Before the 1997 model year, the Ski-Doo faithful had had to make do with the well-proven 670 twin if they wished to stay in the 700 class. While it was lighter than the triples and offered plenty of torque in the low-and mid-range, the twin motor just didn't have the top end snort to keepup with the other muscle sleds down the stretch or across the lake. To relievethe situation, Ski-Doo unveiled the 699cc Rotax Triple in its Mach 1 last season, to a reasonably solid response.
We had the opportunity to run a 1997 Mach 1 in the American Snowmobiler Shoot Out last December and we were fairly impressed with the freshman motor. While Polaris' Ultra SPX took the top speed at the quarter mile, the rest of the 700 class honors went to the Mach 1. At the eighth, the Mach was both quicker and faster than the competition, posting 84.27 mph in 7.72seconds in Box Stock form. The next closest sled was over 3.5 mph slower and nearly a half second behind. Our Dealer Prep runs offered little improvementover the Box Stock, but it was still quicker to the eighth- and the quarter-mile marks than the competition.
On last year's Shoot Out dyno runs, we found a class-leading 139.2 hp at 8250 rpm on the Mach 1. This year our dyno testers ran a '98 Mach 1 with the central outlet pipes and found significantly more power at a lower rpm,and they didn't have to work too hard to find it. "We initially started out with the stock settings, only changing the jets for the conditions,"commented Dyno Port's Rich Daly. "After a couple runs, the pipes heatedup and we added nearly three horses to get an even 142 horsepower from theMach 1 at a surprisingly low 8000 rpm."
A look at the dyno chart tells us that consumers will have no problem getting their new Ski-Doo clutched to the power. A generous 300 rpm band delivers power over the 140 hp mark. The Mach 1 will be stretching armswith almost 90 foot pounds of torque as low as 6400 rpm.
But speed and power aren't the only things that impressed our dyno guys."It's unreal how quiet this sled is," said Daly. "It's like we're running an electric motor, not a two-stroke snowmobile." Thecredit for this is due to the central outlet pipes found on the new CK3 chassis sleds.
Finding additional power in the Mach 1 shouldn't be too difficult Daly speculated. "There's definitely room for improvement with this setup.It hits its power at a pretty low rpm, and that usually indicates that tuners will be able to find a few horses by raising the engine speed in conjunctionwith a new set of end outlet pipes. There's also a possibility for improving the airflow on this sled to give it more power. All in all, I'd guess wewill see around an eight to 10 hp gain from the aftermarket."
With a stronger stock setup and the possibility for additional power from the tuners, Ski-Doo will definitely have a contender in the 700, three cylinder, three pipe class.
Again our thanks to Mike Ingalls of Ingalls Performance in Phoenix, NY for loaning us a test sled.
American Snowmobiler is pleased to work with DYNOPORT in passing along the dyno tests of key snowmobile models. DYNOPORT is an independent performanceand dyno facility located in Union Springs, New York. American Snowmobilerand DYNOPORT make every effort to assure the accuracy of articles and technical information; DYNOPORT assumes no responsibilities for damages due to errors,omissions or applications of any information. DYNOPORT, 1896 Townline Road,Union Springs, NY 13160 · 315-258-9371.
1998 Ski-Doo Mach 1
Air Density: 95.3
| RPM | CBT | CBHP | BSFC | FUEL | H2O |
| 6400 | 87.5 | 106.6 | .684 | 70.8 | 84.5 |
| 6500 | 88.2 | 109.2 | .680 | 72.0 | 85.0 |
| 6600 | 88.8 | 111.6 | .660 | 71.5 | 85.5 |
| 6700 | 88.9 | 113.4 | .646 | 71.1 | 86.5 |
| 6800 | 89.4 | 115.7 | .642 | 72.1 | 87.0 |
| 6900 | 90.4 | 118.8 | .669 | 77.1 | 87.0 |
| 7000 | 91.9 | 122.5 | .652 | 77.5 | 87.5 |
| 7100 | 91.9 | 124.2 | .664 | 79.9 | 88.0 |
| 7200 | 91.6 | 125.7 | .721 | 87.9 | 88.5 |
| 7300 | 91.3 | 126.9 | .672 | 82.8 | 89.0 |
| 7400 | 90.8 | 127.9 | .638 | 79.1 | 89.5 |
| 7500 | 90.9 | 129.7 | .617 | 77.7 | 89.5 |
| 7600 | 91.5 | 132.4 | .658 | 84.5 | 90.5 |
| 7700 | 92.7 | 135.9 | .660 | 86.7 | 90.5 |
| 7800 | 93.1 | 138.3 | .657 | 88.1 | 91.0 |
| 7900 | 93.6 | 140.8 | .617 | 84.3 | 91.0 |
| 8000 | 93.2 | 142.0 | .603 | 83.1 | 91.5 |
| 8100 | 91.5 | 141.2 | .613 | 84.0 | 91.5 |
| 8200 | 87.3 | 136.2 | .692 | 91.5 | 92.0 |
| 8285 | 80.2 | 126.6 | .703 | 86.3 | 92.0 |
RPM: Engine crankshaft speed.
CBT: Corrected Brake Torque.
CBHP: Corrected Brake Horsepower.
BSFC: Brake Specific Fuel Consumption.
FUEL: Actual fuel flow pounds per hour.
H2O: Water temperature in degrees F.