What is everyone finding the new engine likes to be at for rpm?
best rpm?
- Thread starter 2007dragonman
- Start date
Is this dyno at sea level? Doesn't peak power come at lower rpm as you get higher in elevation? I'm forgetting how this works. Steve at MDS clutching explained it to me last year. It's the reason that some guys swore by 8250 on the Pro, and some were adamant about 7850.
FWIW -
Testing 2 Axys this past weekend 9,390' elevation both 163 2.6 with the QD.\ both 210 miles- both ES. Have ran with eachother all along since new- so tried a few things.......
One stock everything/ didn't change a thing ....
2nd sled (mine) running belly buster weights, yellow Team spring, TKI belt drive 2.26 gearing, & 8 tooth drive out of a last years Pro.Stock Secondary other than the D washer in both clutches / Primary balanced.
Same hill- several good pulls-- bottomless snow, trial runs after each other and the stocker was about 1-1/2 sled behind constantly even switching riders.
Stock RPM 8150 /8200 38 MPH track speed, 100% throttle
2nd sled 8350/ 8380 RPM 45 MPH track speed, 100% throttle
Both have the PIDD and we were in the clutch mode recording runs./ and final gearing is the same on both sleds.
So dunno what SLP and other say the peak RPM is supposed to be at stock motor, but is was sure evident that the minumal work on the second sled, sure was very noticable.
Going to try 2.33 gearing this weekend ( mine) and see if there is a gain/loss...vs the readings and against the stock Axys.
Like to know what Peak RPM is supposed to be at elevation- dunno know if I am falling off or right at it.. but sure runs way better.. 15.8 hours on the motors
S/C
Testing 2 Axys this past weekend 9,390' elevation both 163 2.6 with the QD.\ both 210 miles- both ES. Have ran with eachother all along since new- so tried a few things.......
One stock everything/ didn't change a thing ....
2nd sled (mine) running belly buster weights, yellow Team spring, TKI belt drive 2.26 gearing, & 8 tooth drive out of a last years Pro.Stock Secondary other than the D washer in both clutches / Primary balanced.
Same hill- several good pulls-- bottomless snow, trial runs after each other and the stocker was about 1-1/2 sled behind constantly even switching riders.
Stock RPM 8150 /8200 38 MPH track speed, 100% throttle
2nd sled 8350/ 8380 RPM 45 MPH track speed, 100% throttle
Both have the PIDD and we were in the clutch mode recording runs./ and final gearing is the same on both sleds.
So dunno what SLP and other say the peak RPM is supposed to be at stock motor, but is was sure evident that the minumal work on the second sled, sure was very noticable.
Going to try 2.33 gearing this weekend ( mine) and see if there is a gain/loss...vs the readings and against the stock Axys.
Like to know what Peak RPM is supposed to be at elevation- dunno know if I am falling off or right at it.. but sure runs way better.. 15.8 hours on the motors
S/C
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RMK-King
Super-Moderator
How do you like the team yellow spring, engagement isn't to harsh making it trench taking off? 64G Bellybusters?
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The yellow gives only 400 more RPM initally, same final rate but put's you closer to the 1st stage of the power valves- and carries the mid range pull of the BB weights and no trenching at all - gentle as the stocker-on engagement.
Went that way cause stock spec's calls for 64's @ 6,000 to 8,000 and we ride well beyond that. and always liked the mid pull that the BB weight have always provided- the stock weights are heaver on the tip.. I took BB's 64's and cut them down to 62.7 grm
Have some stock polaris 62's for tip weight to try, & have 63.3's and 61.8 ready to run in the BB weights.
Obtaining the values of where to clutch this for max RPM ( stock) and touque values is tough cause it is not constant from the graphs on websights from aftermarket companies pushing their products... but the changes that were made... were aparant on the hill- for us anyway
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M
minus40
Well-known member
There is a new write up on DTR with a breakin of an SKS. Some good info on pipe heat and rpm.
