Exactly, if it is clutched so the motor is not loaded and you gear up you may actually gain track speed but if you gear down first and then load the motor with proper cluthcing you will be way ahead.
SLP clutch kit on the 24 boost
- Thread starter ryang85
- Start date
yes
R
Reddragon800
Well-known member
I would like to jump in on this conversation.
I think understanding what gearing is in each sled and what that equates to in an efficient transfer of power will help. We can all agree the closer to 1-1 or exactly 1-1 is the most efficient way to transfer power on a CVT system. I attached a chart that illustrates the shift points and corresponding track speeds in each 1/10 of a shift and what is needed to achieve 1-1.
The Boost makes good power but the clutching is horrible and the gearing IS TOO HIGH. Achieving 1-1 or 120KM/h track speed in a climb in fresh snow will NEVER happen. On a trail or poaching a track it will, but not in fresh snow.
With Correct clutching and gearing and more power you can achieve 1-1.
I attached 2 photos. One of a boost with a 10hp tune, geared right, clutched right - full shift, Second is a axys 850 with a boondocker sidekick turbo with bad gearing and clutching - barely getting half shift.
Lots to think about here, but allows to understand how much tracks speed and power is required to get these sleds to perform there absolute best.
I think understanding what gearing is in each sled and what that equates to in an efficient transfer of power will help. We can all agree the closer to 1-1 or exactly 1-1 is the most efficient way to transfer power on a CVT system. I attached a chart that illustrates the shift points and corresponding track speeds in each 1/10 of a shift and what is needed to achieve 1-1.
The Boost makes good power but the clutching is horrible and the gearing IS TOO HIGH. Achieving 1-1 or 120KM/h track speed in a climb in fresh snow will NEVER happen. On a trail or poaching a track it will, but not in fresh snow.
With Correct clutching and gearing and more power you can achieve 1-1.
| Polaris 850 Matryx Stock clutching | ||||||
| Boost QD2 | Kurts Geardown | Skidoo 850T | ||||
| 22/50 - 145KMH | 29/69 - 139KMH | 21/53- 122KMH | ||||
| 2.27 ratio | 2.38 ratio | 2.52 ratio | ||||
| 1-1= 120KMH | 1-1 =115KMH | 1-1 = 101KMPH | ||||
| 8500 RPM | 8500 RPM | 8000 RPM | ||||
| Belt pressure lbs | Shift location | |||||
654 | 0 | 0 | 0 | 0 | ||
621 | ||||||
594 | 0.1 | 13.18 | 12.64 | 11.09 | ||
571 | ||||||
550 | 0.2 | 26.36 | 25.28 | 22.19 | ||
530 | ||||||
513 | 0.3 | 39.54 | 37.92 | 33.28 | ||
497 | ||||||
483 | 0.4 | 52.72 | 50.56 | 44.37 | ||
470 | ||||||
458 | 0.5 | 65.9 | 63.2 | 55.46 | ||
446 | ||||||
436 | 0.6 | 79.08 | 75.84 | 66.55 | ||
427 | ||||||
418 | 0.7 | 92.26 | 88.48 | 77.64 | ||
411 | ||||||
403 | 0.8 | 105.44 | 101.12 | 88.73 | ||
397 | ||||||
391 | 0.9 | 118.62 | 113.76 | 99.82 | ||
385 | 1-1 Shift | 1-1 Shift | 1-1 Shift | |||
380 | 1 | 131.8 | 126.4 | 110.91 | ||
375 | Half overdrive | Half overdrive | Half overdrive | |||
370 | 1.1 | 145 | 139 | 122 | ||
| Full Over Drive | Full Over Drive | Full Over Drive | ||||
I attached 2 photos. One of a boost with a 10hp tune, geared right, clutched right - full shift, Second is a axys 850 with a boondocker sidekick turbo with bad gearing and clutching - barely getting half shift.
Lots to think about here, but allows to understand how much tracks speed and power is required to get these sleds to perform there absolute best.
Thank you for taking the time to show the numbers to prove what you are saying. Unfortunately you will be met with "that guy" who says he has always geared up his turbos to load the motor and get way more track speed. He won't be able to prove anything only tell you that you know nothing and he has more experience because he has always done it that way.
Don't listen to him as there are many who silently appreciate it.
Don't listen to him as there are many who silently appreciate it.
Last edited:
If I put a Kurt's gear down on my boost, how would I need to change my clutching? I have a 23 boost with a vohk 91 tune and their clutching
I don't think Kurts gear down is low enough. Mine is at 2.52:1 and feel it would even be better geared lower. (higher ratio, lower final speed) 165 Series 9 track.
Stop bickering and get a sled with equal weight riders and one geared down and one with stock gearing or geared up and pull same hill same time in 2ft of fresh or more especially if theres obstacles that you have to work around ya know like anything but wide open bowls and see who wins. My money is on geared down go ahead ask me how I know.
R
Reddragon800
Well-known member
Dont need to change a thing. Just run it as is.
Similar threads
