True ??

[Modman]

lightweight cranks run smoother and have better acceleration, so long as the material is removed from the porkchop and not things like the journals etc (less weight and same strength). No drawback here unless you are running a high output motor that needs to maintain the RPM when loading is increased, not so much with 2 stroke sleds, so again - no drawback. A lighter crank could mean higher RPM, and therefore more peak HP, ultimately would really need to see a dyno graph and the torque curve on this motor before I trusted any crackbook marketing information about it making more useable HP than the competition - HP is just fictious and calculated values - doesn't mean jack squat until you see the numbers behind the numbers and match it all up. That aside, Poo is comparing this to Cat and Doo 2014 data as much of the 2015 data is still under wraps. so if its real, congrats to Poo for bragging that your 2016 sled will make as much HP as the competitions 2 yr old sleds.....

 

[drew562]

With some porting the Doo etec is close to 160 hp
Without 146 - 149 pending machine.

Stock Doo is 163 hp claimed. Cat is 165 claimed

 

[pfi572]

Stock Doo is 163 hp claimed. Cat is 165 claimed

Agree but they don't make that.
CLAIMED

 

[Clode]

lightweight cranks run smoother and have better acceleration, so long as the material is removed from the porkchop and not things like the journals etc (less weight and same strength). No drawback here unless you are running a high output motor that needs to maintain the RPM when loading is increased, not so much with 2 stroke sleds, so again - no drawback. A lighter crank could mean higher RPM, and therefore more peak HP, ultimately would really need to see a dyno graph and the torque curve on this motor before I trusted any crackbook marketing information about it making more useable HP than the competition - HP is just fictious and calculated values - doesn't mean jack squat until you see the numbers behind the numbers and match it all up. That aside, Poo is comparing this to Cat and Doo 2014 data as much of the 2015 data is still under wraps. so if its real, congrats to Poo for bragging that your 2016 sled will make as much HP as the competitions 2 yr old sleds.....

piston speed is more of an RPM limitation than crank weight

 

[maxwell]

It's a cute try I guess. Watch the other mfgs do nothing to beat it for about 45 seconds

 

[LennyR]

It's a cute try I guess. Watch the other mfgs do nothing to beat it for about 45 seconds

Does it sound kinda gimmicky to you. ? Lol

 

[CUSO]

I am sure there is something on the shelf for the other 2 brands and will get pulled off when needed.. Why put all the marbles in one basket and play catch up?
?

 

[ippielb]

Light weight cranks work awesome! If you do it right! Speedwerx started doing it to cats 700 lay down engines back in 04/05 for the 800 open mod sno-cross sleds. It worked so good for so many years that cat decided in 10 it would have the new 10HO come stock with the lightweight mod. So as long as Polaris does their testing and engineering right, there is no downfall. You don't hear of many cat HO's having bottom end problems.

My 700 big bore has te speedwerx lightened crank shaft. I'm hoping its a good improvement! When I fire it up this year.

 

[BRP QSC]

Be great if it is true. Polaris faithful deserve a decent, powerful engine.

I agree but be afraid of the 2.5lbs lighter crankshaft.... Cause Polaris hasn't had any engine problems right. Think about it... cold start 8000 rpm's and oops its bent. Not saying that would ever happen... just saying

 

[neilsleder]

I agree but be afraid of the 2.5lbs lighter crankshaft.... Cause Polaris hasn't had any engine problems right. Think about it... cold start 8000 rpm's and oops its bent. Not saying that would ever happen... just saying

Will never happen because everyone always let there sled warm up properly!


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[sledneck_03]

Light weight cranks work awesome! If you do it right! Speedwerx started doing it to cats 700 lay down engines back in 04/05 for the 800 open mod sno-cross sleds. It worked so good for so many years that cat decided in 10 it would have the new 10HO come stock with the lightweight mod. So as long as Polaris does their testing and engineering right, there is no downfall. You don't hear of many cat HO's having bottom end problems.

the cranks been in the race sleds for a year, this will be two as well as all the high miler short tracks out east will put a couple thousand on it this year as well.

 

[sledneck_03]

The glue idea worked awesome last time! Can't wait to see how well a "lighter" crankshaft works! After all, that is an optional part right?

that was kind of a funny joke in 2013, the glue was just fine in 2014

 

[neilsleder]

What do you think the crank clamp is going to look like?


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[maxwell]

What do you think the crank clamp is going to look like?


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Have to ask the aftermarket they will have a solution long before Polaris steals it

 

[Modman]

piston speed is more of an RPM limitation than crank weight

I hear ya , but didn't know anything else about the HO motor so was thinking if the other parameters (stroke etc) remain the same, maybe allowing them to spin the crank a little faster and gain a couple hundred RPM along with peak torque? The dyno values that I have for 105 ft/lbs of torque at 8100 is 162 HP, but bump that up only 200 rpm to 8300 and you now have 166 HP, this is where they can get an easy gain on the pre-production sleds for "peak power" advertising, but they will all be clutched for 8000 coming out of the factory. Could be a really peaky motor and come on in the last 1000 rpm. Could be 1 of 100 things. I could totally be wrong and the power increase has nothing to do with RPM, maybe more compression? or maybe the 3 stage PV's keep the torque longer in the powerband, maybe they pulled the numbers from 7400 RPM and then the motor falls on its face LOL? maybe their BSFC values are crazy low and not realistic for everyday riding (some other manufacturers have maybe done this in the past.....) but gave them some great marketing results before it melted in the dyno room?

RPM 8100	161.9383
8200	163.9375
8300	165.9368
8400	167.936
8500	169.9353
8600	171.9345

 

[Clode]

I hear ya , but didn't know anything else about the HO motor so was thinking if the other parameters (stroke etc) remain the same, maybe allowing them to spin the crank a little faster and gain a couple hundred RPM along with peak torque? The dyno values that I have for 105 ft/lbs of torque at 8100 is 162 HP, but bump that up only 200 rpm to 8300 and you now have 166 HP, this is where they can get an easy gain on the pre-production sleds for "peak power" advertising, but they will all be clutched for 8000 coming out of the factory. Could be a really peaky motor and come on in the last 1000 rpm. Could be 1 of 100 things. I could totally be wrong and the power increase has nothing to do with RPM, maybe more compression? or maybe the 3 stage PV's keep the torque longer in the powerband, maybe they pulled the numbers from 7400 RPM and then the motor falls on its face LOL? maybe their BSFC values are crazy low and not realistic for everyday riding (some other manufacturers have maybe done this in the past.....) but gave them some great marketing results before it melted in the dyno room?

RPM 8100	161.9383
8200	163.9375
8300	165.9368
8400	167.936
8500	169.9353
8600	171.9345

I am going to guess they ran it very lean, I am sure the real world numbers will be slightly lower, but who cares if the thing is tough and stays together.....more power is only a snail intall away