Axys crank into a Pro

[SnowJunkie82]

Anyone on here putting the new Axys 800 crank into a 13/14/15 Liberty motor? Sounds like it is a direct swap. Way less rotating mass especially if you used a light weight primary.

 

[ippielb]

I have a light weight crank shaft on my sled. It was done by speedwerx, they machined off the webs and true and welded it with titanium rods.

Can be done at a machine shop and get it balanced afterwards. It's unreal the amount of material they took off my crank.

http://www.speedwerxstore.com/index.php?l=product_detail&p=2171

 

[SnowJunkie82]

What kind of performance changes did you see? Better response? Higher revs? What about the torque curve on the motor how much did it change?

 

[ABMax24]

What kind of performance changes did you see? Better response? Higher revs? What about the torque curve on the motor how much did it change?

Inertial crankshaft weight won't change anything but throttle response and vibration, higher revs/torque curves will come mostly from changes in porting.

 

[ippielb]

Haven't gotten to run it yet! From just the weight difference in holding a stock crank in comparison to the machined one its a seat of your pants 5 pound difference. And that 5 pounds(round it up from speedwerx 5 i dunno why lol) is rotating mass. The throttle response and low end is what I was going for. The way my crank was machined it put flat ends on the webs so as it rotates it almost seems as if it will force air up into the cylinders as it spins. That is speculation of course. All in all, some Gus spend $1,500 on a carbon fibre hood to lose 5 pounds, I spend $1,800 on a brand new light weight crank with new bearings and lost 5 pounds of rotating mass.

another thing with lighter crank it should idle smoother with less weight to turn, and when you let off throttle it should lose rpm faster less mass to keep it spinning. Pros and cons. I like lighter though.

 

[SnowJunkie82]

If this were put in a stock sled would the fuel mapping need to be changed or could the stock ecu support it?

 

[ippielb]

If this were put in a stock sled would the fuel mapping need to be changed or could the stock ecu support it?

Shouldn't change anything on the fueling, you aren't adding more air or restricting airflow. I am no expert on this though this is new to me as well on my built motor. I am hoping to bring out my dyno for the first time this fall to see what kind of numbers I can get on my d&d big bore 800 with rktek head with turbo domes, speedwerx light crank, and aerocharger 53. I wanted to gets much low end snap as I could with the turbo to make a fun boondocking sled. 13.5" narrow track will be a nimble little sled.

 

[SnowJunkie82]

Shouldn't change anything on the furling, you aren't adding more air or restricting airflow. I am no expert on this though this is new to me as well on my built motor. I am hoping to bring out my dyno for the first time this fall to see what kind of numbers I can get on my d&d big bore 800 with rktek head with turbo domes, speedwerx light crank, and aerocharger 53. I wanted to gets much low end snap as I could with the turbo to make a fun boondocking sled. 13.5" narrow track will be a nimble little sled.

Should be a fun sled and a great build! Let us know how it works on the snow.

 

[ippielb]

Should be a fun sled and a great build! Let us know how it works on the snow.

Haha only problem is the sled is 10 years old. Dropped enough money into it I could've bought a new sled.

Anyways back to your thread. I would highly suggest to try and get someone to machine the webs/counterweights on your crank. Before dropping the money on a new crank all together to have it "might" work.

 

[SnowJunkie82]

I priced a new Axys rotating assembly and it comes in at $1985.00 from Cervus in Pincher Creek. I'm building a new Pro with Boondocker turbo setup that has the oiling on the turbo tied into the oiler on the motor. So the motor will need to be pulled to hook this up (or the lower inspection plate removed). So a tear down on the motor wouldn't be a huge stretch.
Just trying to decide if the gains are worth the hassle.

 

[ippielb]

Might be cheaper to find a good used crank and machine it and get new bearings.

 

[takethebounce]

Pretty sure Burandt and Co were running this combo either last season or had it set up for this season. Maybe fire them off a message for more details.

 

[SnowJunkie82]

Pretty sure Burandt and Co were running this combo either last season or had it set up for this season. Maybe fire them off a message for more details.

I picked his brain for about 30 min yesterday and he was the one that got me thinking about it. He's trying it on two of his machines this year. Defiantly one on his carbon fibre sled and maybe one on a stock machine. He had the Polaris factory race team assemble the motors for him. Must be nice! The other thing he said that made a difference in engine response was a carbon fibre primary clutch cover with titanium bolts. This year he sent his whole primary to Patrich's to have it shaved and balanced. Figures this will lose a 1lb between this, the cover and the bolts.
It all sounds pretty cool, but a lot of time and money!

 

[takethebounce]

Yeah it's just money. No end to what you can do with it.


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[snopro]

Aaron you probably have more money than Burandt. Just do it! Lol.

 

[SnowJunkie82]

Lol! I really hope for his sake that isnt true.

 

[snopro]

He's a sponsored rider. I bet he isn't as well off as many think. I bet none of them are.

 

[schiermnultra]

I'm sitting over here looking for sponsorship.