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

pfi572

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Who gives a **** what the mph is when I am going by you noodles with a set up sled ?!!
Went by plenty of so called fast set up sleds doing less mph then they had been jabbering about .
Good job Joey
 

1709

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The only people that have to buy a clutch kit from some one else are those that don`t know how to clutch their sled. then they say Oh it`s way better. stock sucks, No people that do not know how to clutch their own sled SUCK.
 

Lund

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<<< .That seams to me to be a fair speed for that hp.. They say it's making 170hp, and with skis so far in air, your only utilizing 1/3 of track.. >>>

So you check your track speed with the skis so far in the air your only utilizing 1/3 of track. I think this is where the problem is, people check their track speed different then other people, most of us that have 850T know what the true track speed is, it`s 78 to 80 Klms = about 50 Mph. NA 850 are about 44 Mph,
with about 30 to 35 HP difference.

I agree 100% with what you say, 60mph (100kph) with 165-70hp is unattainable unless your on less then favorable snow on a climb. Then you might see those numbers but it will not be consistent. The numbers you mention are more realistic to all the custom builds we have done in 30yrs, you need about 190-200hp to pull a consistent 60mph track speed with a lot of torque to back it up or the engine won't be able to hold that track speed without back shifting, a back shift will decrease the track speed.
 
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maxwell

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I agree 100% with what you say, 60mph (100kph) with 165-70hp is unattainable unless your on less then favorable snow on a climb. Then you might see those numbers but it will not be consistent. The numbers you mention are more realistic to all the custom builds we have done in 30yrs, you need about 190-200hp to pull a consistent 60mph track speed with a lot of torque to back it up or the engine won't be able to hold that track speed without back shifting, a back shift will decrease the track speed.


Thankyou.
 

pfi572

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<<< .That seams to me to be a fair speed for that hp.. They say it's making 170hp, and with skis so far in air, your only utilizing 1/3 of track.. >>>

So you check your track speed with the skis so far in the air your only utilizing 1/3 of track. I think this is where the problem is, people check their track speed different then other people, most of us that have 850T know what the true track speed is, it`s 78 to 80 Klms = about 50 Mph. NA 850 are about 44 Mph,
with about 30 to 35 HP difference.

This ^^^
Track speed is something IMO is a waste of time to talk about on a open forum as most are out to lunch ?
The stock clutching on any doo can be improved upon . Possibly gearing as well .
 

Caper11

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Of course the turbo sled whipped the NA 850, they were at 6500 feet, the turbo had 35 more HP. there is about 5 mph difference between the two sleds,

You are assuming that there is 5mph difference. People are getting bent out of shape over a vid that posted speedo numbers. No one is paying attention to the conditions the sleds were riding in.

The only people that have to buy a clutch kit from some one else are those that don`t know how to clutch their sled. then they say Oh it`s way better. stock sucks, No people that do not know how to clutch their own sled SUCK.
Get rid of the stock secondary setup if you want to see some more gains.
 

1709

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I agree 100% with what you say, 60mph (100kph) with 165-70hp is unattainable unless your on less then favorable snow on a climb. Then you might see those numbers but it will not be consistent. The numbers you mention are more realistic to all the custom builds we have done in 30yrs, you need about 190-200hp to pull a consistent 60mph track speed with a lot of torque to back it up or the engine won't be able to hold that track speed without back shifting, a back shift will decrease the track speed.

Yes you are 100% right, you know how much power it takes to spin a 165 x 16 x 3 inch track at 60 Mph, because you have been doing this for years,
like they say I`am to old of a cat to get screwed by a kitten.
 

maxwell

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You are assuming that there is 5mph difference. People are getting bent out of shape over a vid that posted speedo numbers. No one is paying attention to the conditions the sleds were riding in.


Get rid of the stock secondary setup if you want to see some more gains.


agreed, end of the day, that turbo doo is walking away from that NA sled at a decent rate of speed, quite impressive regardless of numbers
 

Dynamo^Joe

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So you are telling me that a 165 HP sled at 6500 feet is getting 60 MPH track speed, with a 165 x 16 x 3 inch track. BS. now way. you need a lot more HP then that to spin that track at 60 MPH. just all talk. 7900 RPM is 7900 does not matter how you clutch it. clutch kits do not make more power. you can clutch it so it might accelerate faster, but like i said 7900 RPMS is peak HP no matter how you slice it.

Tuning objective
A clutch kit does not make more power. Average Stock clutching is 60~62% efficient. At sea level about 95hp. The tuning objective is to extract more existing power, and bring it to 67~68%, about 10hp increase. Stock converts 95hp, improved clutch settings can convert 105hp. Your objective in clutch tuning is to convert more "existing" hp to the track. Hmm...this is some pretty fancy thing that 105 estimated track hp is fairly constant from sea level to 8000 feet when n/a track hp gets less as elevation increases.

Alleged track speed
It's the last 10% of the season when the snow is packed, wet, heavy underneath. In that video, Pat watched 2 snowfalls before they went out. Its about 1~1.5 ft of snow on top of end-of-season packed snow.

The other 90% of the season, the track speeds are slower because of more depth and best riding snow. Track speeds the guys give me in the totality of the 90% season, I can average out there is 10~11mph increase in track speed at 6500 feet with the turbo over n/a sled.

Down here at 900 ft, the gap's not big enough for me to buy a turbo. The 165 xpert is getting 43mph and Wardo's turbo is getting 46~47.

I did not have to say any track speed in the video. I could have left that out and you still have Chris's sled...in-your-face...right in your "earballs"; running without fluctuating engine speed and track speed you can hear that barely wavers and....but, what's happening?....Pat's sled pulls away, turning into a little "dot" in the distance, going "up" the hill. Who cares what the track speed is then.

