question for those who clutched their D-8's

[AKSNOWRIDER]

I am running 7T 3" pitch avids....

my secondary was pretty warm when i checked it... and i had it on the 60 setting of the helix
Rons weights did help out quite a bit, i was able to hold better rpms with the 1g heavier custom weight over a 10-58.
i kind of wanted to be able to run heavier weights to try to help my shift out as i am still almost an inch away from full shiftout.
When my sled was new Indy Dan balanced and worked over my primary.
How much bigger of a bottom gear can i squeeze in there with my stock chain?

honestly dont know how big a gear will fit..guys last season were running as big as 19/46 so that will fit....with out full shift out ..yea I would gear down..that will bring up the rpm..might also add a couple delrins to the secondary and a fresh spring if it has much time on it(delrins will smooth the shift and fresh springs do make a difference......if you could go up 20 pds on sec spring that would help also.(especially with a hot clutch...)

 

[AKSNOWRIDER]

So, I rode my sled yesterday with the latest flash. Had a pretty good testing ground. (Was the airport runway at west yellowstone) which is about 6700 feet in elevation. I am running SLP blue pink primary, stock secondary, stock helix, and 62 gram stock weights. I was able to pull 8200 rpms consistently with a max at some point of 8300. I know SLP claims 8100-8200 running rpm's for their single pipe set-up, which is what I have. Should I leave well enough alone, or try some different stuff to get to the magical 8350 that some well clutched set-ups are able to achieve. Maybe a different helix? 60-40-.36? Green Pink primary? When Brad rebuilt my primary he tried to use the 68 gram MTX weights, but he said the sled was creeping and he would have to re-shim the spider for clearances. Is it worth it to use the MTX? Seems like when I used them before the sled was less snappy out of the hole, but pulled a little bit harder at full throttle. AK? I know you have some ideas. Gracias.

AEB, was thinking about your setup..the reason the mtx's felt doggy was the primary spring..if you really want to wake it up..have the mechanic reshim for the mtx's, and add the slp green/pink..you will like it.....from what the other guys were running I would try just 1 or 2 grams in the belly and no tip weight....a pain to reshim the primary..but worth it for the feel your looking for....

 

[thefullmonte]

Don't mistake snappiness for belt slip. The MTX or similar style weights won't necessarily feel that snappy, because they are putting the power to the track. A standard 10 series weight will likely slip the belt some upon engagement. Especially on the bigger motors. Your weights with more mass around the pivot will not only engage sooner, but with more force.
The 10 series is a great weight with a nice profile, but with the higher torque motors they lack in side force at engagement and full shift out. JMO
The best thing is to have a buddies sled to run next to yours as a test mule. Swap between the 2 weights if you have them. I think you will be surprised at what a sluggish feeling from the clutch can do.

 

[aebsledder]

AEB, was thinking about your setup..the reason the mtx's felt doggy was the primary spring..if you really want to wake it up..have the mechanic reshim for the mtx's, and add the slp green/pink..you will like it.....from what the other guys were running I would try just 1 or 2 grams in the belly and no tip weight....a pain to reshim the primary..but worth it for the feel your looking for....

I might try that after I ride this weekend. Looks like we are actually going to get some snow, and I want to see how it will perform in normal conditions. I am going to play with it one or two things at a time and see how it goes. Or I may not. A little off topic but I am at a bit of a crossroads in my snowmobiling "career" right now. Contemplating selling it and maybe taking up skiing again. I told a buddy last night that sometimes I feel like I don't have the cajones to get much better at sleddin, and I don't enjoy wrenching enough to get the satisfaction of creating a well tuned machine. Oh well, people have a lot bigger problems in life. Who knows, maybe a good trip with a good running sled will change my mind. Either way, I really appreciate all the great advice you have given me. If I ever win the lotto I would hire you as a "performance consultant" and open a dealership here in Bozeman. I have probably burned 500 bucks worth of fuel just to take it to a dealer who I am not afraid to let work on my sled.

 

[AKSNOWRIDER]

I might try that after I ride this weekend. Looks like we are actually going to get some snow, and I want to see how it will perform in normal conditions. I am going to play with it one or two things at a time and see how it goes. Or I may not. A little off topic but I am at a bit of a crossroads in my snowmobiling "career" right now. Contemplating selling it and maybe taking up skiing again. I told a buddy last night that sometimes I feel like I don't have the cajones to get much better at sleddin, and I don't enjoy wrenching enough to get the satisfaction of creating a well tuned machine. Oh well, people have a lot bigger problems in life. Who knows, maybe a good trip with a good running sled will change my mind. Either way, I really appreciate all the great advice you have given me. If I ever win the lotto I would hire you as a "performance consultant" and open a dealership here in Bozeman. I have probably burned 500 bucks worth of fuel just to take it to a dealer who I am not afraid to let work on my sled.

hang in there...it will rip before to much longer....when it does it will be way more fun then ski's....as for big cajones...not needed..its not about impressing..its about enjoying....a way to forget about life, relax, get some fresh air,exersize, some great veiws, and spend quality time with friends(and family)....I used to ski..after hitting all the local resorts a few times they get boring..sledding..different everytime out....always a new adventure right around the corner....

