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

[Dynamo^Joe]

Today we had some fun working for about 6 hours on the new 850 turbo sled. I been working on the clutching for a turbo for a few seasons now and wanted to see the fruits of it on the stock skidoo turbo 850 sled. Kinda had it about 90% setup already but wanted to vidya some of the last testing before I send kits out to test guys in snowmobile land.

James arrived, unloaded the sled and was excited to get started.
James) "This turbo sled goes real good Joe"
Joe) ok, if you think so. We'll see about that. I know they go but after you run your sled then drive Corey's sled, you may re-evaluate your conclusion.

The track is 660 and in the back where you can't see is a small circle track, kind of a mini-sno-x track. Just basically a bunch of bumps you can play with the throttle a bit and get into some fresh snow on the infield.

First I got James to slowly drive his sled around the track back and forth and then go into the crosser section in the back and giver a bit over the bumps. Then take Corey's xPert and follow the same course.
James was shocked at the engagement speed and how Corey's pulled off the bottom end.

Next test. Lets drive side by side up and down the race track and switch sleds each round and do this 4x because i want him to get the feel at part throttle speeds of both sleds. Then after James taking his for a rip again, then Corey's for a rip, he said "Make mine like Corey's"

DRAG TIME - Notice how I pulled up to James on the start, then hit reverse and I give him 1 full length start. My ski tips to his rear bumper. He's asking me "you sure about this" I said "im going to eat your lunch by the 200 foot mark". We did 4 races switching lanes, and he could pick the best line and give me the worst line, I wanted James to make the rules and give me 1 disadvantage. By 70 feet I reeled him in and going by at 100 and by 200 foot cone, the xPert made at least a 1 sled GAP between it and the turbo. And that's not my words, I was not looking back. I dont know how far I was ahead. That's James saying "at least a sled length gap between us"

Ok Sled in garage and start to put the clutch kit in. Instead of taking the muffler out, James massaged the shield to have a relief for the top shaft tool. Once he did that, we were on our way to installing.

First RIP
Stock 984 ramps
Engagement speed around 3400 the sheave touches the belt and 3500 sled starts to move
97 grams total arm weight (Pivot bolt, Popeye arms, 984 ramp, clicker assembly weighed on a scale_)
Clicker 3
Out for a drag run to 60mph, ran at 8000~8100 rpms. James ran 8200.
Back in shop and add 1.8g to the pivot bolt.
I could get 8000 on track spin and 7900 and pull like a b@stard.
James on sled could see 8100 on track spin and hookup 7900 and pull like a b@stard.

After doing 4 more runs alone, James come back and said "wow, i see what you mean by stock dont pull after 40mph and now it pulls smoothly till i let off"

Now, for someone to get uppity about me doing all of this at 900 ft elevation and in that snow and label this effort "flatlander". Ermm...i'll remind you that xPert has the same clutch kit as guys are running in Utah and Colorado at 12k feet. Just the pivot weight is lower as elevation increases.

Every clutch kit that you've ever read about of mine since 1999 has started at this garage and drag strip. you gotta start somewhere. Once I have something that feels good compared to stock at this site, then the "Test kits" go out all over God's creation. I get feedback and do something with that feedback to trim off and commission a kit.

Now James turbo sled can take me by a hood length to 3/4 length to the 100 ft mark and by 200 feet, he's gapped me 1 sled gap. Holy cow does that turbo sled rip now. HAHA.

 

[Boost Monster]

You the man Joe! Can’t wait to get my kit from you and make my T850 even better! Thanks for all your hard work buddy!

 

[skegpro]

That's an impressive difference in engagement.

 

[maxwell]

im so confused. So how will the clutch kit react when there is a 40hp difference between those 2 machines at 8000ft? Just remove weight?

 

[pfi572]

You being funny Sean ?!!
If making same power as testing it will require very little adjustment.
Might require a bit due to heavier load from deep snow , but very little .
The cool thing about not losing hp at elevation.

Good Job Turkey

 

[Caper11]

im so confused. So how will the clutch kit react when there is a 40hp difference between those 2 machines at 8000ft? Just remove weight?

Adjust the clickers.

 

[maxwell]

You being funny Sean ?!!
If making same power as testing it will require very little adjustment.
Might require a bit due to heavier load from deep snow , but very little .
The cool thing about not losing hp at elevation.

Good Job Turkey

Sorry i thought he had the same parts in both i re read.

