Ski-Doo Snowmobiles Forum banner
1 - 20 of 84 Posts

·
Metalhead
Joined
·
9,232 Posts
I want to discuss stock....stock stock stock....800R 2008~newer summit.
I like to focus on "Snow depth" and not on elevation. I know elevation increases and power decreases but rather put a thinking cap on "snow depth" or "Snow load" - Neglect elevation. The reason I ask is that it is normal to observe that (snow load determines track speed), does not matter what elevation, you are in your own area and you observe your results. Whether you are are at sea level or 13000 feet, what track speed did you see and what is the highest track speed you have seen.

I have talked to guys who have run in jan/feb with (normal-to-see) track speeds from 28~35mph and rarely get over 38mph in snow on a climb with a stock 800R. [Washington/Wyoming/Montana]

I have talked to guys who have run in jan/feb with (normal-to-see) track speeds from 38~45mph and rarely get over 50mph in snow on a climb with a stock 800R. [Golden/Revelstoke/Maine/Newfoundland]

I have talked to guys who have run in jan/feb with (normal-to-see) track speeds from 45~55mph and think it's impossible to get over 60mph track speed on a climb with a stock 800R. [Alaska/BC/Maine/Sweden/Norway]

Alright...set all opinions aside and answer...[Think "stock 800R"] & [In your own particular region]
What is the highest track speed you have seen while climbing?
What is the highest track speed you have heard of your friend or whoever, has seen while climbing?
What is the highest track speed you see on the trail or road to get up to the location you drive in?

Can I ask you to put your answer in a format:

Region -
Month -
Snow type -
Snow depth -
Track speed -
Highest road speed -
Comments:

Example:
Cooke city
Jan/Feb
Fresh heavy powder
3.5 ~ 4.6 feet
29~33 mph
Highest road speed is 70mph
Snowed for a whole day and left 4 feet of fresh powder, hard to maintain rpms, difficult to get on top of snow....tons of fun.

I am going to work on something this summer for a handful of summit owners to test out on their 2008 and 09 summits for the next coming season.
 

·
Registered
Joined
·
100 Posts
I want to discuss stock....stock stock stock....800R 2008~newer summit.
I like to focus on "Snow depth" and not on elevation. I know elevation increases and power decreases but rather put a thinking cap on "snow depth" or "Snow load" - Neglect elevation. The reason I ask is that it is normal to observe that (snow load determines track speed), does not matter what elevation, you are in your own area and you observe your results. Whether you are are at sea level or 13000 feet, what track speed did you see and what is the highest track speed you have seen.

I have talked to guys who have run in jan/feb with (normal-to-see) track speeds from 28~35mph and rarely get over 38mph in snow on a climb with a stock 800R. [Washington/Wyoming/Montana]

I have talked to guys who have run in jan/feb with (normal-to-see) track speeds from 38~45mph and rarely get over 50mph in snow on a climb with a stock 800R. [Golden/Revelstoke/Maine/Newfoundland]

I have talked to guys who have run in jan/feb with (normal-to-see) track speeds from 45~55mph and think it's impossible to get over 60mph track speed on a climb with a stock 800R. [Alaska/BC/Maine/Sweden/Norway]

Alright...set all opinions aside and answer...[Think "stock 800R"] & [In your own particular region]
What is the highest track speed you have seen while climbing?
What is the highest track speed you have heard of your friend or whoever, has seen while climbing?
What is the highest track speed you see on the trail or road to get up to the location you drive in?

Can I ask you to put your answer in a format:

Region -
Month -
Snow type -
Snow depth -
Track speed -
Highest road speed -
Comments:

Example:
Cooke city
Jan/Feb
Fresh heavy powder
3.5 ~ 4.6 feet
29~33 mph
Highest road speed is 70mph
Snowed for a whole day and left 4 feet of fresh powder, hard to maintain rpms, difficult to get on top of snow....tons of fun.

I am going to work on something this summer for a handful of summit owners to test out on their 2008 and 09 summits for the next coming season.
Conssitant track speed in freshly fallen powder, no base and normal moisture content for my 08 154 is 32-38 mph. This is observed in the months of Jan and Feb and I view this has a full load on the engine. My 07 XRS 151 in same conditions would usually see 25-30 mph. Top speed on my 154X is 96MPH compared to my 07 at 81mph, my 08 hauls.

