Clutch - Clutching - T3 specs - 438 ramps

[Dynamo^Joe]

This 2015 sled will surely rip in stock form like all the earlier years of 154, 163, 174 3" paddle tracks that inspired the making of it. If it weren't' for the aftermarket in the past, creating products that can be put together to form such a sled (for the last 4 years already), we prolly would not have it "factory direct".

T3 Eur 21:51 x 112P chain - 7T x 3" driver
T4 Eur 19:49 x 110P chain - 7T x 3" driver

40 helix
blue secondary spring
391 belt

438 ramps. With the track length and paddle depth, the amount the track will engage with the snow, It certainly was proper to go the route of using the 438 start of the ramp.

Congratz to BRP for a superb sled that streaks past the other OEM's.

Back in the day, one of my test guys Lee went to the 3” paddle. Lee being 6 foot something and 270ish with gear and avvy pack helped me to figure out the start of some ramp testing.

At first with the kit and stock track he could do a 180 at near to correct engine speed. Hitting the throttle, pulling the sled over he could hear the ETEC grind to less than 8000 (7800~ish) and climb to 8000 about ½ way through the turn.

• Installs 3” paddle

Just as in a legal matter (clutch law) there is a: Problem - Cause - Solution

Problem
Lee performs same operation on a nice crisp clear blue sky day morning - Hitting the throttle, pulling the sled over he could hear the engine grind to less than 8000 and slowly climb to 8000 after the turn was completed, sled pointing in the opposite direction.

Doing this a couple of times he was able to get a good look at the tach. Hit throttle, lean sled, carve...7500 and slowly climb to 8000. The rest of the shift was deadly as would be with the 3” paddle track. Only complaint was off the bottom end.

Cause
441 ramp angle too steep off the start

Apply these facts to the Aaen’s "Laws & Rules of Thumb" (tuning handbook)

Aaen Handbook – Vol 2007 – pg 13 bottom.
The Driver(Primary) The driving clutch has one main purpose: to control the engine speed in all shift ratios. Etc...etc... Keeping the engine on the power curve and pulling hard is the main purpose of the driving clutch.

• Lets only adjust the settings in the required (problem) shift ratio (low ratio)

Aaen Handbook – Vol 2007 – pg 21
The driving clutch is required to take care of all the speed variations from stand still to top end

...did he say “from stand still”???

• Low ratio

Aaen Handbook – Vol 2007 – pg 28~29
We want the force to decrease as the weight swings out, so the increased radius has to be compensated for by a cam(ramp) shape which transfers less of the force (allows engine speed to build quicker)

Solution
Ok, then just change the settings where the problem arises. Change the settings at the track speed where the difficulties are.

Low engine speed at the start (low ratio)
Correct engine speed once going

What settings can one change in the low ratio?

- primary spring engagement force

- ramp start angle

- secondary spring start force

- helix start angle

Go from the 441 and change to my “DJ” ramps and do nothing else to the system – hammer down.

Results
Doing this a couple of times he was able to get a good look at the tach. Hit throttle, lean sled, carve...7800 and quickly climb to 8000. The rest of the shift was deadly as would be with the 3” paddle track. No more complaint of the bottom end.

441 vs. 438 Today in 2015
I would say that BRP made a superb move by going from the 441 to the 438 to compensate for the enhanced ground engagement ANY sled-can-make with the 3” paddle. The engine will light up quite nicely when needed and not have slow accelerating engine speed. (remember a 174 up to 3.0 is not new)

I am not going to say the 441’s will be slow to accelerate the engine, no, rather just saying the increased angle of the 438 will reveal a quicker accelerating engine speed if you were to test, directly changing only the ramps out back-n-forth.

Caveat - ramps with humps (like the 438)
There is kind of a provision for using ramps with "humps" at the engagement. The engagement will still be low with the application of the hump. Just want to let the reader know that say if at one time you are on a trail or packed down or beat down path and are going to turn around - If you feel a "chirp" or slight "surge" when the engine speed is at engagement...might even feel a jerking motion when starting to press the throttle.

...Check your belt width and belt deflection.

Once the belt starts to get lower tension between the two pulleys (from wear & improper belt height) the primary clutch lever roller will dwell "to and fro" over top of that hump. the sheave will lightly smack the belt "puk puk puk" as you are starting to turn.