 

[Dynamo^Joe]

Its like this

sea level
xpert 160hp (minus 5hp)
turbo 165hp

1000 ft asl
xpert 155hp (minus 10hp)
turbo 165hp

2000 ft asl
xpert 150hp (minus 15hp)
turbo 165hp

3000 ft asl
xpert 145hp (minus 20hp)
turbo 165hp

4000 ft asl
xpert 140hp (minus 25hp)
turbo 165hp

5000 ft asl
xpert 135hp (minus 30hp)
turbo 165hp

6000 ft asl
xpert 130hp (minus 35hp)
turbo 165hp

7000 ft asl
xpert 125hp (minus 40hp)
turbo 165hp

8000 ft asl
xpert 120hp (minus 45hp)
turbo 165hp
-----------------------line in the sand-------------------
9000 ft asl
xpert 112hp (minus 46hp)
turbo 158hp

10000 ft asl
xpert 108hp (minus 45hp)
turbo 153hp

11000 ft asl
xpert 103hp (minus 45hp)
turbo 148hp

12000 ft asl
xpert 97hp (minus 45hp)
turbo 143hp

Lets say both sleds left sea level and were able to drive up to 12000 feet in one day.
Every 1000 feet, the xPert will have to pull out around 0.9 grams to 1.1 grams pinweight to achieve 7950 rpms again. The Turbo will not till around 8000 feet.

By the time the turbo gets to 9000 feet, the operator has a choice. Either clicker up to 4 OR pull out 0.9~1.1 gram pivot bolt weight.
From 8000 feet and higher, then BOTH sleds will have to alter their pivot bolt weight and/or clicker position to maintain 7950 rpms on average until maximum elevation.

In an ideal world, What you see in the drag race video, that turbo should act with the same performance at 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000 and not have to chagne the clicker. If we were running that race at 1000 feet where I am and then helicoptered up to 7000 feet, according to BRP, the sled should have the same performance at 1000 feet where you watched the video.

I dont know how i can explain this in any other more easy to understand terms.

Those are BRP hp claims on estimate.
I have a ROTAX aircraft engine manual that has a chart of power loss percentage per elevation and the "rate" at which the power loss changes at around 8000 feet, the hp loss is more than 5hp per 1000 feet after 8000 feet.

 

[skegpro]

Its like this

sea level
xpert 160hp (minus 5hp)
turbo 165hp

1000 ft asl
xpert 155hp (minus 10hp)
turbo 165hp

2000 ft asl
xpert 150hp (minus 15hp)
turbo 165hp

3000 ft asl
xpert 145hp (minus 20hp)
turbo 165hp

4000 ft asl
xpert 140hp (minus 25hp)
turbo 165hp

5000 ft asl
xpert 135hp (minus 30hp)
turbo 165hp

6000 ft asl
xpert 130hp (minus 35hp)
turbo 165hp

7000 ft asl
xpert 125hp (minus 40hp)
turbo 165hp

8000 ft asl
xpert 120hp (minus 45hp)
turbo 165hp
-----------------------line in the sand-------------------
9000 ft asl
xpert 112hp (minus 46hp)
turbo 158hp

10000 ft asl
xpert 108hp (minus 45hp)
turbo 153hp

11000 ft asl
xpert 103hp (minus 45hp)
turbo 148hp

12000 ft asl
xpert 97hp (minus 45hp)
turbo 143hp

Lets say both sleds left sea level and were able to drive up to 12000 feet in one day.
Every 1000 feet, the xPert will have to pull out around 0.9 grams to 1.1 grams pinweight to achieve 7950 rpms again. The Turbo will not till around 8000 feet.

By the time the turbo gets to 9000 feet, the operator has a choice. Either clicker up to 4 OR pull out 0.9~1.1 gram pivot bolt weight.
From 8000 feet and higher, then BOTH sleds will have to alter their pivot bolt weight and/or clicker position to maintain 7950 rpms on average until maximum elevation.

In an ideal world, What you see in the drag race video, that turbo should act with the same performance at 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000 and not have to chagne the clicker. If we were running that race at 1000 feet where I am and then helicoptered up to 7000 feet, according to BRP, the sled should have the same performance at 1000 feet where you watched the video.

I dont know how i can explain this in any other more easy to understand terms.

Those are BRP hp claims on estimate.
I have a ROTAX aircraft engine manual that has a chart of power loss percentage per elevation and the "rate" at which the power loss changes at around 8000 feet, the hp loss is more than 5hp per 1000 feet after 8000 feet.

What are the mechanical details of the clutch kit installed on both sleds?

 

[Dynamo^Joe]

Im at 900' asl so the grams on non turbo sled vary with elevation.