Now, when you throw some traction at my sled (hardpack) the speeds increase dramatically. Take 12-18" of fresh on top of hard snow and I will se 50-55 mph track speed but defiantely not a full load on the motor, can tell by the way it backshifts and the sound of the engine.

You can determine that my clutching is more suited for snow conditions that have some base and in full powder conditions I am a little aggressive, but set-up snow has been more common for me than bottom less powder. Rpm's have remained farily consistant though between the different ranges of snow, 8050 (deep powder)-8350 (powder with hardpack under) all the time on clicker 3.

To me the snow makes all the difference in track speed, clutching cannot perform the same in all different types of snow (load) conditions.

Anytime I can achieve over 40MPH while climbing with a stock 800 in a full load condition I am very happy, it is just hard to be happy though.

If I were to ride bottom less powder all of the time I would gear the sled down to a 19-47 and look for a better helix for the powder load.

-Frog
 

·
Registered
Joined
·
1,521 Posts
hungry horse montana
december
2 feet of heavy powder
44 to 48mph, on two stock machines
85mph rosd speed
6500'
nice day with a ton of snow prior
 

·
Metalhead
Joined
·
9,232 Posts
Discussion Starter · #4 ·
jan/feb
no base and normal moisture content
08 154 is 32-38 mph.
top speed 96MPH

month?
fresh on top of hard snow
12-18"
50-55 mph
...definetely not a full load on the motor, can tell by the way it backshifts and the sound of the engine.

Rpm's have remained farily consistant though between the different ranges of snow, 8050 (deep powder)-8350 (powder with hardpack under) all the time on clicker 3.
Frog writes: To me the snow makes all the difference in track speed, clutching cannot perform the same in all different types of snow (load) conditions.
Joe writes: Do you think a helix/spring combination can have a blend of details that would cover a wider range of snow types? yes or no?

Frog writes:Anytime I can achieve over 40MPH while climbing with a stock 800 in a full load condition I am very happy, it is just hard to be happy though.
Joe writes: Is it hard to be happy because the track speed you see has hit "equilibrium"?

Frog writes:If I were to ride bottom less powder all of the time I would gear the sled down to a 19-47 and look for a better helix for the powder load.
Joe writes: For your 08XP, what gearing do you have in it right now? Would you gear this lower for bottomless?
 

·
Berwyn rocks......
Joined
·
935 Posts
Summit X 146", MBRP can, DJ helix, purple/blue primary spring, 16.8 gr pin weight, 19/45 gearing, 288 belt.

Region - northwestern Alberta, riding at 1000-3000 feet mainly in river hills, pipelines, and snow covered fields.
Month - December and January
Snow type - loose, fine powder snow w/no cohesion
Snow depth - 16-36 inches
Track speed - climbing @ 43-47 mph, on the flat across the fields in loose snow @ 63-70mph
Highest road speed - 23/45-95mph, 21/45-97mph, 19/45-88mph, gearing had no effect on powder snow track speed.
Comments - clickers on 2-3, low speed boondocking and climbing is fantastic, getting my doors blown off across a field of fresh snow on top end by an '02 700 Summit 144" is aggravating to say the least.

Region - Valemount/McBride BC
Month - February
Snow type - heavy powder, w/some cohesion
Snow depth - 24-48 inches
Track speed - 40-45mph
Highest road speed - 88mph
Comments - clickers on 4-5, absolutely no complaints while riding in the mountains, track speed was instantaneous and held throughout the climb until the bitter end with a slight loss just before turnout in fairly set up snow.
 

·
Registered
Joined
·
100 Posts
Frog writes: To me the snow makes all the difference in track speed, clutching cannot perform the same in all different types of snow (load) conditions.
Joe writes: Do you think a helix/spring combination can have a blend of details that would cover a wider range of snow types? yes or no?

Frog writes:Anytime I can achieve over 40MPH while climbing with a stock 800 in a full load condition I am very happy, it is just hard to be happy though.
Joe writes: Is it hard to be happy because the track speed you see has hit "equilibrium"?