Check the belt tension between the two pulleys and tighten it up and that "dwelling" will disappear.

Hope this information was fun to read for you.

Cya
joey

OH...here is a fun ramp page to look at.

 

[Deep Powder Guy]

Chirps, Surges & Puk, Puk, Puk the 3 bouncing Betty's Doo sing a tune.....Have you or your test rider Lee even had a chance to ride, test and evaluate clutching variations for the 2015 ?

DPG

 

[TJ427]

Thanks for sharing your expertise and helping educate us about clutching!

 

[Dynamo^Joe]

Chirps, Surges & Puk, Puk, Puk the 3 bouncing Betty's Doo sing a tune.....Have you or your test rider Lee even had a chance to ride, test and evaluate clutching variations for the 2015 ?

DPG

In a summit, I've tested the 438 ramp every season since its appearance in 2008. Last season like before, I have test guys with 156, 162 and 174 running 3" tracks and they all cycle through my checklist of "things to run". Ive run them ramps (testing) in a 174 luxobarge since 2010. It ends up going to my mountain ramps as the ramp that pulls off the strongest engine braking to the lowest track speed every time.

Inside the factory stock pulleys - other than the ramps themselves for 2015 all other internal parts are the same back to 2012
-------------------------------------------------------

The point of that post is to illustrate what the angle of the ramp does different than another angle of a ramp. Just like the profile of a cam arm in a Poo/Cat/Yam primary clutch - if you want to change the way the engine accelerates over time in a certain portion of drive ratio - it can be accomplished with the curve of the ramp/cam arm itself. Just know what the "angle" itself does to engine speed acceleration.
Higher angle "quickens" engine speed
Lower ramp angle makes engine speed "less quick" than a higher one.

One does not need to get on a sled to know that "this ramp" will be quicker engine speed than "that ramp" - and neither do you or anyone else reading this page. The Law of the angle of the ramp speaks and can't be changed. To a novice with only the willing to learn, if you explain the law and rule of thumb about what the angles of the ramp does, you can throw 2 different ones at him/her and they'll be able to explain to you of the differences they see (and will come to pass). We dont know the engine speed, but we do know "A" will be quicker and "C" will be less quick.
...the end.

 

[Deep Powder Guy]

In a summit, I've tested the 438 ramp every season since its appearance in 2008. Last season like before, I have test guys with 156, 162 and 174 running 3" tracks and they all cycle through my checklist of "things to run". Ive run them ramps (testing) in a 174 luxobarge since 2010. It ends up going to my mountain ramps as the ramp that pulls off the strongest engine braking to the lowest track speed every time.

Inside the factory stock pulleys - other than the ramps themselves for 2015 all other internal parts are the same back to 2012
-------------------------------------------------------

The point of that post is to illustrate what the angle of the ramp does different than another angle of a ramp. Just like the profile of a cam arm in a Poo/Cat/Yam primary clutch - if you want to change the way the engine accelerates over time in a certain portion of drive ratio - it can be accomplished with the curve of the ramp/cam arm itself. Just know what the "angle" itself does to engine speed acceleration.
Higher angle "quickens" engine speed
Lower ramp angle makes engine speed "less quick" than a higher one.

One does not need to get on a sled to know that "this ramp" will be quicker engine speed than "that ramp" - and neither do you or anyone else reading this page. The Law of the angle of the ramp speaks and can't be changed. To a novice with only the willing to learn, if you explain the law and rule of thumb about what the angles of the ramp does, you can throw 2 different ones at him/her and they'll be able to explain to you of the differences they see (and will come to pass). We dont know the engine speed, but we do know "A" will be quicker and "C" will be less quick.
...the end.

I will agree with you partially....And yes anyone with experience can look at the ramp profiles to determine the shift character of the ramp as you state. It is also far to mention that Doo has an infinite number of ramp profiles to choose from and as you say the 438 has been out for quite some time far longer than 174 tracks have been around. It fair to say that there a several spring,ramp,pin weight combinations that work excellent to rider weight and riding style..which is the beauty of the TRA infinite tuning options and a clicker when you need a pinch of RPM.

I see you also recommend checking belt deflection which I agree with completely...I suggest if your a deep powder rider to check your deflection at some point during the day as well and adjust as needed to optimize performance....During the days ride your belt slightly stretches effecting belt performance.