IMO clutch to the peak hp, if rpm falls off a bit for some reason then your still in peak torque area to pull you through.
My flatland 800HO runs well at 82-8250. For those that hold WOT for long periods I would experiment with 83-8500 like Sage Crusher is doing.
IMO clutch to the peak hp, if rpm falls off a bit for some reason then your still in peak torque area to pull you through.
My flatland 800HO runs well at 82-8250. For those that hold WOT for long periods I would experiment with 83-8500 like Sage Crusher is doing.
He also went to a 8 tooth driver for less resistance and a shallower track angle approach, but I bet that he will really like that 2.33 gearing!
you should post some pictures of the 8 tooth drivers installed as far as tunnel clearance and track angle approach. Did you by chance put an angle gauge on it, is it really obvious how much more the driver sticks out?
Thanks
Justin
The reason(old school I guess)reducing the angle of the track coming off the drivers,rolling resistance, and spearing the track has been lessened also
All I can say for right now is, the motor likes to spin and with not a for sure a 100% correct rpm/ torque at elevation spec ( still digging for that one)- doing what is working-and getting very respectful results... I don't want to have it diggin to china- but it could be better suited for tree bangin'( on/of throttle) with the next step of gearing-
For boondocking group- but I think we have that one pretty much addressed with this driver swap/ clutching / and gearing.
Sled is lovin 8300+comparing to 8100+ all w/Stock pipe- but aftermarket can
With the TKI- it's only a matter of less than 5 min to change the ratio back and forth....
7 tooth drivers ..... nope not ever again- flatter track angle to the rail tips, easier rolling resistance ( old school again), and just as much clearance as a 3" w/ 7 tooth at the front, that just got into my shop today.
The QD sticking down is more of a concern than the very very minimal of the 8's drop
but that QD pimple,has a custom hard hat on it now from Fire-N-Ice
I'll try to get some pic's
S/C
All I can say for right now is, the motor likes to spin and with not a for sure a 100% correct rpm/ torque at elevation spec ( still digging for that one)- doing what is working-and getting very respectful results... I don't want to have it diggin to china- but it could be better suited for tree bangin'( on/of throttle) with the next step of gearing-
For boondocking group- but I think we have that one pretty much addressed with this driver swap/ clutching / and gearing.
Sled is lovin 8300+comparing to 8100+ all w/Stock pipe- but aftermarket can
With the TKI- it's only a matter of less than 5 min to change the ratio back and forth....
7 tooth drivers ..... nope not ever again- flatter track angle to the rail tips, easier rolling resistance ( old school again), and just as much clearance as a 3" w/ 7 tooth at the front, that just got into my shop today.
The QD sticking down is more of a concern than the very very minimal of the 8's drop
but that QD pimple,has a custom hard hat on it now from Fire-N-IceI'll try to get some pic's
S/C
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The reason(old school I guess)reducing the angle of the track coming off the drivers,rolling resistance, and spearing the track has been lessened also
All I can say for right now is, the motor likes to spin and with not a for sure a 100% correct rpm/ torque at elevation spec ( still digging for that one)- doing what is working-and getting very respectful results... I don't want to have it diggin to china- but it could be better suited for tree bangin'( on/of throttle) with the next step of gearing-
For boondocking group- but I think we have that one pretty much addressed with this driver swap/ clutching / and gearing.
Sled is lovin 8300+comparing to 8100+ all w/Stock pipe- but aftermarket can
With the TKI- it's only a matter of less than 5 min to change the ratio back and forth....
7 tooth drivers ..... nope not ever again- flatter track angle to the rail tips, easier rolling resistance ( old school again), and just as much clearance as a 3" w/ 7 tooth at the front, that just got into my shop today.
The QD sticking down is more of a concern than the very very minimal of the 8's drop
I'll try to get some pic's
S/C
Where r those pics?
