850 Turbo tunes Reviews

Feb 16, 2021
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You must report back with your findings after a few days of running the tune with Dj's clutching.
I got my first real ride this year in over 2 ft of fresh and a few feet of base on Saturday with a stage 3 bikeman tune with ibackshift clutching. The clutching was phenomenal but the tune makes for a lazy mid-power range. Huge turbo lag on a sled that didn’t have any lag before. When fully boosted its a super fun sled. Seems a lot more like an aftermarket turbo now. I’m thinking about going to a stage 2 for less power drop around 5000 rpm.
 

10003514

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Dec 17, 2007
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it`s not the tune, it`s the clutching that makes it lazy.

It would be interesting to get DJ’s take on this. It’s been mentioned many times the big dip on bikemans dyno runs. Seems to be more prevalent the higher you go with tunes. I sold my Silber turbo to get into a factory turbo as they run just so smooth with an incredible bottom end. I’d like to squeeze a few more hp out of the doo factory turbo but will not sacrifice any response. Stock and a clutch kit is all I’m running this year. I’m guessing we will see a small hp bump from skidoo in the next generation summits.
 

1709

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Feb 14, 2010
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that dip is only on the dyno, Joey from bikeman explained the dip. there is no dip in the real world, quit riding sleds on dynos.
 

irondave86

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Nov 27, 2007
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I have a 21’ with a bikeman stage 3 tune, charge tube, pipe and silencer. It took bikeman awhile to get me the pipe, so I only have a few rides on that setup. I’ll have more data in a month or so.
 

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toms

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that dip is only on the dyno, Joey from bikeman explained the dip. there is no dip in the real world, quit riding sleds on dynos.
Using a chassis dyno for more then 20 years, seeing or looking at a dyno graph with a dip, generally indicated a "miscommunication" between clutches. If you pay attention to where you see the dip on the graph, while out in the field testing, the dip does in fact show up as a hesitation in sled or motor acceleration, especially while putting a load on the motor going up a hill. This hesitation can happen due to secondary not able to keep up with primary upshift input, but can also be due to primary ramp profile, as well as primary ramp weight, and or location of weight, and more. We have found performance gains in gearing changes as well as airbox modifications. This is why you test so many different variables, so you can prove it in the mountains.
Time and time again, we took sleds from the dyno to pro snocross races and successfully puled holeshots . The dyno is a measuring tool, much like a torque wrench. Use it as a tool, you can shorten tuning on the hill by as much as 3 weeks of field testing.
Who wouldn't want to see the results of all of the clutch kits made, on a dyno graph, based off manufacturers best recommendations? How much would that be worth?
 

1709

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On Joey`s dyno there are no clutches, the dyno is on the crank, <<< seeing or looking at a dyno graph with a dip, generally indicated a "miscommunication" between clutches. >>> that dip is easily fixed by clutching. have you ran a bikeman tune ? I have and there is no hesitation or in motor acceleration.
 

1709

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I run my own clutching. it`s a matter of testing to find the right primary spring to get the engagement RPMS where you like it. 3000 rpms it to low in the mountains for my liking, i like 3400 - 3500, i am not a fan of the stock ramps for under 7000 feet. there are a lot better choices out there SHR has some good ramps, as well as others, clutching is an individual choice, depends on the riding you do.
 
Feb 24, 2016
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3000 rpms it to low in the mountains for my liking, i like 3400 - 3500,
My sentiment also, just finished doing some research on available primary springs and installed a new spring to bring my clutch setup back up to my liking. Haven't had a chance to get out and ride yet though to test my math. LOL Running Bikeman stage 2 and aftermarket clutching Frankenstein. I should probably just call it my own clutching at this point.
 

1709

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Feb 14, 2010
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One thing that people can try if they are having problems getting enough ramp weight is to go with the 150 / 250 primary spring.
the lower the second number the lighter the ramp.
 

Thielio20

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Oct 6, 2018
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What I was recommended (for our elevation of 3k-7k) is Stage 1 bikeman, run the stock black spring in the primary and run Joe's kit (which I have). 91 isn't available at the tank around here and those who have been running stage 2+ all mixed racing gas which can get quite spendy and a PITA if you don't bring enough for a long weekend.
 

toms

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On Joey`s dyno there are no clutches, the dyno is on the crank, <<< seeing or looking at a dyno graph with a dip, generally indicated a "miscommunication" between clutches. >>> that dip is easily fixed by clutching. have you ran a bikeman tune ? I have and there is no hesitation or in motor acceleration.
Yes, we have run Bikeman and Silbur both, up to stage 4 for testing purposes in the field. Yes we understand dips in performance can be fixed with clutch tunes. This is why we test with a chassis dyno vs engine dyno. This is also why we make our own clutch parts. Currently in stock turbos we are running close to 105-106 gr. of weight in our clutch kits . We are capable of adding up to 30 additional grams of weight, all underneath the ramp profile Stock ramp profile approx. 96 gr.
 
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