Helix effect on elevation changes?

[DKP]

All im going is by your words...
-full on the heel
-Where, if I grab full throttle, she looses RPM
-Give a stab of throttle. Sometimes it hit rpm. Sometimes bark and be 4-500 low
-Running 8100. Should be 8400 with pipe.

I dont know what or where you have the composites inside the weight.
I'll assume you have all the weight in hole #1.

This season, go out for your typical riding day as-it-is right now [if the composites are in hole 1]. Get your sea legs with riding again and find the deficiencies again, the things you did not like of the engine speed's conduct.
Then a second day, go out, same thing and get about 1/3 of the riding day in and stop. Move all the composites to position 3. Go ride. See the difference between 1 and 3 and record your new deficiencies.
You might find wanting to put weight in 2, or 2 and 3 or split it between 1,2,&3.

you must, you must, you must write a track speed down where you see the deficiency you want to clean up/solve/fix...
Aaen says you need 2 data inputs, 1 rpms, and 2 track speed. Without the track speed, you cant identify where any part in your clutches are being used in relative to your throttle input.
Example; "where i grab full throttle, she loses rpms - happened at estimated 38mph track speed.
With that track speed, you can estimate very close to how much spring force is being used, which helix angle is being used, where the spider roller on the cam arm [flyweight] is.

• If you dont measure it, you can't see it.

Hmmph, your issue(s) is why I just like to stick to old fashioned Aaen tuning; with stock OEM or fairly stock profiles, and not have composite weights at all. I'd rather have a selection of springs with different start and final forces to nail down a calibration.
To me you have an engine power shape problem. Its like having a dart board hangin by a rope, swinging like a pendulum and you're trying to hit the bullseye; basically trying to chase your engine power shape. The power shape is moving around and you're trying to chase it with clutch tuning. Id say go back to stock as possible, then nail down your clutch calibration; then change to the aftermarket exhaust parts.
View attachment 392457
Aaen says you need 2 data inputs, 1 rpms, and 2 track speed. Without the track speed, you cant identify where any part in your clutches are being used in relative to your throttle input.

Well. In your photo. Those are my ramps. And from heel to tip iirc I am 4-3-1 total of 65g I also have a set of 4 hole 850 ramps from a friend that need bushings replaced. That's easy. I'll have to study the photo. I was under the impression that tip weight only affected high rpm. And heel was engagement/low throttle. I like my engagement now. It's perfect. It's 2/3-wot I feel is off.


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[Dynamo^Joe]

Seen in lower track speeds, like 0mph~25mph
4,3,1 [most aggressive bottom end, lugs engine off bottom, seen in lower track speeds]
3,3,2
3,2,3
2,3,3
1,3,4 [least aggressive bottom end, revvy engine off bottom end, seen in lower track speeds]


Seen in highest track speeds, like 50mph~75mph
4,3,1 [pulls less harder on top end, can feel "revvy" at higher track speeds]
3,3,2
3,2,3
2,3,3
1,3,4 [most aggressive top end, can feel "lugging" and slow to recover engine rpms at higher track speeds, poor backshift]

 

[TreeThrasher]

Off the top of my head and very generalized, I’d say you don’t have enough tip mass for the helix split you are using…so you create a very inconsistent setup when torque and horsepower changes with elevation.
At 5500 to 7k feet you have a shift curve that matches up to your engine. My gut tells me that you are shifting the clutches a bit further down lower and running right out of load with the clutch. You are out into 36 degrees of helix which isn’t much,
And you don’t have much tip weight to help drive the shift.

I would use less helix split with more percentage of tip mass to balance the clutches over a wider elevation.

 

[Dynamo^Joe]

I would use less helix split with more percentage of tip mass to balance the clutches over a wider elevation.

Buddy, can ya give an example helix angle based on the helix (48-36 .36) he mentioned?

 

[TreeThrasher]

44-40 .36 worked real well in the piped 800 axys I clutched before I switched to paragon…paragon used a 58-55 very successfully. Too much helix split with the rapid rpm acceleration of the 800 axys motor will create a finicky setup…what the OP is experiencing

 

[Dynamo^Joe]

44-40 .36 worked real well in the piped 800 axys I clutched before I switched to paragon…paragon used a 58-55 very successfully. Too much helix split with the rapid rpm acceleration of the 800 axys motor will create a finicky setup…what the OP is experiencing

DKP mentioned 48-36 .36
what you would use as an example(s).... [neglecting paragon, maintaining what DKP has]

Bigger middle number to close the gap between the first number
48-38 .36, or
48-40 .36, or
48-42 .36...etc, or

Smaller start number to close the gap between the second number
44-36 .36
42-36 .36
40-36 .36

 

[Sheetmetalfab]

Off the top of my head and very generalized, I’d say you don’t have enough tip mass for the helix split you are using…so you create a very inconsistent setup when torque and horsepower changes with elevation.
At 5500 to 7k feet you have a shift curve that matches up to your engine. My gut tells me that you are shifting the clutches a bit further down lower and running right out of load with the clutch. You are out into 36 degrees of helix which isn’t much,
And you don’t have much tip weight to help drive the shift.

I would use less helix split with more percentage of tip mass to balance the clutches over a wider elevation.