 

[aebsledder]

Yeah, that was my biggest problem with skiing too. Same scenery, been there done that. I might just be fighting some "no snow" blues too. Who knows? Like I said, maybe a good snow weekend with a good running trouble free vroom vroom will change my perspective. Have a good one and I will be sure to post my result if and when I do some more tweaking.

 

[machinest660]

On my 09 assault i had 68g polaris wieghts, and stock spring and helix and could hit 62mph and 8050 max rpm in 8" of snow. today i put it 62g belly buster weiths a slp blue/pink spring and 3 delrin washers to the seconday. in the same snow conditons i hit 60mph and 8150rpm. all test were done at 2000 feet and setting up for 6-9000. the clutches were warm but could hold hand on either one. i have a black/white spring for the seconday and a 62-42 helix on order. should have this sled not have really reved out with the light wieghts over the 68 gram? should i try the black white spring or leave well enought alone. the rpm would spike to 8300 then drop down to 8150 and hold that the rest of the pull. thanks

 

[MNIQR]

I crunched the numbers and according to them (the numbers) a 19/43 will work with the stock 76 pitch chain. A 46 tooth is the biggest that will fit in the chaincase but the dogleg in a 78 pitch chain will be big.
Also for you guys at sealevel running shorter tracks a 21 tooth on top and the stock 41 bottom also fit with the stock chain.

Heres the numbers if your wondering where i got them from.
2006-2010 rmk chaincase is 8.373 CTC
numbers in () are top gear and bottom gear tooth numbers

8.373*2/.375+(19+43)/2=chain length needed.

so that about formula is for a 19 top and a 43 bottom

which comes out to be 75.656 which is smaller than 76 so a 76 pitch chain will work.
If anyone can confirm that the numbers are correct chime in please

 

[AKSNOWRIDER]

I crunched the numbers and according to them (the numbers) a 19/43 will work with the stock 76 pitch chain. A 46 tooth is the biggest that will fit in the chaincase but the dogleg in a 78 pitch chain will be big.
Also for you guys at sealevel running shorter tracks a 21 tooth on top and the stock 41 bottom also fit with the stock chain.

Heres the numbers if your wondering where i got them from.
2006-2010 rmk chaincase is 8.373 CTC
numbers in () are top gear and bottom gear tooth numbers

8.373*2/.375+(19+43)/2=chain length needed.

so that about formula is for a 19 top and a 43 bottom

which comes out to be 75.656 which is smaller than 76 so a 76 pitch chain will work.
If anyone can confirm that the numbers are correct chime in please

19/43 will work on a stretched chain..but not on a new 76 pitch chain(or so I have been told)

 

[AKSNOWRIDER]

On my 09 assault i had 68g polaris wieghts, and stock spring and helix and could hit 62mph and 8050 max rpm in 8" of snow. today i put it 62g belly buster weiths a slp blue/pink spring and 3 delrin washers to the seconday. in the same snow conditons i hit 60mph and 8150rpm. all test were done at 2000 feet and setting up for 6-9000. the clutches were warm but could hold hand on either one. i have a black/white spring for the seconday and a 62-42 helix on order. should have this sled not have really reved out with the light wieghts over the 68 gram? should i try the black white spring or leave well enought alone. the rpm would spike to 8300 then drop down to 8150 and hold that the rest of the pull. thanks

thats a hard one machinist, if you get too light on weights it wont pull any more rpm because it cant shift out....make sure your springs are fresh for sure(new each season) ..if you go to a 62/42 helix I think you will like the stock black/purple spring more then the black white(but I havent messed with the black white either)....

 

[Vboost]

Has anybody have a good team-tied clutch setp-up yet?

 

[Ron]

Has anybody have a good team-tied clutch setp-up yet?

You might check with Chris at Carl's, they have been testing a # of different setups. As of 2 weeks ago, they couldn't get a "Tied" to perform with A TSS-04. Polaris is likely going with the P-2 next year, 2011 demo sleds will start showing up very soon.

 

[Ron]

I'm going to chime in about Clutching at Altitude.

First, it's unrealistic to expect to get 8300+ RPM at high altitude. SLP and Carl's recommend 8100-8200 for stock/piped sleds. If you can't run 60 grams in the primary you probably won't get full shift, might not get mid shift very well either. (Snow conditions and gearing effect full shift.) Too light of weights and the drive clutch stays in low gear. The higher in altitude-the more this is an issue. There may be a different driven setup that will let you run lighter weights but I don't know of one. Going with more spring in the driven might make things worse, you want the weakest driven spring that eliminates belt slip... the stock Bl/Purple is about right with the 1115 belt. Your 800 at altitude may have less power than a 600 at sea level. So when you read about a good setup like AK's you need to consider air density and altitudes vs your location. Same holds true when you see a good setup running a stiffer driven spring.
Gearing down can help or hurt clutching, IMO. The driven clutch is a torque converter and gearing changes feedback from the track. Shorter and/or lighter tracks have less feedback than heavier/longer tracks. A short track geared too low may reduce feedback to the extent that clutching the primary becomes more difficult.
Altitude also reduces engine compression, the 2010 heads have less compression than the 2008-2009's, so you lose twice.

