1993 arctic cat thundercat

"Lead, follow or get out of the way," is how Arctco president Chris Twomey explains Arctic Cat's 900cc Thundercat. If you are a Thundercat rider this season, trust us when we say that you won't be following or asked to get out of the way.

In our brief, but telling, test ride of the new Cat triple, we rate it as the most awesome snowmobile we've ever ridden. Not the most awesome Cat. The most awesome snowmobile. Period.

Not only is the new Thundercat the biggest displacement snowmobile in the business, but based on educated guesses from aftermarket engine builders and dyno experts we've heard that this engine could be delivering well over 150 horsepower in stock "mild" form. Cat spokesmen smile broadly when they note that the addition of 44mm carburetors and some internal porting changes gives the Thundercat triple the opportunity to "…have lots of horsepower."

Awesome is a frequently overused word in performance circles. It applies here. Consider that at its initial clutch engagement speed of about 3,000 rpm, the Thundercat triple is said to produce more torque than the Prowler's 440cc twin does at full throttle. Cat technicians state matter-of-factly that the new Suzuki-built three cylinder also produces more horsepower at idle than a number of other snowmobile engines.

Last spring we test rode the Thundercat in West Yellowstone, Montana. At Yellowstone there is an unplowed airstrip that has become the area's official (but unsanctioned) place for sled-to-sled challenges. It was also where we challenged the Thundercat to a run against one of last year's top performers, the 700cc Wildcat. No contest. Even when we gave the Wildcat the holeshot, the Thundercat could readily catch up and blast by. During other runs, the Thundercat rider would catch the Wildcat, maintain the same speed, go to wide open throttle, and accelerate away.

Simply stated, the 120-ish horsepower Wildcat, which was the performance champ in our "Battle of Old Forge" challenge of last year's premium performance sleds, was no contest for the Thundercat. On a Thundercat, the airstrip at Yellowstone got short in a hurry!

Unlike some performance sleds of the past, the Thundercat is uniquely docile. The low engagement speed means that you can readily trail this sled. In order to get horsepower out of some peaky performance engines, the engagement clutching had to be set at 5,000 rpm or higher in Yellowstone-like elevations. That wasn't the case with the Thundercat. It's almost like driving a big-engined 454 cubic inch American V-8 with a low revving torque curve. A touch of the throttle and you are motoring. A full handful and you are ballistic.

The only drawbacks we could see to this much power were: if you let off the throttle all at once, weight immediately transfers forward to the skis and unloads the track- and traction; to get this much power to the snow requires traction capabilities that may not exist.

The first "problem" has an easy solution. Back off the throttle in stages. From full throttle, back down to half and then to quarter or all the way. This will minimize weight transfer.

Secondly, Cat technicians acknowledge that "traction is the name of the game" for this machine. Increased traction could be achieved by installing a Mountain Cat rear suspension and extended track set-up on this sled. While the current Thundercat only comes with the 121-inch full block Kevlar track, you might be able to fit the longer length track and suspension. We fully expect a Mountain Cat version to appear no later than next year. After all, mountain riders are going to get totally excited about this sled/engine combination. Where mountain elevations rob horsepower, bigger is definitely better.

In our limited testing, we noted that the Thundercat could easily "power spin" the track the entire length of a football field under full throttle on the sloppy snow conditions we encountered. Getting the track to hook up on ice and hardpacked snow will require some experimenting and, perhaps, a good working relationship with your Cat dealer. We expect that Cat will come up with some expert suggestions for stud patterns, etc.

This range of performance comes from what Cat admits is a mildly tuned version of the 900 triple. The crankcase reed, claims Cat, sends a fuller charge of fuel into the engine and is as effective as Rotax' rotary valve system in eliminating "blow back." Indeed, Bombardier uses reed induction on its own 774cc triple.

The reed induction block is fitted with rubber "booties" that could readily accommodate larger 44mm carbs. The reduction to 38mm Mikuni round slide carbs allows Cat to offer a terrific sensation of power, while still maintaining some semblance of economy. With its 11 gallon fuel tank and some consideration, we would expect that the Thundercat can stay out on the trail as long as any other touring sled.

