With the late-year introduction of the 1995 Formula III, Ski-Doo outdid itself, literally. Horse-for-horse, the 598cc Formula III out-powers the 669cc Mach I by nearly five horses. When we dyno-tested the Formula III at the American Snowmobiler Shoot-Out last December, it recorded a maximum of 127.4 hp at 8250 rpm. When DYNOTECH put the Mach I on the blocks in Batavia, New York last season, its maximum horsepower of 122.5 peaked at 8000 rpm. Results may vary, depending upon conditions, but when a 600cc sled essentially
matches a 670 in raw power, imagine how it will face-off against the other 600s in its class.
We found out first hand at last year's Shoot-Out in Old Forge, New York. On the dyno, the Formula III beat the others by more than 20 ponies. The closest was Arctic Cat's ZR 580 EFI with 97.7 hp at 8250 rpm. The new ZRT 600 wasn't ready for the '95 Shoot-Out.
When pitted against the Yamaha Vmax 600, Polaris XCR 600 and Arctic Cat
580 EFI, the Ski-Doo posted the fastest stock time and was the only 600 to break 13 seconds. The ZR 580 was runner up at 13.216 seconds after dealer setup. While the stock F-III produced its best time and top speed of 98.85 mph before dealer setup, it burned down after it was wrenched on. This was the result of overzealous mechanics who gutted the airbox, but didn't foresee a notable drop in air temperature.
Besides breaking the 13-second elapsed time barrier and besting the second
fastest sled (the ZR 580) by 10 mph, we saw other indications that the F-III
is tops. It recorded the best 0-60 feet ET at 1.672 seconds and the best 0-330 feet ET at 4.363 seconds. In fact, its 60-foot split was nearly two-tenths of a second faster than the 774cc Ski-Doo Mach Z, which was crowned fastest
in the 800 class.
All things considered, we expect the 1996 Formula III to be even faster. Engine improvements include new nicasil-lined cylinders, a new cam profile on the pistons, new piston guiding, new rings, a redesigned Rotax Intake Booster (RIB), and new engine calibration. These enhancements are expected
to produce better fuel consumption and crisper response. Also, the Total
Range Adjustable (TRA) drive clutch received machined sheaves, while the
driven pulley got a windage plate. Both changes should improve power transfer
to the track.
Last, but not least, new pipe and carburetion calibrations, combined with a new fresh air intake system (the same as the Mach Z), will provide better fuel consumption and more efficient burning.
The folks at Valcourt aren't predicting a horsepower increase for the '96 F-III over the '95. Because this 600 is already the most powerful in its class, Bombardier engineers are spending their time polishing the gem they already have.
1995 SKI-DOO FORMULA III
Weight: 588 pounds
Data for 29.92 inches Hg, 60 F dry air
Test:100 rpm/sec Acceleration
Fuel Specific Gravity:.745
Vapor Pressure:.25
Barometer: 29.73
| RPM | CBT | CBHP | FUEL | AIR | A/F | BSFC | CAT |
| 7000 | 76.7 | 102.2 | 48.4 | 174.8 | 17.4 | .48 | 47 |
| 7250 | 77.8 | 107.4 | 56.8 | 180.0 | 15.2 | .53 | 47 |
| 7500 | 78.6 | 112.2 | 63.2 | 181.7 | 13.8 | .57 | 47 |
| 7750 | 79.1 | 116.7 | 69.0 | 183.2 | 12.8 | .60 | 47 |
| 8000 | 79.9 | 121.7 | 72.9 | 184.8 | 12.2 | .61 | 47 |
| 8250 | 81.1 | 127.4 | 71.8 | 192.5 | 12.9 | .57 | 47 |
| 8500 | 72.2 | 116.9 | 73.3 | 200.3 | 13.1 | .64 | 47 |
RPM: Engine crankshaft speed. CBT: Corrected Brake Torque.
CBHP: Corrected Brake Horsepower. FUEL: Actual fuel flow
pounds per hour.
AIR: Airflow cubic feet per minute A/F: Air/Fuel/ Ratio
BSFC: Brake Specific Fuel Consumption. CAT: Carb Air
Temperature.