There seem to be two 800's out there-some sleds run a lot better than the norm and can pull more clutch weight.

 

[rmk727]

Monte , your inputs are always so spot on , but I could not run mtx's in the 727 as the belts slippage was terrible, I've clutched alot of race sleds so know a little, but am still learning about mt set ups. Aks have really helped too. Ron it sounds like you don't like the compression loss in the new head but that is not always a bad thing, it has to go with chamber set up and if a low compression head makes more hp at low alt it then it makes more at high altand the dyno says it makes more with the new head

 

[Ron]

does anyone have a GOOD setup for 8-10000 feet? or even ideas... preferably not running mtx weights.

assault with 153 powerclaw
slp pipe, pcV
19/42
carls helix with stock spring and couple derlins
slp blue/pink primary....i was running some of Ron's weights at 59g, tried 10-58s and wouldnt help, actually worse

it would spike but only hold 8100 or so on a climb
i switched to the shallow angle on the helix and helped a tish bit, but not much. was gonna try a stiffer secondary spring but never had one in the trailer

Cody,

How does your sled pull at 8100, that's not a bad # for 8-10000 feet? 8200 would be better for sure! Some of your issue might be the SLP Blue/Pink Spring. You are running more finish rate with the SLP than the stock Polaris primary spring. If you drop weight, don't shift out and lose performance that's a good indication.

The stock Polaris is 140-330 and adjusting the SLP for the different length of measurement it's about a 140-350.

I might start a thread later this evening but Polaris and Team measure finish rate at 1.19" vs SLP and EPI at 1.25". It doesn't seem like much but a .06" difference in 1.25" is 4.8%. This 4.8% of 200#'s (340-140) is 9.6#'s more finish rate when corrected for the different length. So 140-340 becomes about 140-350 if my math is correct.

So...taking this another step you need more tip weight (that will drop R's) or maybe a little more preload with less finish rate to keep R's up and still get full shift. You might try the Team Red #210135-004...it's a 140-320 or the Team Blue #210135-006...it's a 150-310. I'd lean toward the Blue. I assume you tried stock and didn't like the results!

 

[Ron]

Monte , your inputs are always so spot on , but I could not run mtx's in the 727 as the belts slippage was terrible, I've clutched alot of race sleds so know a little, but am still learning about mt set ups. Aks have really helped too. Ron it sounds like you don't like the compression loss in the new head but that is not always a bad thing, it has to go with chamber set up and if a low compression head makes more hp at low alt it then it makes more at high altand the dyno says it makes more with the new head

True but more compression will give you more snap at lower R's...the more efficient head may produce more power at peak not the entire power band. Compression that is optimum at sea level is not optimum at elevation. Polaris increased head volumn to lower compression-higher compression increases temp and possibility of deto. (2 issues with the 08-09's) The increased efficiency of the design increased power and likely reduced emissions. I ran a milled head from Carl's last year with +15% compression and had no issues so will have my new head milled when I have the time. It's cheap power when it doesn't sacrifice reliability for those of us that will never ride at lower elevations.

 

[robertlaumann]

2008 Iq 800 rpm issues

This may be a little off topic. I have an 2008 iq 800 extended to a 136 with an 1.25 ripsaw. I have only been able to pull about 7900 rpms everything is stock except I have an mbrp can. I would like to get this issue solved by friday so if you could post back thanks. I was thinking about going with 10 66 weights instead of 1068 but im not sure if that would make a difference?

 

[machinest660]

thats a hard one machinist, if you get too light on weights it wont pull any more rpm because it cant shift out....make sure your springs are fresh for sure(new each season) ..if you go to a 62/42 helix I think you will like the stock black/purple spring more then the black white(but I havent messed with the black white either)....

i will check full shift out on wed. marking the primary with a marker. about how much should be left on if it is shifting out fully? i also getting the latest flash done to. my spring should be good there is only 350 miles on the sled. we are going to be in yellowstone riding later this week i will keep you up to date on how this is all working out. AKSNORIDER thanks so much for all the info and useful posts that you have put on this site.

 

[AKSNOWRIDER]

i will check full shift out on wed. marking the primary with a marker. about how much should be left on if it is shifting out fully? i also getting the latest flash done to. my spring should be good there is only 350 miles on the sled. we are going to be in yellowstone riding later this week i will keep you up to date on how this is all working out. AKSNORIDER thanks so much for all the info and useful posts that you have put on this site.

you should get the belt to climb up within about 1/2 in of the top on a steep powder climb..

 

[aebsledder]

Another great set-up by AKSNOWRIDER

Want to say thanks to AK for all his help. Ran my dragon today with a set-up recommended by him and what a difference. Was able to pull 8350-8400rpms at about 6500 feet and 8200 at 9500 feet. Here is what worked for me:
SLP MTX 68 gram weights with no rivets
60-38-.36 Helix
SLP Green Pink primary
Stock secondary with 2 delrin washers
This is with an SLP pipe and can.

Night and day difference.