At the end of the day testing clutch components in the field under actual snow loads is key for the most accurate input. Having some form of adjustability in the clutch is also helpful in order to optimize performance in the field due to constant changing snow condition.

By the way you do know the engine speed 8000 rpm.

DPG

 

[Dynamo^Joe]

Dpg) And yes anyone with experience can look at the ramp profiles to determine the shift character of the ramp as you state.

Joe) and inexperienced – one just has to learn the theory so when a set of facts is presented “slow to accelerate”, “quick to accelerate” then the facts propped up against the clutch law/rule of thumb will show the justification of what angle of what ramp will do what vs. another ramp.
Your fair mentioning’s of spring, ramp, pinweight combos, infinite tuning...etc, are easily discovered information. Thank you.

Dpg) During the days ride your belt slightly stretches effecting belt performance.
Joe) The sae papers I have read this - the belt under load is like a steel band and does not stretch. The aramid fibers are 5x times stronger than steel and do not stretch, nor compress towards each other in the belt. When the casing changes shape it is because of micro dislocations and belt soon fails. I have a whole chapter in my clutch book dedicated to that subject with permission to publish some material from Sae papers of 3 belt manufacturers.

Dpg)By the way you do know the engine speed 8000 rpm.
Joe) the information BRP give me in June reads this - 7900. (print screen attached) Thank you.

 

[Deep Powder Guy]

[QUOTE=Dynamo^Joe;3697348

Dpg) During the days ride your belt slightly stretches effecting belt performance.
Joe) The sae papers I have read this - the belt under load is like a steel band and does not stretch. The aramid fibers are 5x times stronger than steel and do not stretch, nor compress towards each other in the belt. When the casing changes shape it is because of micro dislocations and belt soon fails. I have a whole chapter in my clutch book dedicated to that subject with permission to publish some material from Sae papers of 3 belt manufacturers.

I'm not broad stroking nothing.....Above ^^^^^ you say the belt does not stretch and you outline clearly why you feel the belt does not stretch.....I happen to disagree.

Have you personally tested belts in extreme deep snow conditions conditions ? If you have not and your only basing your knowledge on a SAE sheets from 3 belt manufactures your sorely being mislead.

DPG

 

[Dynamo^Joe]

OT, broad brush stroking by saying "never changed shape in any form" is referring to something only on your own mind as I did not say that, yet are projecting as if I did.

If the belt ideal pitch line circumference is 44 inches it does not grow (example) 44.1 inches, the belt does not grow longer.
If the deflection needs to be adjusted then it is because material is "worn" off the belt. Adjusting belt deflection allows the sheaves to come closer together to compensate and match for a "new-narrower belt width".

 

[bacon1]

This 2015 sled will surely rip in stock form like all the earlier years of 154, 163, 174 3" paddle tracks that inspired the making of it. If it weren't' for the aftermarket in the past, creating products that can be put together to form such a sled (for the last 4 years already), we prolly would not have it "factory direct".

T3 Eur 21:51 x 112P chain - 7T x 3" driver
T4 Eur 19:49 x 110P chain - 7T x 3" driver

40 helix
blue secondary spring
391 belt

438 ramps. With the track length and paddle depth, the amount the track will engage with the snow, It certainly was proper to go the route of using the 438 start of the ramp.

Congratz to BRP for a superb sled that streaks past the other OEM's.

Back in the day, one of my test guys Lee went to the 3” paddle. Lee being 6 foot something and 270ish with gear and avvy pack helped me to figure out the start of some ramp testing.

At first with the kit and stock track he could do a 180 at near to correct engine speed. Hitting the throttle, pulling the sled over he could hear the ETEC grind to less than 8000 (7800~ish) and climb to 8000 about ½ way through the turn.

• Installs 3” paddle

Just as in a legal matter (clutch law) there is a: Problem - Cause - Solution

Problem
Lee performs same operation on a nice crisp clear blue sky day morning - Hitting the throttle, pulling the sled over he could hear the engine grind to less than 8000 and slowly climb to 8000 after the turn was completed, sled pointing in the opposite direction.

Doing this a couple of times he was able to get a good look at the tach. Hit throttle, lean sled, carve...7500 and slowly climb to 8000. The rest of the shift was deadly as would be with the 3” paddle track. Only complaint was off the bottom end.