Frog writes:If I were to ride bottom less powder all of the time I would gear the sled down to a 19-47 and look for a better helix for the powder load.
Joe writes: For your 08XP, what gearing do you have in it right now? Would you gear this lower for bottomless?
Yes, but with limitations. The combo may work good in all types of conditions but may be short compared to a set-up that is specific towards a certain snow condition, will depend on what the buyer wants. Some may be happy with a set-up that works good in every situation some may want more for climbing, tough answer. I think it will come down to how much give and take you can do between powder and hardpack snow to reach a good quality "medium" in an all around set-up, consistancy is the rule and RPM's vs track speed is the dictator. With my XRS last year I fought rpm issues like most but had to sacrifice track speed to achieve rpm's. If both can be kept at an optimal level then you have a winner.

A balance point, yes. More track speed can be achieved but with any change in "load" the rpm's will be all over the board. With what there is to work with it is the best that can be achieved.

I have 19-45 now, I have tried 21 (stock), 20 and now the 19 and the lower I have gone the better performance I have achieved in bottomless powder. I believe that there is more room to gear down when running this type of snow, keeping the clutches cooler and allowing the clutch to work more consistantly.

To me much of the fight is the TRA. The upshifting qualitys of this clutch really hinder it's performance in a mountain situation. It's mass alone prohibits backshifting and causes us to tear our hair put trying to find a good clutch set-up. IMHO the TRA is one of the toughest clutches to tune.

-Frog
 

·
Metalhead
Joined
·
9,232 Posts
To me much of the fight is the TRA. The upshifting qualitys of this clutch really hinder it's performance in a mountain situation. It's mass alone prohibits backshifting and causes us to tear our hair put trying to find a good clutch set-up. IMHO the TRA is one of the toughest clutches to tune.

A long time ago I thought the same thing and after learning more about principle of operation of the parts i've changed my mind.
Now after 1/3 of winter of pulling out my hair with some models I believe more than ever how good the clutch is and easy to calculate a calibration.

Helix angle controls 2 elements of rpms. (backshift)
1] sustained rpms under wide open throttle [Constant rpms]
2] Rate of rpm acceleration under wide open throttle. [rpms per unit of time] [rpm motion resulting from throttle position]

It's mass alone prohibits backshifting
...If backshift is poor, then what can you do with helix angle and/or spring force to promote backshift?
Can the angles be reduced/increased?
Can spring forces be reduced/increased?

IMHO the TRA is one of the toughest clutches to tune
...Does it matter the brand of sled/clutches?
If a yamaha sled come from factory with calibration that works satisfactory in small window of operation [toughest clutches to tune] then this can be said for any system?

A yamaha nytro w/stock clutch from factory can do excellent in snow in low track speeds however observe around 40+mph track speeds the sled loses 500~800 rpms and have to turn out, cannot maintain track speed.
So now what to do?
Tuners will pull flyweight out and now overrev until about 40mph track speed then maintains proper rpms however the 0~40mph is poor acceleration.
Change flyweight, no clickers to change.
Is this a tough clutch to tune - yes or no?

A skidoo xp w/stock clutch from factory can do excellent in snow in low track speeds however observe around 40+mph track speeds the sled loses 300~500 rpms and have to turn out, cannot maintain track speed.
So now what to do?
Tuners will pull flyweight out and now overrev until about 40mph track speed then maintains proper rpms however the 0~40mph is poor acceleration.
Is this a tough clutch to tune - yes or no?

Ok then....on yam/doo why was there low rpms in the initial run at 40mph track speed?

The yam has a straight 39 and at 45mph track speed the rpms diminish - What angle was being used at 45mph?
The Doo has a straight 42 and at 45mph track speed the rpms diminish - What angle was being used at 45mph?

Helix angle controls 2 elements of rpms. (backshift)
1] xxxxxxxx xxxx xxxxx xxxx xxxx xxxx [xxxxxxxx xxxx] (less angle produce more rpms & larger angle produce less rpms)
2] xxxx xx xxx xxxxxxxxxxxxx xxxx xxxx xxxx xxxx. [rpm acceleration] [rpm motion resulting from throttle position]

IF you observe low rpms at 45 mph
THEN what will you do with the helix angle? Raise or lower?

Spring force controls 2 elements of rpms. (backshift)
1] xxxxxxxx xxxx xxxxx xxxx xxxx xxxx [xxxxxxxx xxxx] (less force produce less rpms & larger force produce more rpms)
2] xxxx xx xxx xxxxxxxxxxxxx xxxx xxxx xxxx xxxx. [rpm acceleration] [rpm motion resulting from throttle position]

IF you observe low rpms at 45 mph
THEN what can you do with the spring force? Raise or lower?

