trying to pull more r's m8 slp pipe kit

[mtn mike on boost]

been tuning this sled for awhile and have hit a wall.i cant get it to pull
more than 8080 on a pull.

secondary has the shift assist and rock rollers, stock orange spring and bdx
40/36 helix.

primary i have ran weights from 67gr.-70gr. and springs w/a final rate of
275-340.also using glide washers.

i know i am not far off at 8080, but would like to see how it
preforms w/100-150 more rpm.

i just don't understand how i can drop 3 gr. primary weight and not pull more r's?

 

[geo]

Secondary is controlling the rpm.

Don't know the duration of the 40 part of your Bdx helix, but the Dalton ones are for flat land use (40 part continues for 40% of shift) and I had the same issues with it.

Use a plain old 36 and tune the primary, then try something different on the rear if you feel the need.

Geo

 

[CO_MapMaker]

I am hearing of guys running at 11k and above in the deep stuff having to drop to 65g to get 8200.

 

[racer66c]

Your primary shiv bushing is binding or toast. i just had the same issues on a new 2010 HCR . very odd . new up dated clutch and oh ya she rips. 8150 rpm -8250 rpm 71.5 gr

 

[dfinn]

Your primary shiv bushing is binding or toast. i just had the same issues on a new 2010 HCR . very odd . new up dated clutch and oh ya she rips. 8150 rpm -8250 rpm 71.5 gr

How did you find that out and what's the deal with the "new updated clutch"?

 

[Frostbite]

I am going through similar issues.

First make sure your helix does NOT say 44/36 P. The "P" means it's a progressive helix and you'll probably never hit the 36 degree portion of the helix. You want the 44/36 M. The "M" is for multiangle, which has a much shorter duration 44 degree angle and 90% of the helix angle is 36 degrees.

My sled woke up HUGE when I tried a different secondary spring. The one that fits the nicest is the Fett Brother's Green/white. It will definately wake up your sled and give you a few more RPM up top. I have a Skidoo purple/purple in the there now but, I won't get to try it for a few days.

I noticed the bushing on the primary cover looks ragged as heck. Is that the bushing you are referring to Racer66c?

 

[Desperado]

RPM

I'm in the same boat, I can not seem to pull much over 8k on a pull up hill. I ride 5 to 8k have an 09 m8 162 with slp single setup. I've tried different primary springs different weights in primary, shift assist and no shift assist in secondary, new orange spring in secondary etc. All changes done one at a time to measure results. None and I mean None have gotten me to hold 81 to 82k on a consistant basis. My rider weight with pack and fully geared is about 240. I have not at this point changed my secondary helix from the stock 36. I've tried primary weights from 67g all the way up to 73gs. All cat weights. I still have stock gearing in the sled. I do not understand why I can not get my R's up. My most recent setup 67g primary 120/340 secondary orange with 36deg no shift assist and two black spacers on the outer helix and 1 in the inner. (Stock secondary setup) never saw over 8k and on the lower end it felt like my motor was spooling up good but simply was not pulling hard. Clutch alignment has been checked, I'm at a loss!!!

 

[geo]

I ran the original (07 to 09 pipe) slp set on four 800's and didn't have a problem pulling higher r's ( ride about the same elevation and about the same rider weight as desperado).
My problem was in the hill with the 40/36 and poor backshift. 36 cured that for me, but I run a tortional, so may be comparing apples to oranges.

Back to your issues, could be mechanical. for me 68's would rev to the limiter and not pull any mph on my 07s to 09s.
A few things come to mind ( and there should be something in common here). Some of the common AC things to check: First does it ever rev to 8200 (on the stand, at the parking lot on the hard pack). If it doesn`t then look at engine management (exhaust valves, rare, or fuel pressure way up, more common). Also, check primary rollers or primary cover bushing ( sad to say but I`ve seen lots done in).
One more thing, To have tried 67 gr you may be using after market adjustables. What make and weight range. Some I have found ( because of their initial tip weight bias) make no changes in rpm with weight changes. They just make more heat and less mph.

If everything is good, then I go back to the secondary is controlling your rpm (which is wrong LOL). One of the reasons I use the tortional (which doesnt work for everybody lol), is I had a hard time balancing the clutches with the tortional set-up. Spring and preload were too critical.

Not preaching or selling, just thinking out loud to help maybe.

Geo

 

[Desperado]

I mispoke on the 67g weights, they were acturally 68g. On the stand I can see 8.2k I don't hold it there very long though. My sled only hads 700 or so miles on it. I will check the primary rollers and outer bushing but every time I change weights or spring I give them the quick once over. I'm not familiar with a torchional setup so I do not know how the setups differ. Continue to think out loud, if I did that while trying to figure this out some pretty frustrating words would show up.