Cause
441 ramp angle too steep off the start

Apply these facts to the Aaen’s "Laws & Rules of Thumb" (tuning handbook)

Aaen Handbook – Vol 2007 – pg 13 bottom.
The Driver(Primary) The driving clutch has one main purpose: to control the engine speed in all shift ratios. Etc...etc... Keeping the engine on the power curve and pulling hard is the main purpose of the driving clutch.

• Lets only adjust the settings in the required (problem) shift ratio (low ratio)

Aaen Handbook – Vol 2007 – pg 21
The driving clutch is required to take care of all the speed variations from stand still to top end

...did he say “from stand still”???

• Low ratio

Aaen Handbook – Vol 2007 – pg 28~29
We want the force to decrease as the weight swings out, so the increased radius has to be compensated for by a cam(ramp) shape which transfers less of the force (allows engine speed to build quicker)

Solution
Ok, then just change the settings where the problem arises. Change the settings at the track speed where the difficulties are.

Low engine speed at the start (low ratio)
Correct engine speed once going

What settings can one change in the low ratio?

- primary spring engagement force

- ramp start angle

- secondary spring start force

- helix start angle

Go from the 441 and change to my “DJ” ramps and do nothing else to the system – hammer down.

Results
Doing this a couple of times he was able to get a good look at the tach. Hit throttle, lean sled, carve...7800 and quickly climb to 8000. The rest of the shift was deadly as would be with the 3” paddle track. No more complaint of the bottom end.

441 vs. 438 Today in 2015
I would say that BRP made a superb move by going from the 441 to the 438 to compensate for the enhanced ground engagement ANY sled-can-make with the 3” paddle. The engine will light up quite nicely when needed and not have slow accelerating engine speed. (remember a 174 up to 3.0 is not new)

I am not going to say the 441’s will be slow to accelerate the engine, no, rather just saying the increased angle of the 438 will reveal a quicker accelerating engine speed if you were to test, directly changing only the ramps out back-n-forth.

Caveat - ramps with humps (like the 438)
There is kind of a provision for using ramps with "humps" at the engagement. The engagement will still be low with the application of the hump. Just want to let the reader know that say if at one time you are on a trail or packed down or beat down path and are going to turn around - If you feel a "chirp" or slight "surge" when the engine speed is at engagement...might even feel a jerking motion when starting to press the throttle.

...Check your belt width and belt deflection.

Once the belt starts to get lower tension between the two pulleys (from wear & improper belt height) the primary clutch lever roller will dwell "to and fro" over top of that hump. the sheave will lightly smack the belt "puk puk puk" as you are starting to turn.

Check the belt tension between the two pulleys and tighten it up and that "dwelling" will disappear.

Hope this information was fun to read for you.

Cya
joey

OH...here is a fun ramp page to look at.

I'm about the same weight as your test rider. If the internals are all the same from 2012, minus the ramps, could a guy run your mountain ramps, D2 helix and and similar pin weight for 5-8000 feet? What else would you recommend changing? Thanks for your help and advice.

 

[Dynamo^Joe]

I'm about the same weight as your test rider. If the internals are all the same from 2012, minus the ramps, could a guy run your mountain ramps, D2 helix and and similar pin weight for 5-8000 feet? What else would you recommend changing? Thanks for your help and advice.

Howdy.
If you ran my helix then what will happen is you'll end up using about 3 grams more than stock clutching. BRP recommends empty pin 12.4g in clicker 4 (6k~8k)
With that helix you'll have 15.3 grams in clicker 3.
With the 160/350 spring and the stock gearing what happens is in a pull and max out in track speed, the engine speed eventually start to drift lower.

Now because of the heavier flyweight then go to a...
160/380 purple/white or a dalton red/blue 167/390 for (21, 20, 19:49 gears)
160/415 white/blue for (19:51 or any equivalent C3 or 7T driver and lower ratio)

I had dalton make me those springs specifically for my own kits.