The xpert is the standard kit for the 965 ramp
https://www.ibackshift.com/comersus/store/comersus_viewItem.asp?idProduct=131
99 grams (total ramp weight on scale; Popeye arms, pivot bolt, spacer weight, ramp, clicker assy)
145/365 primary
clicker 3
Dalton yellow/orange
D5 helix

The turbo uses the stock 984 ramp
same secondary guts as the 850 summit 3.0 track kit.
99 grams (total ramp weight on scale; Popeye arms, pivot bolt, spacer weight, ramp, clicker assy)
clicker 3
Different primary spring.

Im fiddling with 2 primary springs now. Test kits are fedex out today to my test guys in snowmobile land, Washington, Colorado, BC, Alberta.
Goal is to get the 984 ramp to 3000 rpms or less. My own sled is at 2200 rpms, but i dont think I can get there with the 984 ramp, but i'll try to get as low as I can.

Im going to test after with my own primary clutch on it with 2200 rpm engagement and i think the turbo will pull it no problem.

 

[catrutt]

What does it do to belt temp?

 

[Dynamo^Joe]

If it works out like my standard kits then you'll see lower belt temperatures than stock. You have to keep in mind though, belt temps are from a lot of "happy throttle" so when you lose 200 rpms full throttle, then you've over heated the belt from going past the point of the belt maintaining its hot hardness. Keep on going with the 200 rpms loss at full throttle and expect to go over the handlebars when the belt blows.

Instead of the clutching giving out on you and stalling the track out, now you'll give up before the track speed will, because you know when to give up; stuck is stuck - which I promise you, you'll get "picture of the day" stuck with my kit.

For what you the rider can control, in the end, the belt temperatures you see are up to you and your throttle choices. My kit, nobody's kit is a cure to lower temperatures. My opinion is the "root of high temperatures" is the alignment of your individual clutches when under load. I have too many customers who've done the grip and rip alignment procedure and lowered 70 to 100 degrees compared to before the gnr alignment. One of my test guys said he's done 17 gnrs now. Another in Calgary has done 8. I have a decent size list with feedback that I can't deny the alignment and movement of stock is the root cause of high temperatures IF the operator wants to bring the temps to belt destruction.

You want to lower temperatures on clutching? Stay stock and spend the money/time/effort/energy on doing the Grip-And-Rip alignment procedure to lower your belt temperatures. Then after that, the sky is the limit with clutch tuning.

 

[skegpro]

I am seeing alot of guys pulling 8100 rpm , clicker #1 on the stock turbo setup.

Wonder if that was intentional on doos part.

 

[Dynamo^Joe]

To balance your question out; Take into account, each sled is an individual with its conduct and the location where its at (snow type/rider weight with gear..etc) the sum of all the loads determine the engine speed at full throttle.
Now ask the opposing question; how many sleds are at 7900~7950 rpms?

...and factor in the idiom "no news is good news"

 

[maxwell]

Clicker 1 for 6 days now. 8000rpm all day long +-100

 

[tex78]

Im at 900' asl so the grams on non turbo sled vary with elevation.

The xpert is the standard kit for the 965 ramp
https://www.ibackshift.com/comersus/store/comersus_viewItem.asp?idProduct=131
99 grams (total ramp weight on scale; Popeye arms, pivot bolt, spacer weight, ramp, clicker assy)
145/365 primary
clicker 3
Dalton yellow/orange
D5 helix

The turbo uses the stock 984 ramp
same secondary guts as the 850 summit 3.0 track kit.
99 grams (total ramp weight on scale; Popeye arms, pivot bolt, spacer weight, ramp, clicker assy)
clicker 3
Different primary spring.

Im fiddling with 2 primary springs now. Test kits are fedex out today to my test guys in snowmobile land, Washington, Colorado, BC, Alberta.
Goal is to get the 984 ramp to 3000 rpms or less. My own sled is at 2200 rpms, but i dont think I can get there with the 984 ramp, but i'll try to get as low as I can.

Im going to test after with my own primary clutch on it with 2200 rpm engagement and i think the turbo will pull it no problem.

Why so low of engagement rpm??

 

[Cableguy]

DJ do you think the multi angle helix will be a good upgrade to the turbo power

 

[Dynamo^Joe]

Why so low of engagement rpm??

