850 turbo 165 (stock clutch) vs Xpert 165 (iBackshift)

[Dynamo^Joe]

Sir, thanks for asking.
Gearing up is a local thing. Your track speed is local. Im at 900 feet and Im happy if i get 43~45mph track speed (154/3.0). My snow is wet/heavy/cascade concrete type, its not vapour or cotton ball. My sled augers a slot into the snow. My cousin rides with me. Same sled, same kit, he's geared 21-53, im 19-53. His sled rips with that gear, but i feel the difference in mine. What i find the difference, mine vs. Reggies is when i need to go around, say, a tree and need to get the skis up in the air to pull the sled for a "plan b" kind of turn, i think mine augers down in the snow better so i can yank the sled over quicker, but that's me and my style.

Next location; my buddy here from Thunder Bay (19/154/3.0) went to Utah last month and in rode in their "Vapour" snow. Mike said when he could see the tach he's getting 75kmh with 120hp at 8500 feet.

30+hp difference but we're getting the same track speed.

Kevin my test guy in Wasilla gets 80kmh (50~54mph) track speed at 1100~3000 feet (154/3.0)

Track speed is a local measurement. If you feel you can gear up then go for it. I have guys in Norway, Sweden who've geared up in their snow type and it worked well for them.

The clutch kit is a palette to work with and from that point on can tune specifically for yourself. Try gearing up one tooth.

 

[Dynamo^Joe]

Low elevation drag racing is a starting point, but doesn't really simulate real mountain conditions. At 6500' your down to 138hp. Climbing in 24-30" of fresh on a 30 degree slope loads the clutch set up way more than a drag race ever will. So what ever set up you were using for drag racing won't work for a mountain set up. Joe has been at this a long time and I'm sure he has "his" kit figured out. My opinion is that just removing pivot weight from the original set up isn't the way to go. I would run a completely different set up for low elevation then high. I wonder who is testing his stuff in Edmonton. Would be interesting to see how it works compared to how i have my clutch kits. Thats my 2cents.

Please dont infer im alleging you of copying or anything of that sort. Im just presenting a chapter out of my tuning handbook. From chapter 44 "problem solving, sorting facts" Its my opinion that in the category of clutch tuning, tuners should only test their own settings with the wide range of people/circumstances who are going to use the product.

Excerpt...
There are two answers to this question
Question) How did you actually learn how to build a clutch kit?

Answer 1) I bought other peoples kits and tested them in secret and found one that stood out then peppered it with my own pride found a few parts that were the same but different colors to disguise the kit so i looked like I developed it, and called it "Johnny's clutch kit". And then when those people have a new kit, i get it and test it and then if i find something good i like i switch out the parts again and keep calling it "johhny's kit"

Answer 2) I read books and talk to people about clutch tuning and tried to learn on my own and there are some great books out there and there's lots of smart people I tapped into on their own knowledge. Then I went on my own and I learned a tremendous amount when i "iterated through my own problems" figuring out what parts i can set together that will work for my end users. The problems i had with my own parts caused me to solve problems to change to a different part.

It's kind of like almost any of quality knowledge; you gain knowledge when you struggle with a problem, that's when you understand it and you've a pretty good grasp of it, what you "created", not copied.

That's one of the ways when you can interview someone who works on "creating a tune", you ask them "tell me about the problems that they worked on and how they solved them" And if someone was really the person has solved it they'll be able to answer multiple levels. They'll be able to go down to the brass tacks and tell you how many layers are in the onion.

And if they weren't able to do this, they'll get stuck on a difficult question and then you can say...
...this person was not really the person who solved it because anyone who struggled hard with a problem knows how to solve it and NEVER forgets it.

Now if you were able to get both tuners, the one with answer 1 and the other with answer 2 in a room, in front of you and ask them questions; you'll see the grand canyon gap of knowledge between the two of them. Because one is going to shut up and the other is going to enthusiastically walk you through the problems they seen and how they solved it.

My opinion is if you are developing your own setup, then you have to "race" against yourself and do enough testing that other people using your stuff, (not other kits) present a problem to you, that you have to iterate...

iterate; a procedure in which repetition of a sequence of operations yields results successively closer to a desired result

...through your clutch kit owners problem, solving their problem, solves your problem and makes the kit better with each problem solved.

See, the lens that most people look through only "sees the kit", but the reality is its just a bunch of parts. What the owner is dealing with is the fruits of your own labor.
In the end, they're buying YOU (the builder) they just happen to get a box of parts to go with it.
So now when they have a problem, the root of the problem is they've bought someone else's work that you aren't able to troubleshoot and solve. You did not go through the problems "the creator" did. There is a categorical difference between clever and wisdom.

...end of excerpt

So.....I think a guy who wants to build clutch kits is wasting their time, doubling the time of testing when they go up against a competitor product that requires knowledge to troubleshoot problems. You done testing and did not learn anything.

I can take any kit of mine and you can tell me a problem at say 47mph track speed.
As long as I know your gear ratio, I know….
• What primary spring force is being used at 47mph track speed
• What secondary spring force is being used at 47mph track speed
• What helix angle is being used at 47mph track speed
• Where the roller is on the ramp in the primary clutch at 47mph track speed.
• Where the belt is located in the primary clutch at 47mph track speed.

….i can figure out every component right away.
https://www.ibackshift.com/article/helix--cam-189.asp

and now you see an example of the grand canyon gap of knowledge. you have to know your own s4it.