Basically when you go past 19:49 then go for the 160/415 primary spring.
thanky

 

[Dynamo^Joe]

If you happen to find a used helix of mine somewhere (D2) then here you go, I help out any way I can and the biggest way is to publish my parts

146~154 800etec
167/390 dalton red/blue or 160/380 BRP purple/white
Whatever grams you need for elevation (setting sheet)
441 ramps or my mountain ramps (415/441 blend)
218/305 dalton red/yellow or 231/303 BRP purple secondary spring
D2 helix

You said 5000~8000, what you'll find is 15.3g for 5000~7000 feet. Somewhere between 7000~7500 you'll end up clicker to #4 to get 7900 again and that will take you to 8000.

163~174 800etec
160/415 primary spring
rest is same as above.

If you have an 800R then clicker 4 for 8200

 

[winter brew]

Looks like they are still using clutch calibration as a factor in meeting sound regs and emissions....good, still room for improvement on the hill.

 

[bacon1]

If you happen to find a used helix of mine somewhere (D2) then here you go, I help out any way I can and the biggest way is to publish my parts

146~154 800etec
167/390 dalton red/blue or 160/380 BRP purple/white
Whatever grams you need for elevation (setting sheet)
441 ramps or my mountain ramps (415/441 blend)
218/305 dalton red/yellow or 231/303 BRP purple secondary spring
D2 helix

You said 5000~8000, what you'll find is 15.3g for 5000~7000 feet. Somewhere between 7000~7500 you'll end up clicker to #4 to get 7900 again and that will take you to 8000.

163~174 800etec
160/415 primary spring
rest is same as above.

If you have an 800R then clicker 4 for 8200

Thank you for your quick response DJ. As far as rollers go, I have a new set of #2 Hytorque rollers. Should a guy use the stockers for a season or should would it be beneficial to switch them out? I should mention this will be a 174 T3.
Thanks again.

 

[Deep Powder Guy]

OT, broad brush stroking by saying "never changed shape in any form" is referring to something only on your own mind as I did not say that, yet are projecting as if I did.

If the belt ideal pitch line circumference is 44 inches it does not grow (example) 44.1 inches, the belt does not grow longer.
If the deflection needs to be adjusted then it is because material is "worn" off the belt. Adjusting belt deflection allows the sheaves to come closer together to compensate and match for a "new-narrower belt width".

Now your saying "material is worn off the belt" in a previous post you say the property within the belt is 5X stronger than steel.

FYI, I don't see any signs of worn material on the sheaves of my clutches.
I have plenty of old belts that I have measured against identical brand new belt and the OD of the older belt is slightly larger which tells me the belt has stretched slightly while the sidewalls of the belt again caused by heat have changed to conform to the angle of the sheaves.

DPG

 

[Dynamo^Joe]

Dan at HT has a bunch of rollers for primary and secondary. I dont see the exact model of his that you are illustrating. I see "2x" so would that be the 2nd O.S. roller?

With that being said I will point out one particular roller regarding my own kits...

I only recommend the original BRP primary clutch rollers because they are 1) the original diameter and 2) they weigh 9 grams. The fact of the original smallest diameter is a benefit with a great degree towards the promotion of quick backshift and strong bottom end acceleration using the most of the meat of the engine's torque curve.

There have been customers who called me up saying (Problem) "engine speed lowering" shortly after maximum track speed achieved in a pull. I go through checklist and find out "ah haa..." (Cause) 10.7 gram rollers.

Solution
Whatever primary spring end force you are using right now (in kit) then take it and raise by 30 lbs.
Example xxx/350 then going to xxx/380
Where the next bigger roller is causing engine speed to drift low, the added end force inputs another 10~12 lbs into the system at the track speed where the problem surfaced.

Or
Change to a less aggressive ramp like going from 441 to a 413 or 415.

Or
Some will gear up a tooth causing to keep the lever away from that portion of the ramp that was pushing too hard with the 10.7g roller.

Or
...return to the 9 gram roller and not look back anymore.

-------------------------------
As far as any other roller size and gram out there, I have no problem with them. Its just I calibrate my kits with the original installed primary clutch rollers to keep the cost of kit down and get good bang for buck out of factory installed parts.

-------------------------------
At one time I made smaller/thinner 8 gram rollers with a machine shop here in the city. After the results of testing around this area (super quick backshift and it opened it up for fiddling with more primary springs to tinker with) I asked CVTech if they could make them for me. Mr. Bernard come back and said "we can make them but expect short life" Then I talk with Dale at Dalton and he ran some numbers too and figured "if they start to break, you'll be in for a world of shiznit"...haha, so I dropped the idea.