........if the calibration can be changed then why would a system be tough to tune if you follow principles?

weight determines rpms...
angle determines 2 elements of rpms...
spring forces determine lever force and rpms...
ramp angles do this...
fluctuating rpms are caused by...
center of gravity moved here changes the rpms to....
etc...

So now if a tuner walks into tuning a sled and make a test run, gather the data then determine "rpms are wrong" or "temp too high" or this or that, can always look to principles to tune and not opinions. Now you pit the principle against the result to make a calibration change - does it matter if its a yamaha cat poo doo?
 

·
Registered
Joined
·
6,394 Posts
On the Yamaha what if you installed the heavy rivet closest to the pivot pin and the lighter rivet in the out side hole or even, no rivet at all in the out side hole. Would it hold the 500 rpm on the climb and not have to turn out?

Never did like the straight Yami helix just did not work at all!

My cousins Attack, pulls good shift speed on the trail but pull off in the pow and is only pulls 9000rpm and bachshift is non existant.

On the Ski-doo you have the option of turning up the clicker on the hill to capture the 500 rpm, maybe loose some acceleration but you do not have to go back to the truck load up and back to town and drill out rivets like on the Yamaha. After two trips to the truck and back to town for clutch tuning on the Yami now we are out of rivets and have to hunt down a Yamaha dealer to buy more rivets for tuning in tomorrow session.

The progresive helix is good on the Doo also, not a fan of straight helixes, less you are running a turbo. How is that Turbo Nytro clutching session going Joe?
 

·
Registered
Joined
·
18 Posts
Valemount, BC
Feb, Mar.
2 to 3 feet powder, medium consistency
48 to 50mph while steep climbing 8200 rpm
No chance to open it up on the trail.
20 tootth upper with 16.5grams pinweight
154x(still needs clutch aligned as temps are high and cogs on inside of belt are wore flat on inner edge)
 

·
Registered
Joined
·
362 Posts
fernie BC
Jan/feb
3+feet soft powder
42 to 45 mph track speed.
154x stock
road ride
stock speedO 98mph MBRP can\
stock speedO 101mph Stock can
ran back to back two times this was at 1600ft elevation.
stock gives faster top speed.

giddyup
 

·
Registered
Joined
·
2,363 Posts
Joey,.... How are ya?
Man, we have been busy testing these Summit XP's this year.... 3 Summit 154's in our group.

#1 is completely stock with 16 grams pin weight, no vents, stock gearing, QRS, MBRP can.
Region - Valemount
Month - March 7/8
Snow type - heavy powder on base
Snow depth - 18"
Track speed - 50-51
Highest road speed - 90
Comments: Temperatures were 5 celcius and clear skies, sled in clicker 4 running 8200-8300 rpm, 166 belt.

#2 is moving 18 grams pin weight, vents, quick clickers, 19/45 gearing, QRS, Neils can.
Region - Valemount
Month - March 7/8
Snow type - heavy powder on base
Snow depth - 18"
Track speed - 48-49
Highest road speed - 88
Comments: Sled pulls hard, running clicker 4 at 7000', 8250rpm, 166 belt

#3 is running 18 grams, vents, quick clickers, 21/45, Team secondary, Neils can.
Region - Valemount
Month - March 7/8
Snow type - heavy powder on base
Snow depth - 18"
Track speed - 45
Highest road speed - 90
Comments: On clicker 4 could only pull 43 mph, clicker 5 went 45 mph, clicker 6 went 47 mph. 377 belt.

Next time we are out, in a couple weeks, sled #1 and #2 will remain the same. #3 will have 20/45 gearing and a (48-44-33),(48-42-33) twin trax helix and try a few different springs to try to get its track speed even with the QRS equiped sleds.
Test dummies are us.....



Sled #1 in front, #2 in middle and #3 in back.....
 

Attachments

·
Metalhead
Joined
·
9,232 Posts
Discussion Starter · #15 ·
On the Yamaha what if you installed the heavy rivet closest to the pivot pin and the lighter rivet in the out side hole or even, no rivet at all in the out side hole. Would it hold the 500 rpm on the climb and not have to turn out?
Principle...
Center of gravity closer to the clutch shaft; The arm force will be less aggressive in low shift ratios - Arm force increases as shift ratio increases
Center of gravity away from the clutch shaft; The arm force will be more aggressive in low ratios - Arm force decreases as shift ratio increases.

