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Two 600 engines?
We were kind of left scratching our heads again this year when yet another manufacturer announced it was going to have more than one 600 in its lineup. It seemed to us that Polaris' 600 H.O. carbureted model sold well enough last season to keep driving sales again this year. So why go through the effort of creating a second engine option in the same class?
AmSnow decided we needed to get this new Polaris 600 Cleanfire on the dyno and find out if there was sound performance-related reasoning behind this decision.
History lessonBefore we get to the cold hard numbers that Rich Daly at Dynoport pulled from this engine, we should look at past Polaris 600 engine dynos for a reference point. Last year we tested the Fusion 600 H.O. and found it to be a consistent 119 hp at 8,200 rpm. That was pretty darn close to the Polaris brochure, which stated it had 120 horses!
We had this machine in our test fleet last season and saw plenty of torque out of this little puppy once we dropped down a couple main jet sizes and tested her against her Fusion 900 predecessor. It was almost comical because the 600 would pull right alongside the 900 for the first 500 feet or so. That's why we were left wondering this spring just why Polaris needed another 600 when the H.O. was working so well.
We also dyno-tested the Polaris XC SP - the precursor of the Fusion 6 - a few years back, and that pulled just 115.8 hp at 7,900 rpm.
Let's go back even farther in sled history to see the gains that have been made. In 1998 Polaris' Indy 600 twin was scoring 109 hp at 7,700 rpm while the Indy 700 twin was netting 124.5 hp. These over-square engines were adequate at that time, but we now have pushed the envelope of the 600 twins to be on par with many engines in the 700 class.
Do we really need all that power?
The answerNo we don't "need" the power, but a lot of us want it!
In our dyno testing of the new 600 CFI motor we found 125.4 horses were cranking out of this little 2-stroker at 8,300 rpm. "This thing is a hot rod and holds power and torque well throughout the band," said our tester, Rich Daly. "After our preliminary testing and talking with other performance shops, this sled seems very receptive to the adding of a single pipe, and you will most likely be able to see significant power gains with only a little extra effort," he added.
If you look at the rpm meter, Polaris' CFI, which aims to be cleaner running AND more powerful, makes its power and torque at a little higher rev than the H.O. The CFI's max torque is 79.8 foot-pounds at 8,200 rpm and the H.O. pulls 77.4 ft.-lbs. at 7,900 rpm. The CFI snaps off high torque numbers in the 70 ft.-lbs. range after just 7,200 rpm. Max hp is made at 8,300 rpm on the CFI vs. 8,200 rpm on the H.O.
ImpressionsPossibly the strongest stock 600 we've seen since the days of the Ski-Doo Formula III 600 and other big triples back in the 1990s.
To be honest, we were not 100% surprised by our findings because after our initial pre-season test rides we were confident that we could feel the power difference between the TM38 carbureted version and the Cleanfire Injection unit. While it's only 5 hp, it's no Herculean leap from one sled to the other, but just that little extra is nice to have.
If you like to tinker, the standard carbed H.O. may still be the option for you, as it may be better suited for tuners. But if you want a bone stock 600 that has a true extra 5 horses, then opt for the CFI.
When compared to competitors 600s from last year, the Polaris 600 CFI holds the raw horsepower trophy, and at 485 lbs. dry, it may have one of the best power-to-weight ratios in this class as well.
With rollercoaster gas prices it will be interesting to see the fuel economy difference between the two Polaris 6's once they have some miles on the production models this year.
Will the 4-injector design of the 600 CFI with its auto calibration really make a difference in the long haul? With the admittedly poor fuel mileage we saw out of our Fusion 600, averaging just 8 mpg last season, let's hope so.
Polaris 600 IQ CFI
599cc twin 2-stroke
RPM Horsepower Torque (ft-lbs.)
6,800 83.4 64.4
6,900 87.1 66.3
7,000 90.3 67.8
7,100 93.2 68.9
7,200 97.2 70.9
7,300 101.2 72.8
7,400 105.9 75.1
7,500 110.2 77.2
7,600 113.7 78.6
7,700 117.3 78.6
7,800 118.4 79.7
7,900 119.2 79.3
8,000 120.5 79.2
8,100 122.4 79.4
8,200 124.5 79.8
8,300 125.4 79.3
8,400 124.7 78.0
8,460 123.8 76.8