 

[Deep Powder Guy]

Looks like they are still using clutch calibration as a factor in meeting sound regs and emissions....good, still room for improvement on the hill.

If your on the hill and in the deep there will always be room to tune IMO. Doo has gotten a lot better over the year with there mountain calibrations. My 14 XM surprisingly out of the box pulled hard and held the rpm.

DPG

 

[Dynamo^Joe]

FYI, I don't see any signs of worn material on the sheaves of my clutches.
DPG

OT, that is because you did not trigger a scenario which belt mfgr's call "greasing". Two scenarios cause "greasing" where belt residue is on the sheave surface that comes off with "elbow grease"

Your pulley cavity area under the belt guard is not shiny anymore unless you clean it every pass - there has been a mist of belt vapour that descends and deposits on every part, aluminum (guard) and plastic underneath your hood.

 

[bacon1]

Dan at HT has a bunch of rollers for primary and secondary. I dont see the exact model of his that you are illustrating. I see "2x" so would that be the 2nd O.S. roller?



With that being said I will point out one particular roller regarding my own kits...



I only recommend the original BRP primary clutch rollers because they are 1) the original diameter and 2) they weigh 9 grams. The fact of the original smallest diameter is a benefit with a great degree towards the promotion of quick backshift and strong bottom end acceleration using the most of the meat of the engine's torque curve.



There have been customers who called me up saying (Problem) "engine speed lowering" shortly after maximum track speed achieved in a pull. I go through checklist and find out "ah haa..." (Cause) 10.7 gram rollers.



Solution

Whatever primary spring end force you are using right now (in kit) then take it and raise by 30 lbs.

Example xxx/350 then going to xxx/380

Where the next bigger roller is causing engine speed to drift low, the added end force inputs another 10~12 lbs into the system at the track speed where the problem surfaced.



Or

Change to a less aggressive ramp like going from 441 to a 413 or 415.



Or

Some will gear up a tooth causing to keep the lever away from that portion of the ramp that was pushing too hard with the 10.7g roller.



Or

...return to the 9 gram roller and not look back anymore.



-------------------------------

As far as any other roller size and gram out there, I have no problem with them. Its just I calibrate my kits with the original installed primary clutch rollers to keep the cost of kit down and get good bang for buck out of factory installed parts.



-------------------------------

At one time I made smaller/thinner 8 gram rollers with a machine shop here in the city. After the results of testing around this area (super quick backshift and it opened it up for fiddling with more primary springs to tinker with) I asked CVTech if they could make them for me. Mr. Bernard come back and said "we can make them but expect short life" Then I talk with Dale at Dalton and he ran some numbers too and figured "if they start to break, you'll be in for a world of shiznit"...haha, so I dropped the idea.

Yes, I am referring to the 2nd oversize roller.

Thank you for clarifying! Stock it will be! You're a huge help and it's much appreciated.

 

[Deep Powder Guy]

OT, that is because you did not trigger a scenario which belt mfgr's call "greasing". Two scenarios cause "greasing" where belt residue is on the sheave surface that comes off with "elbow grease"

Your pulley cavity area under the belt guard is not shiny anymore unless you clean it every pass - there has been a mist of belt vapour that descends and deposits on every part, aluminum (guard) and plastic underneath your hood.

I don't recall ever hearing the word "greasing" that's a new one for me......when a belt is brand new belt dust from the cords on both sides of the belt wall will make a mess. Once the belt is properly broke in and taken shape to the sheaves the belt dust is all but gone...And when the sheaves get hot the rubber compound from the belt side walls can and will transfer a fine film of residue hard to see by the eye on the sheaves....I personally like to dress my sheaves before each ride using some 600 grit and brake cleaner.

DPG

 

[Deep Powder Guy]

DJ I'm curious have you ever marked your sheaves, ramps & helix prior to riding and than taken apart the drive & driven to visually inspect the shift out ? Especially in a deep snow scenario.....I recommend everyone do this it truly gives you a birds eye view of what's occurring within your setup under load and extreme deep snow conditions.

I mention this because having photos demonstrating the result might be helpful to those seeking higher knowledge. Especially comparing trail condition results to deep snow conditions results.

If you bought a brand new sled do this on your first ride out than do it again after 300 miles to determine any change and adjust accordingly.

DPG