Take 2 of your kits, one in your sled and one mounted in another sled. Put a driver on the other sled who's 80 pounds heavier than you and you are going to see a problem or two. The more heavy operator presents some facts (problems) and now solve it; and your tuning knowledge will increase because you solved a problem. My opinion is yer wasting your time when running up against someone's kit because you just don't really know what they have and if its even setup properly and you are not the one who says "their stuff is setup properly" and when you have a problem, you aint gonna know what to do to solve it; the moves will be "guessing". Some people buy kits because their sled runs poorly and think clutching is going to solve their problem, when it was worn out clutch parts, improper octane, muffler not working properly...a host of other problems, but you only see the sled, dont know if there is something wrong with the sled in the first place.

Then you'll say "their stuff is junk"
no...
...you're guilty of what you blame them.

 

[pfi572]

Well said .

 

[snochuk]

Nice to se thorough explanations from DJ on what makes kits tick.

 

[dragonweld28]

That was quite the answer. Every tuner has a direction. I like comparing and seeing the difference. So, i take that as a no... lol.

 

[Dynamo^Joe]

Buddy...my test guy just goes riding and does his own thing with his closed group of guys. No stickers, no advertising, I like my test guys to keep low key and do their own thing. Chris has been watching this post and kinda giggling about it. Just happy im able to post and not have guys chew me a new arse.

 

[kanedog]

That was quite the answer. Every tuner has a direction. I like comparing and seeing the difference. So, i take that as a no... lol.

Over your head gif.

 

[niner]

Over your head gif. https://media1.giphy.com/media/3o6ozq0pgIDt5j6N8I/giphy.gif

I hope for dynamo Joe’s sake your not one of his test riders...

 

[jpmez69]

I hope for dynamo Joe’s sake your not one of his test riders...

I don't think Dynamo Joe is into making stock clutching worse...

 

[Dynamo^Joe]

I seen a trenching post.
I think this will help lower trenching with the 850 turbo.
2900 engagement now and the sled moves at 30~3100 rpms.
My goal is to be lower than a 900 Expedition at 2800 rpms.
https://www.youtube.com/watch?v=uRKSIV_V-yo

 

[skegpro]

I seen a trenching post.
I think this will help lower trenching with the 850 turbo.
2900 engagement now and the sled moves at 30~3100 rpms.
My goal is to be lower than a 900 Expedition at 2800 rpms.
https://www.youtube.com/watch?v=uRKSIV_V-yo

I like

 

[ktmsx350f]

forsure. going to grab some heavier bolts

Why not get a different spring and get 2 birds stoned at once. Lower engagement rpm will load the turbo and make boost faster and different finishing pressure to bring clicker back to 3. With good clutching I be willing to bet you could spool way faster stock 6200 rpm to make boost is really high, makes it smooth but slow into boost vs good clutching which should easily be into to boost by 5200-5500 rpm like any other setup especially with a slightly smaller turbo.

 

[turboetech]

I spent the weekend at Mcbride Renshaw with a 850 turbo saw rpms of 8450 at clicker 1 so I just throttled back a bit to avoid pingin off the rev limiter all weekend I have increased bolt weight from original 13 grams to a 20 gram total weight hope I’m in the ball park for next ride every thing I have read on snow and mud is how dialed these turbo sleds are.... this one I’m on sure needs some clutch tuning hope 7 grams increase will get me in the ball park of clicker 3

 

[1709]

I spent the weekend at Mcbride Renshaw with a 850 turbo saw rpms of 8450 at clicker 1 so I just throttled back a bit to avoid pingin off the rev limiter all weekend I have increased bolt weight from original 13 grams to a 20 gram total weight hope I’m in the ball park for next ride every thing I have read on snow and mud is how dialed these turbo sleds are.... this one I’m on sure needs some clutch tuning hope 7 grams increase will get me in the ball park of clicker 3

What altitude were you at? not many primary spring choices, stock is 150 – 350, I put in 120 – 350 and added the 33mm pin bolts, stock are 26mm, the 33mm are 2.1 grams heavier,
I am on clicker 1 revving at 7900 RPMS. at 5200 feet. IMHO the stock clutching is for 8000 feet and above, that`s what they made the turbo 850 for, high elevation. and for the turbo to pull you need to load the engine.

Never been to Mcbride Renshaw, but would love to come and ride there, maybe we could hook up and you could show me the area sometime. thanks.

 

[Caper11]

I spent the weekend at Mcbride Renshaw with a 850 turbo saw rpms of 8450 at clicker 1 so I just throttled back a bit to avoid pingin off the rev limiter all weekend I have increased bolt weight from original 13 grams to a 20 gram total weight hope I’m in the ball park for next ride every thing I have read on snow and mud is how dialed these turbo sleds are.... this one I’m on sure needs some clutch tuning hope 7 grams increase will get me in the ball park of clicker 3

I think you will be fine. Hopefully its too heavy so you can click up.

 

[Dynamo^Joe]

What altitude were you at? not many primary spring choices, stock is 150 – 350, I put in 120 – 350 and added the 33mm pin bolts, stock are 26mm, the 33mm are 2.1 grams heavier,
I am on clicker 1 revving at 7900 RPMS. at 5200 feet. IMHO the stock clutching is for 8000 feet and above, that`s what they made the turbo 850 for, high elevation. and for the turbo to pull you need to load the engine.

What shop did you get a 120/350 from?
There is a 120/300
I looked at Dooey, spi, dalton..etc. Is that a 120/300?

 

[1709]

What shop did you get a 120/350 from?
There is a 120/300
I looked at Dooey, spi, dalton..etc. Is that a 120/300?

Yes made a mistake, it`s a 120 -300 ski doo spring, did drop engagement a little, but not as much as i would like.

 

[Dynamo^Joe]

https://www.youtube.com/watch?v=yimohyWvu2c

 

[Dynamo^Joe]

I uploaded a couple of G4 clutch part install videos (recorded fall 2018) on my Ytube page also.

 

[Caper11]

Awesome vid for comparison Joe! Good work. Thanks for sharing.