UTV PROJECT WILD CAT Exhaust, suspension, tires and cooling
Last month we brought you the first shootout featuring the Arctic Cat Wildcat. We put this new contender in the sport UTV class up against the popular Polaris RZR XP 900 and the just-as-fast Can-Am Commander 1000. After weeks of torture testing, we found a few issues on the Wildcat that we could improve to make it competitive with the others. This month we are going to address these items on our Wildcat and let you know which products made the most improvements.
Sure the 951cc Wildcat is fast, but it’s still not as fast as the RZR XP 900 or the Commander 1000. The easiest way to get more power out of a stock machine is to let it breathe. To do this, we called on Ron Wood Racing. RWR has a long history of building super-fast V-twin Commander engines and is the first company to have a performance package ready for the Wildcat. The RWR kit we used is their complete, high-performance, reverse-megaphone, twin-pipe exhaust. This system is made entirely of 304 stainless steel that bolts in the stock location and sells for $895. To complement the free-flow exhaust system, we also improved the intake side by installing a K&N filter in the stock airbox for $70. To get the added fuel flow we need for this project, we hooked up a Dyno Jet Power Commander fuel controller ($370). Ron Wood Racing carriers all of these items, as well as a race intake ($271), high-compression pistons and more. If you have a Wildcat engine starving for attention, give Ron a call at (949) 645-0393, or
visit them online at www.rotax.net.
After replacing the stock exhaust with the Wood system, we compared the notes we had from testing the stocker on our track. In a 100-yard acceleration run with perfect traction and a slight incline, the Wood, K&N, and Dyno Jet setup completed the test in 12 seconds (versus 15 seconds with the stocker). That may not sound like much, but when you’re drag racing your buddies, a three-second difference will have them eating your dust. On the same run, the stock Wildcat reached an even 50 mph. The modified ’Cat was going 55 mph when it crossed the finish line, so the modified version would still be pulling away from the stocker well after a 100-yard run. According to our Trail Tech Voyager (www.trailtech.net) speedometer, the Wildcat now tops out at 75 mph. We were only able to get it to 73 mph in stock trim. That is now slightly faster than a stock RZR XP 900.
While this next improvement didn’t help produce power, it helped save it. We installed cooling vents in the rear-engine firewall to increase airflow to the radiators and the engine itself. The four, thin, aluminum vents bolt right to the stock plastic radiator cover panel behind the seats. You do have to route out sections of plastic that measure about two square feet. According to Wildcat Willy’s, their testing showed a 50-degree temperature drop in the radiator with the vents installed. Another product Wildcat Willy’s has for the Arctic Cat project is a bright-green powder-coated aluminum roof for $250. It keeps the sun and rain off the drivers and improves the looks as well. Wildcat Willy’s has a host of products we will test on the Wildcat in the near future, including a new clutch system ($299–$599) that will no doubt improve lap times even more. Contact Wildcat Willy’s at (435) 592-9469 or visit www.dandpperformance.net.
With a different product, we also eliminated some heat from affecting the performance of the left rear shock. That shock sits very close to the stock head pipe. Our tests show that this shock runs 20 degrees hotter than the one on the right side. So to reduce the heat in the area, we wrapped the head pipe with a high-temp, fiberglass header wrap. It instantly evened out the shock temperatures. This was needed with the stock system, and the Ron Wood exhaust. You can purchase the heat wrap by the roll from CV Powersports at (800) 448-1223. CV Powersports also sells the temperature strips we used for this test. View their products online at www.cv4.net.
Traction and tire durability also seem to be holding the Wildcat back some. The Duro tires tha come stock are decent, but not great. In only 100 miles of testing, we burnt off 50 percent of the tread and had two flats. Both flats were driver error, however; we saw the rocks that caused the flat tires and should have avoided them. Also, in 2WD, the rear end of the ’Cat lacks the traction to put all 951cc of power to the ground efficiently. It roosts and fishtails pretty aggressively. In 4WD, we are having trouble turning the Wildcat effectively around sharp corners. In stock trim, you can really feel the front tires pushing instead of biting and taking you through the turns.
To fix this, we have tried two different sets of tires. The first was STI’s Black Diamonds and the second is the GBC Dirt Commanders. The Black Diamonds definitely held up much better than the stockers. You could still see quite a bit of wear on the Black Diamond knobbies, but we could never get them to fail. In fact, we abused them heavily against the same rocks that punctured the Duros, and when we tried to see if we could get the stock wheels to fail, both came through with only minor wear.
The stock aluminum Arctic Cat wheels proved to be very strong, almost bulletproof. So instead of getting new wheels for this portion of the test, we installed a brand-new set of GBC Dirt Commanders on the stock dubs. To try to get the rear end to slide better (in four-wheel drive) and the front tires to grip as much as possible, we installed 26×9-14 sizing on all four corners at $135 apiece. The lighter, narrower rear tires might also help acceleration. We tried this concept on old RZRs and Rhinos and had good success.
The GBCs performed great. Forward and stopping traction was perfect. Even with the narrower 9-inch rear tires (stock is 11 inches), take-off traction was excellent. Cornering traction issues weren’t completely solved with the GBCs, but we could corner harder and faster around the entire test track. We ended up knocking off another two seconds from our fastest lap and were now within two seconds of the RZR XP 900’s fastest time. After a week of testing, the GBC Dirt Commanders are holding up extremely well, much better than the stockers. We will keep punishing them and report back. To find a GBC dealer or see other GBC tread patterns, check out www.gbc motorsports.com. You can also get these tires at any Discount Tire retailer.
Another way to get the Wildcat to turn better is with a shock setup. We have been working with Race Tech on handling improvements as well. The stock Walker Evans shocks already get the Wildcat through the rough stuff better than any other stock two-seat UTV on the planet. What Race Tech did was experiment by putting a single-rate spring out back instead of the stock dual-rate setup, so this way preload adjustments were more noticeable and easier to make. With the rear preload increased about 15mm, we can get the ’Cat to carve the corners better. We also had Race Tech revalve the compression damper stiff enough to where the softest setting is now like how the stiff setting was before. This didn’t affect the ride comfort at all; it still floats over the chop like a pillow. What it does is it gives us more room to tighten things up for aggressive driving or racing. Race Tech can do this to your stock Walker Evans shocks as well. Call them at (951) 279-6655 or visit www.racetech.com.
Where all of our hard work really paid off is around our entire six-mile test track. With the power improvements of the Wood engine hop-ups and traction enhancements of the GBC tires, we were able to shave six seconds off of our old lap time. Nine minutes, two seconds is now our fastest time around the six-mile track in the Wildcat. The RZR XP 900’s lap time is still faster at nine minutes flat, but we are gaining ground. Clutching is still the hiccup in getting the midrange on and off the throttle power and to the ground. We will work with EPI, Wildcat Willy’s, and other clutching companies to try to get the Arctic Cat engine working to its full potential and report back every step of the way.
We will now take items like the modified Walker Evans shocks, GBC tires, Ron Wood exhaust and Wildcat Willy’s cooling fins and bolt them on another machine and take it to the races. The unit we will be racing is custom outfitted by TurnKey UTV. The guys at TurnKey ( 883-1568, www.turnkeyutv.com) built a strong yet streamlined roll cage and added solid side panels where the doors used to be. Inside the cab, TurnKey added beard seats, seatbelts and window nets to keep within the rules of WORCS racing. Check out how the TurnKey Arctic Cat Wildcat performed against a sea of RZR XP 900s at the WORCS event in a future issue. Or, to see video footage of the race, log on to www.dirtwheelsmag.com now. q