dyno test arctic jaguar z1

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It's not brand new for 2008, but we thought many of you would be interested to see just how the Arctic Cat 4-stroker would perform on Dynoport's official pull. We had our man Rich Daly take a day to give this thing a rip and here's what he found.

Torque down low
On the bottom end, this Suzuki-built engine has plenty of torque, and while it doesn't sound like a tractor, it sure pulls like one! We've reported in side-by-side tests that the Z1 is faster than its lighter, slightly weaker brother the F6, and our dyno tests reflect that too.

The Z1 recorded a full 121.8 horsepower at a smooth 8,500 rpm. That's only a few more horsepower than the Dynoport tested 118.2 horsepower from the 600cc powerplant in Cat's F6.

So why does the Jaguar dust the F6 after about 500 feet? First, the Z1's torque is big and the powerband is wide. It will hold almost 80 foot-pounds of torque throughout the band with just a little fall-off on the top end. However, if you look at power-to-weight, the lighter F6 should be the victor.

The Jaguar simply has longer legs and continues to wind out. Cat rep Kale Wainer confirms that what we found in our testing is similar to the factory conclusions. "On our factory dynos, the Jag has more horsepower and also wins in drag races on straight ice, the Z1 always wins," Wainer said. "Weight isn't always a big deal."

Also, because the Z1 does not have an 87 octane requirement, we are guessing that using the higher octane (we often ran 91-93 in this sled) helps the 4-stroke on top end, giving it an edge over the F6. For '08 the Z1 comes with iridium sparkplugs for improved cold starting, and it also has some mapping changes for better drive-away. We experienced some plug fouling last year and these changes should solve that.

4-stroke vs. 4-stroke
So the natural engine to compare to the Jaguar's 1055cc big twin is Yamaha's 973cc triple-cylinder Genesis 120 that recently was dropped into Yamaha's Deltabox II chassis for the revamped Vector. We dynoed the Yamaha engine last year to have 120.4 horses at 8,400 rpm, and again this summer at 122.6 hp at 8,400 rpm, so these two engines are extremely close on power output. Torque is flat for the Yamaha too and hovers around, or just below, 80 ft.-lbs. through the band.

After seeing these numbers, it's going to come down to handling when these two face off on the trails, especially considering that their dry weights are within a couple pounds of each other, there's no real advantage, at least on paper. Our suggestion if you challenge someone on another brand's sled? Lay off the donuts that morning!

2008 Jag updates
There were several changes made on the Z1s for 2008. Some changes are the same as the F-sled and some are different. Listed below are some of the more important changes for the Z1.

• New Iridium sparkplugs (with special ring of porcelain on the bottom) for improved cold starting
• ECU mapping changes
• Airbox inserts have been removed. Self-tapping screws hold it together. The rubber flange is now a better fit to throttle bodies
• Drive clutch is now using line-bored covers for better strength, increased roller life
• Non-adjustable, standard mid-height windshield
• New sway bar mounting is 1.3 inches further out on each side. The bar is 13.5mm. There is a hardware change too for the different sized bars