I would second the less helix split with the Axys 800 / SLP_ pipe.

heel heavy weights were also a mismatch with this motor / pipe.

even distribution of magnets or even tip heavy worked well for me.

 

[Sheetmetalfab]

DKP mentioned 48-36 .36
what you would use as an example(s).... [neglecting paragon, maintaining what DKP has]

Bigger middle number to close the gap between the first number
48-38 .36, or
48-40 .36, or
48-42 .36...etc, or

Smaller start number to close the gap between the second number
44-36 .36
42-36 .36
40-36 .36

personally starting from the OP's situation I would try the 44-36 .36.

but none of the parts listed here match my preferred Axys 800 SLP pipe setup. (Indy specialties mtn 1 helix, springs and weights)

 

[DKP]

Well this is now giving me food for thought and highly educational. Could I go buy Indy Dans kit. Yes and I'll prob still eff with it. But looks like I can get custom made for $159 Canadian. Dual cut so I can have 2 in one. Now where to start. Both posters here have but different numbers. Split is closer. But might try get both in one 44/36 and 44/40. Go from there


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[Dynamo^Joe]

Buddy....Be specific when it comes to helix angles.
44/40 is a 44, 43, 42, 41, 40, indicates you're using a progressive helix.
44-40 .XX shows you're using a 2 angle helix. [2 angle step start]

 

[DKP]

Ya I know that. But since everything that has been talked about was a .36, and I was typing on my phone, I omitted it. Also been talking with my supplier, he going to send me a bunch of springs for both clutches that they have used in testing their different pipe and head combos. Spring changes first, then can possibly nail down a direction to go with Helix if needed

 

[Dynamo^Joe]

A secondary spring with higher forces give higher engine speed at part throttle.
Example; say a 160/260 has an exertion of 210 pounds at 35mph track speed. At steady part throttle lets say you have 5600 rpms.
180/260 [raising the start 20 pounds] has an exertion of 220 pounds at 35mph track speed. At steady part throttle lets say you have 5800 rpms. That 10 pounds increase at 35mph track speed can give up to 200 rpms higher engine speed at part throttle.

If you can, know the forces of the spring you're using right now.
If you can, know the forces of the springs they're going to send you.

Remember the rule of thumb about "spring forces determines engine speed at part throttle", and, try to know/find out the forces of the springs the supplier's sending you,
THEN according to the facts of how your sled runs right now and the way you want it to run, you could tell the supplier to "dont send me all those springs. Send this spring and keep that spring".

Ideally the supplier could have told you the secondary spring you're using right now, and, also tell you the forces of the springs they're sending, and...
ideally the supplier should know "spring forces determines engine speed at part throttle" and send an appropriate spring according to the facts of your deficiency.

he he

 

[StuckDownHill]

Been cruising the forums to try and learn a bit about clutching. Came across this conversation and realized that clutching is gawd damn witchcraft.

 

[DKP]

Revisiting this thread. But from my starting of it, I have discovered that I am geared too low for the SSI pipe. Back to stock pipe and trying to get a baseline clutching setup, then try the SSI again. I have a TKI belt drive now, 26 and 27 top gear. Pipe DID NOT like the 26 2.42 ratio. Stock wasnt bad but had really light primary spring and weights, Gear up 27t 2.33 Same as the Kurts I was running last season. Added more primary spring and weight. 120/340 (120lb spread) and 63.4g total. 4 hole weights now, so 0 1 1 1 I was loading Heel so much before. Playing with the placements. Secondary is 48/36 .36 with 140/220 spring. For this trial anyways. I haven'tordered a helix or anything yet. I like the quick spool down low, Helps the sled pop up and get on edge easier. I am at the belief that my clutch kit supplier, while it worked. Was nowhere near the right way. My choice to gear down is one I always have had. I don;t trail run except the 26Km up and down to alpine. Don't need high speed on a Mtn sled. I would rather use more clutch in the deep, even tho it costs engine RPM and fuel on trail. I miss the TRA clickers for that for sure. 1 on trail 3-5 up top. I'm really hoping I can use the SSI pipe, TRS said they are a biatch to tune and most took them off. But I really notice the midrange extra pull over the stock. Right where I ride most. But it HAS to also perform a WOT pull as there are some climbs in the trees one needs to be full pin.

 

[Dynamo^Joe]

Been cruising the forums to try and learn a bit about clutching. Came across this conversation and realized that clutching is gawd damn witchcraft.

Clutching is simple
2 stroke Engines are black magic, a dark art.

Technical

Learn more about your Ski-Doo and LYNX 850 Clutch kits with our Technical blog.

www.ibackshift.com

Read my 3 articles of the turbo can, the y-pipe, the 850 pipe.
...now that's witchcraftery....

 

[DKP]

Clutching is simple
2 stroke Engines are black magic, a dark art.

Technical

Learn more about your Ski-Doo and LYNX 850 Clutch kits with our Technical blog.

www.ibackshift.com

Read my 3 articles of the turbo can, the y-pipe, the 850 pipe.
...now that's witchcraftery....

Yup. Totally agree!!! And clutching to a motor pipe combo you have no idea what it is, It's some dark art too.


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