I could cross out all what I wrote above and give no proof except make a claim; what happened to Chris, will happen to you.:becky:
 
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fredw

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We are seeing for years with the older Etec 800 turbo track speeds with the 174 tracks.. as a base track speed.. if your only getting 80km/hr now with your new tsled your in trouble.. guys running BB that will work you hard..

Line sleds up on a pull and compare is the best, but once after that you will see hoe efficient your power gets to snow.. joe explains it well, room on the table for much more with that sled
 

oler1234

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Buddy turned into a dot pretty fast, even when the NA sled was track poaching for a bit.


very good example of what the turbo will do for you. Even in the trees you could see the turbo letting of earlier than the NA sled indicating he was not trenching near as long.
 

maxwell

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We are seeing for years with the older Etec 800 turbo track speeds with the 174 tracks.. as a base track speed.. if your only getting 80km/hr now with your new tsled your in trouble.. guys running BB that will work you hard..

Line sleds up on a pull and compare is the best, but once after that you will see hoe efficient your power gets to snow.. joe explains it well, room on the table for much more with that sled

for how long youve been at this game not much you say makes sense. There is no ETEC big bore in existence that will hang with the new 850T at altitude. No Big bore is getting 30-40hp Gain. Not even close. Been there, Played all those games, won ZERO prizes. Switched to what worked. Factory Boost
 

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only watch engine temp and rpm, never watch speed lol. clutch for target rpm and monitor belt heat and read the clutchs.
 

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The ski doo engineers have been testing and working on this 850T for years now, if anyone thinks that those engineers do not know how to clutch their products is fooling themselves, the 850T is clutched for 8000 feet, i ride a little lower then 8000 feet, that`s why my sled was over revving, i added some longer pivot bolts and it now revs 7900 and stays there all day.
and you can feel it pull now. if those track dyno`s were so good how come no one uses them anymore ? the best dyno is a hill. who do you think clutches the ski doo race team sleds ? i can tell you it`s not some guy with a shop in his back yard.
 

1709

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Primary and secondary clutch movements have basically stayed the same over many years. The primary clutch uses arms and a spring inside it while the secondary uses a helix and spring. These are the 4 “basic” tuning parts of the snowmobile CVT (clutch arms, primary spring, secondary spring and helix). The imperfection that all tuners have strived to change in the CVT has been the percentage of slip that is created during the initial start of the shift and during the shifting out of the clutches. Slip is the main inefficiency factor in CVT clutches and belts. This inefficiency also creates heat which is transferred to the belt and clutches. This heat diminishes belt life, and performance. Naturally, the largest changes in clutching technology have focused on correcting these problems throughout the evolution of the CVT. New spring tensions, spring tolerances, adjustable clutch weights and arms, multi angle helixes, improved weight and ramp arch angles, and multiple armed clutches are some of the more notable changes of the last 30 years.

Now my clutches do not get hot, because I have very little belt slip, and if there is very little belt slip putting in another clutch kit will not be more efficient because there is very little belt slip.
if your clutch allows belt slip then yes you can improve the clutching on it.
 
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Lund

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Here is a little food for thought to those who dismiss or maybe skeptical about track speed on a climb. Sleds that make good track speed for their relative class always perform better in all snow condition's and style of riding, including running cooler clutches longer. Efficiency makes track speed, its just that simple, easy to say not easy to do. You can read all the books out there and surf all the forums till the cows come home, nothing beats years of getting your hands dirty and doing it. Every build is another learnt experience, good or bad.
All my builds customers or mine are set up with maximizing track speed in mind for a mountain application. Non of these builds are for below 4500ft and non are for above 8,000ft as it really does not apply for the majority of BC sled areas.
I have posted a build on S&M for the masses to see but I also never reveal everything about the build and this stands true to all my builds I have posted on line such as Doo-Talk a few years back and Totally Yamaha.
I do it only to help people out in sending them in a general direction, its for them to decides what works for them.

As for those who feel when you hear a track humming on a climb it must be fast...LOL...
As for those who try to read their speedo while on a climb...LOL...can't be much of a climb.
Here is a tool to help, especially if you like to do gear changes or driver changes. its called a "SPEEDO-HEALER" Google it, it is used to correct speedometer error. I have been using these since 2010, it will also hold maximum speed that can be recalled after a run.
Here you go that is my secret give away to you for 2020. Maybe now some of you will have legit claims to post.

BTW, BRPs 850 imo is the best 2stroke engine option out there too date that can be use as a base build for a big power turbo(200+). Again that's just an opinion.
 

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The people that do know don`t buy other people`s clutch kits, they clutch their own sled.
 

snopro

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I don't understand why people don't believe a clutch kit can't make a difference? The proof is in the video. Like Joey says who cares about the numbers. The lead sled left the camera sled in its snow dust. I had the opportunity back in the late 2000's to ride new product and became friends with the Doo engineering group. The head of calibration is still a friend of mine. We had some candid comments over some beers one evening. I asked him why the clutching can't be a bit more spot on? We were riding in Colorado at the time at big elevation. He told me their job is to calibrate the sled for a wide range of elevation because that is where the target audience rides, at a wide range of elevation. Can you improve your set up at 7000 ft from the factory clutching? Yes he said but that clutching will not work at 4000 ft or 10,000 ft. In essense there is no spot on clutching available from the factory for one elevation. Its not economically feasible to have 4 or 5 clutch set ups on an assembly line at this point in time. That sadly is how it works and that is why guys like Joey can cash in on the craze.
 
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