Sorry Tex, you know me, there is rarely short answers. hahaha

My research on engagement speed started when i was out testing my 17 G4 sled new. I was doing sidehilling on kind of setup snow, having a problem with the sled going too fast. Engagement speed was around 3600 rpms and the handlebars always felt like jerking out of my hands. Then when i got enough throttle control to go across a 150ft long bank, the belt was starting to smell so much, my buddy track poaching me could smell it. The engine speed at part throttle is high when going 7~8mph across the sidehill. Its too dang fast.
Engage speed too high and part throttle engine speed is high; belt stinkin to high heaven. Have to stop in the middle of the sidehill to shut off and cool it off.
The problems found let me to create a different left arm called "Popeye's left arm" which eliminated the clutch surging in and out of engagement and a side benefit, the engagement speed lowered with them.

So...Im always trying to find the limits of something. Ive made my living off doing opposite of what Big mouths have said "you can't do that" or "this is mandatory" or "that wont work" or "you dont need those angles" or "too strong of springs" or "too much pinweight" or "too low of gearing"....or or or. If someone says something like that "can only go left" you can bet your arse im gonna spit on the ground and say "im going right".

• its how I make my living. People say no, I say, we'll see about that.

If you have ever got to try a 600etec Tundra Xtreme, its engagement speed is 2800 rpms. The start from stop ability is pretty amazing. Grant you, it has a wide track and good flotation that way, its not tippy. Designed for driving over trees like a bulldozer and getting into places, difficult for a tippy summit. Skandic and TundraX, you can mow down alders, stop on top of them and even back up if you have to. The engagement speed allows you to pick your way through trees that no other sled can do better - or so we believe up to this point.

Since I been experimenting with engagement speeds, i've got 2200 rpms on my sled right now and my goal is 2000 rpms.
I have the engagement speed low so I can "Alder Bash". I can mow down alders now and stop on top of them. If i cant get around some, I can back up and choose another path of alders to mow over. Its the stop-after-start ability that im trying to see the limitations of.

Here is an example.
I gps'd out a really big swamp that was only accessible by going through 950 ft (GPS feet) of alders. I told Corey to wait to see how far I can get in and if you hear me shut off, im sawing trees. In the picture, can you see the end? hahaha. It was so thick I had to use GPS to navigate through it.


About 1/2 way through Corey could not hear me anymore so he reluctantly followed me in and we found a patch of swamp system the snow was waist deep. When you stopped, your front end submarine. hahaha

• The lower engagement speed slows me down and i can make a plan "b" better. The crawling ability to climb a bank off a creek is the best my sled has ever climbed.
• The stop-and-start ability i have more control over than a higher engagement speed.
• When im on a bunch of alders, I can feather the throttle to move ahead over them and not spin out.
• When im have to make a 10 point turn using reverse, i have a more easy time to start to get a run at backing up.
• When going around trees i can barely fit between, i can lean the chassis up and feather throttle, not spinning to squeak through
• Wrong foot forward I can go much slower and maintain momentum and control from washing out.
• Neutral position with my sled on edge, I can drive much slower and a more straight line and keep the sled moving, but slower.
• I have more confidence in my ability now to get across something i might not have gone with higher engagement speed because I can gage the distance of the line im going to pull, to the trees/rocks below that i want to stay away from, I can slow down and make it.
• I dont have Carl Kuster or any other of the skidoo xPert riders skill. Im just "Joe Slow"

Im converting all the guys in my group to 2800 or less. My test guy Pat out in Washington with his Turbo is already liking 3000 rpms.(Temporarily trying a different ramp)
But, im going to get my way with this stock 984 ramp to achieve at least 3000 rpms.

That alder bashing was worth the chance for 2 solid hours of fun in our own find.

 

[Dynamo^Joe]

DJ do you think the multi angle helix will be a good upgrade to the turbo power

I dont know. People who own and drive the turbo sled say "amazing" and "cant get any better than this" or "can it get better than this?"

I dont use them. I'll test them stock first and eventually find deficiencies here and there from using over time. Like my G4 kit, I drove the sled for 3/4 of a season, bone stock before i started to play with the clutching. At first i was so scared of how good i thought my G4 was that I may not be able to make a clutch kit for it and improve over stock. But, drive it as much as I can, every weekend, sometimes during the week, sometimes 2x/weekend and eventually you make the sled groan at 7500 because your ability is better. You get your sea-legs with the sled and your ability catches up with the capacity of the sled. Then there are some things you know you can do but the clutching is holding you back. You get a deficiency here and a deficiency there and eventually a "multi angle" helix floats to the surface.

I develop and make multi angle helixes for my kits and that's what works best for me personally. I pass them on to my test guys which in some-way-shape-or-form passes on to my customers.

 

[skegpro]

Clicker 1 for 6 days now. 8000rpm all day long +-100

Think you could pull more weight yet?