Surprisingly, the Thundercat could be an exceptional touring machine and economical on fuel, if you can keep your throttle thumb under control when you hit a wide open lake or meadow. Riding at normal touring speeds would require relatively low rpm with the 900 and we figure decent fuel economy. It is very smooth from engagement speed to full throttle. Much of that smoothness comes from a gear driven counter balanced shaft mounted on the exhaust side of the motor.

Getting the new triple into the existing Wildcat chassis took a little extra engineering. Last year Cat engineers reworked the basic "wishbone" chassis by extending the front side panels and bulkhead a couple of inches. To get the 900cc triple and its three individual tuned exhausts to fit where the Wildcat's 700cc twin used to be required relocating the suspension mounts and A-arms.

The Arctic Wishbone Suspension III is a pragmatic revision of the Wildcat front end. Instead of vertical shock placement, the Thundercat has "lay down" shock position to make room for the tuned pipes. While the new power sled retains the same seven inches of front suspension travel as the Wildcat's AWS II suspension, the action is a little different. It's not noticeable when switching from a Wildcat to the Thundercat. You still have a progressive rate coil spring mounted over a gas shock, and heavy duty sway bar.

Steering effort is increased a bit because you have added a third cylinder up front and are faced with what Cat technicians stated was about 40 pounds more weight than a Wildcat 700. But it didn't seem any less responsive than the base Wildcat.

At the rear is the Arctic FasTrack extra long travel suspension. Except for revised spring and shock rates, it is the same as the Wildcat suspension which was re-engineered last season. At that time Cat engineers smoothed out the slide rail profile, reducing track friction. For 1993 the Thundercat and Wildcat models use gas shocks in the rear suspension. Overall travel is 8.5 inches, the same as last year.

On our prototype test sled, the windshield and instrument pod were handlebar mounted. Cat has changed that since our late season preview ride. Now the windshield is integrated into the hood design. Seems that while Cat designers created the Prowler with a handlebar-mounted fairing, like the Yamaha Phazer; performance Cat riders preferred a hood-mounted windshield like that used on the EXT series.

Full instrumentation includes: tach, speedometer, trip meter, gas gauge, low oil warning light, and temperature light. Hand and thumb warmers, carbide ski runners, parking brake, and aero-style halogen headlamp are also standard equipment.

There is no electric start option. Cat technicians state that the 900cc triple "…starts very easy." We found that to be true, but we were always starting a warm engine. The story with any motor may be different on a bitterly cold and blowing winter's morning.

As we have noted, the Thundercat is awesome. Going from an EXT 550 to a Wildcat 700 is a performance jump. But the performance gap between that same Wildcat to the Thundercat is even more pronounced. It is amazing that the same basic Arctic/Comet drive and Arctic driven clutch system can control the power. Cat technicians assure us that all Cat performance clutches are the same, except for weights and springs. The distance between the primary and the secondary clutches, though, is about an inch greater on the Thundercat, which requires a longer drive belt.

When Cat engineering upgraded last year's Wildcat to a wider drive chain, thicker sprockets, and beefier jackshaft, it was done specifically with the new 900cc three banger in mind.

As has been revealed already, the new T-Cat chassis is also the basis for the new "hot rod" EXT 440ZR and EXT 580ZR stock racers. We have to give Cat's engineering crew a tip of the knit cap in the planning for the future department. They do seem to have a definite program in mind. That bodes well for us American snowmobilers who will see new Cat technology trickling down from season to season. Some of the technology will be much more than a trickle. Watch the race tracks over the next few years for hints of what Cat designers plan for us to be riding into the new century.

Yes, Cat engineers planned ahead. But, so far, that planning doesn't include an electronic fuel injected version. Cat spokesmen noted that they hadn't heard a demand for it. Early last spring they had heard of a demand for the Thundercat where some consumers had visited Cat dealerships and were putting down thousands of bucks on the new sled- sight unseen.

Well, we've seen the sled. We've ridden it. We've formed impressions. It's awesome. If you own this Cat this winter, you'll be able to go anywhere you want. You will be the leader. Everyone else will have to follow or get out of the way.