I would agree that moving lever's center of gravity away [Ski-B; closest to the pivot pin] the arm force will decrease as shift ratio increases.
The amount of rpms drift would be less or if the c-of-g was moved enough or just right amount, then the rpms will not drift lower.

Ski-B; The progresive helix is good on the Doo also, not a fan of straight helixes, less you are running a turbo. How is that Turbo Nytro clutching session going Joe?
Joe; Heading to Revvy this week and have my packsack full of clutch goodies. Will see after the weekend.
 

·
Registered
Joined
·
106 Posts
[quote name='Dynamo^Joe' date='Mar 18 2008, 09:50 AM' post='1733009']
I want to discuss stock....stock stock stock....800R 2008~newer summit.
I like to focus on "Snow depth" and not on elevation. I know elevation increases and power decreases but rather put a thinking cap on "snow depth" or "Snow load" - Neglect elevation. The reason I ask is that it is normal to observe that (snow load determines track speed), does not matter what elevation, you are in your own area and you observe your results. Whether you are are at sea level or 13000 feet, what track speed did you see and what is the highest track speed you have seen.
Can I ask you to put your answer in a format:

Here is some info for you.

Region - Valemount / Mcbride B.C.
Month -Febuary
Snow type - Heavy Powder
Snow depth - 2'~3' with a good base under that.
Track speed - 45-47 mph
Highest road speed - 86 but had to let off
Comments: 800r with a mbrp can, D.J. helix, Purple/Pink primary spring, 15.6 grams of pin weight, 19/45 gearing and a 377 belt. 210 miles on the new belt and still looks great. While climbing track speed was at 45 most of the time but when the snow set up and the belt broke in good I was seeing 47. I had my clickers set at 3. It would pull hard the end of my climb but i made sure to have enough left to turn. On the way down one rap of the flipper and the engine would take over and hold the sled pretty good just like you said.

Region - Tumber Ridge, B.C.
Month - March
Snow Type - Hard Pack with six inches of new snow
Snow Depth - a average of 24-30 inches
Track speed - 47-50
Highest road speed - Boondocked all day never got to ride at road speed
Comments: Well we rode another 45 miles in meadows and small moutains. I had to run the clickers on 2 and would pull 48-49 mph @ 8100 - 8200 rpm. Primary was getting pretty warm.

I am going to the moutains again this weekend > I changed my gearing from a 19 top gear to a 21. (i'll see what that changes) There will be a few 800r's there so i will try to keep some numbers, one other with a DJ kit as well.
 

·
Registered
Joined
·
289 Posts
stock 08 163X.....thing can..25mm set screws!

Region - revy
Month -dec- early feb
Snow type - fresh
Snow depth -3ft+
Track speed - 37-39mph
Highest road speed -85+ at home on fields
Comments:clutches not aligned..get very hot. rpms all over the place! some of the rpm drop may be due to intake plugging from deep powder(not too sure).
 

·
Registered
Joined
·
145 Posts
stock 08 154 24mm set screws 19t gears
region Mcbride 6000-7000 feet
clutches aligned to spec.
40-43 m.p.h. at 8200r.p.m. climbing
never got to open it up on the road
this was in feb. and march with 1 foot pow. on set up base
used clicker 3 or 4 r.p.m. fluctuated lots
07 with can pulled me on the flats or climbing
used 377 belt last time lots of heat but held up
kind of felt like 166 belt performed better but would use one every ride
 

·
Metalhead
Joined
·
9,232 Posts
Discussion Starter · #19 ·
Thanks for the info so far gents...
Anyone else, please continue to add your info.
I need to build a good statistic.

I know the gear ratio range is from 21:45 to 29:49. I am gathering your data to see the average low track speed and the average high track speed [in various loaded conditions]
 

·
Registered
Joined
·
436 Posts
Hi Joey,
Heres mine,

19t, 19 grams pin weight, quick clickers, 19/45 gearing, Your kit, MBRP can.
Region - N.E. Oregon 4500-7000'
Month - January-February
Snow type - Bottomless powder, fresh
Snow depth - 36"~ 48"
Track speed - 45~48
Highest road speed - 83~85
Comments: Sled pulls hard, running clicker 3 at 5500', 8200rpm digital, 377 belt
 
1 - 20 of 84 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top