bakersfield, California, shop still builds plenty of ATV engines, including Honda TRX450s for pro riders David Haagsma and Beau Baron, the company has developed a complete line of Polaris RZR 570, 900 and XP 1000 engine packages. To test their top-of-the-line 1110cc RZR engine, we met them at the Pismo Dunes and had a day of fun.
To add the extra 110cc, Sparks didn’t just bore out the stock cylinder and stuff bigger pistons in. To do it correctly, they cast a brand-new, wider, closed-deck cylinder to accept larger, 98mm, 13:1, custom-made-to-Sparks-Racing-spec’d CP pistons. Although the stroke remains stock, new offset Carrillo rods were slipped on the stock crankshaft to get the pistons to move perfectly straight up and down. The cylinder kit sells for $2299.95. On this car, Sparks did some extra messaging on the head by replacing the valve springs, both cams, seats and guides, plus increasing the exhaust valve size 3.3mm, matching them closer to the intakes. Both the intake and exhaust ports were polished as well, bringing the head work price tag up to $1650.
No amount of motor work would be worth the extra expense unless you add fuel, get more air in & out and, in the case of a machine with a CVT transmission, tune the clutch. For this build the guys at Sparks Racing did all three. First, for added airflow, Sparks came up with their own $279 intake design that completely deletes the stock airbox and puts a new K&N filter right onto the stock plenum. This is that hollow box that’s basically between the exhaust and the throttle bodies. For fuel, tuning is done with a $400 Dynatek EFI controller. The fuel levels and ignition mapping can all be manipulated here or be set to self-tune if needed. Sparks loads exactly what mapping they think your specific application needs depending on modifications, riding terrain, altitude, etc. Out back, the $995.95 exhaust system is built with two stainless steel head pipes attached to a pair of aluminum canister mufflers. You can get the mufflers in raw or a variety of powdercoated matching colors.
For the CVT, Sparks has come up with an entire clutch kit that is specific for each engine package. The $325 kit includes new adjustable arms and spring for the main sheave and a spring and helix for the secondary. Also included is a stronger secondary clutch damper. It’s one of those parts that breaks easily and is worth replacing, even on stock machines. That part alone is $35.
Sparks’ test RZR had a few more items installed on it to finish it off. Some are items they sell in-house, others are not. The list of parts you can get direct through Sparks Racing includes a complete Fox Shox package. These are 3-inch-bodied shocks with stock travel numbers but include more oil, bigger shafts and rebound adjustments. Of course, high- and low-speed compression as well as preload adjustments can be made. The set of four shocks sells for $3995. This suspension setup was developed with the help of Cognito Motorsports. The company also supplied adjustable sway bar links that not only secure the stock sway bar better than the stock fasteners, they make it slightly adjustable. The pair of links cost $189.
Out on the corners, the four wheels built by Method are also available at Sparks. They cost $193 each and come with a 4+4 or 5+5 offset. Wrapped around the Method wheels for our day in the dunes were four lightweight Sand Tires Unlimited Sand Blasters. For now, the only UTV Sparks is developing and selling products for is the Polaris RZR line. The rest of the car was outfitted with a TMW cage, doors and roof. The stock plastic was covered by a custom wrap from Finish Line Signs right in Bakersfield, California.
When we turned the key and started the modified RZR, we were pleasantly surprised the machine was not overly loud. The twin Sparks mufflers do a good job sending a racy tone rocketing out the back instead of spewing an annoying scream. In fact, we think it’s much quieter than a single uncorked muffler on a sport quad engine. The sound does feel fast and sporty, building revs quickly and dropping off just as fast when you chop the throttle pedal. For comparison, a stock XP 1000 feels a little lazy when cruising around the dunes. Its 1500 pounds in soft sand is not exactly tail-happy. Driving the Sparks RZR was different. The motor was peppy, squirting the machine forward with every tap of the throttle. It felt more like driving on tacky dirt than in deep sand.
Drop the pedal to the metal (or the plastic pedal to the plastic floorboard) and the Sparks RZR came to life. It was peppy and strong, putting you back into the bolstered stock seat. There is zero lag, and the engine feels crisp and ultra responsive. We could dart from dune to dune like a jack rabbit and climb any hill, even when stopped at the bottom before take-off. The power was super impressive driving around solo, but what was more impressive was drag racing against a stocker. Our stocker also had paddle tires, and it was no contest between the two. Off the very bottom, the 1110cc Sparks RZR launched into the lead. And consistently, it would pull another full car length ahead with every 10 mph we added to the speedo.
From the clutch tuning to perfect power output, we were surprised at how well this machine worked. Yes, we know Sparks does good work, but it’s been a while since we have seen anyone build a CVT-equipped motor that is really impressive. We could feel a solid 20-horsepower gain that was completely usable and, according to the work Sparks Racing put into the package, is reliable. If you are looking for that kind of experience put into your high-performance sport ATV or Polars RZR engine, give Sparks Racing a call at (661) 872-4343 or visit www.sparksracing.com.