 

[mmsports]

Spring

I tried that spring rate would not work. I left weight at stock and put a 42/36 and it will run 8300.



primary i have ran weights from 67gr.-70gr. and springs w/a final rate of
275-340.also using glide washers.

 

[mtn mike on boost]

i cant seem to find my notes i have been keeping, but this will be pretty close to what i have found.

first try slp kit w/ the 40/36 helix orange spring w/ the shift assist and rock rollers.in the primary i tried cutler adjustables 70-80 gr. w/ no added weight and cats titanium version of the orange/white.sled would not pull more than 7700 in the flats ( not enough snow yet to load the sled )

next was the same but w/ 68 gr cat weights.worked good and would pull 7950on a pull, but i wanted a lower engagement and more rpm.( 42 mph on a pull )

next i tried the cat gold w/ 2 glide washers, lowered my engagement but still could not pull over 8000 rpm.( 40 mph on a pull )

next i took a gram out of the 68's, (from the underside of the tips) and didnt gain any rpm.( 42 mph )

now i am running cat 69's w/ a polaris spring 100-340 w/ the glide washers.this is the best by far as far as a low engagement and descent peak rpm.( 44-46 mph now)

i just cant help but think i am fighting the secondary, like geo stated, yet with all the set ups i am reaching full shift out in the primary , and now i am pretty happy w/ the track speeds.just feel they may be a bit more there.
clutches have stayed cool and not gone thru a belt.

by the way the helix is a progressive, they have always worked well for me.
thanks for all the input so far guys

 

[iluv2fly]

I have also tried a lot of different setups and like the heavier primary weights with a heavier finish rate on the primary spring like a 340 rate. I tried lighter weights last year and my sled just lost a lot of pull so I went heavier weights and higher finish rate on primary spring for best results. I also had issues getting the sled to pull over 8000 rpm last year with just the slp pipe but since I have done the porting and the rest of the package it will hit 8200rpm no problem. The porting made more power on mine than the pipe did.

 

[Frostbite]

Mike, I think the below statement may be a HUGE part of your problem.

"by the way the helix is a progressive, they have always worked well for me.
thanks for all the input so far guys".

I have a 42/36 Progressive helix in the BDX box. The reason it's in the box is because I couldn't pull a consistant RPM up top. The shift speed all depended on what angle of the helix I was riding on for each individual climb. It was driving me crazy. One climb I would be at 39 degrees and not be able to pull RPM and then on packed snow it would shift out further to maybe the 37 or 36 portion of the helix and I'd pull more RPM. The was no consistency.

I bet if you try your stock 36 degree helix (consistant angle) you will be amazed at how well it works and how many RPMs you are able to pull.

 

[Bounty Hunter]

RPMs

I am sure that the shift kit takes 150/200 rpms away. We ride at9/11000ft have no problems. I do not use a kit now.

 

[Frostbite]

Wow, I guess I wasn't aware of that fact. What an easy way to gain a couple hundred RPM. What is the downside?


Should I still use the two thick plastic washers in the helix cap? Does removing them affect RPM too?

 

[mtn mike on boost]

just thought i would share a pic. of my 40/36p helix.
i am going to try the straight 36 and see what happens.
i was out ridding concrete snow last weekend and still couldn't pull more than 8070 rpm, so i have to try something

i took a sharpie to show where the roller contact stops.
cant imagine that far up is not back in the 36 degree neighborhood

OK never mind the photo, as i am not allowed to post pics anymore as a FREE MEMBER, but the roller marks stop 3/8" from the top, so i really doubt this is going to help????

 

[mtn mike on boost]

yes, i do realize this thread isnt going anywhere, but just thought i would mention i ran the straight 36 today and i still hit a wall at 8070.

starting to wonder if my stock tach just refuses to read any higher

it is so strange to me that its always maxing out at the same rpm w/ all my changes......

 

[fasta76]

I feel your pain!! I have an 07 M8 and all i can get is 7900rpm! ive done everything like you!! Different weights,springs,helix nothing seems to change it. Im starting to think my primary might just be worn out! Ive been thinking of swaping my gage out with a different one to see if it is my gage.

 

[Flatbed]

I have the same problem. Just bought a 09 M8 sno pro le with the SLP pipe kit. It had 73 weights in primary with the 125-285 titanium spring, 36 helix,. orange spring. 6-9000 feet. won't pull over 7900 even on the stand. Went down to 68 gram with a 120-340 spring. It will hit 8000 on the stand; and that is all. I put it on the hill and my 06 M7 stock will do circles around it. Maybe the 09 M8 doesn't like the SLP pipe. One more thing: The only way I can ride it is in a straight line. It don't turn!!!

 

[mmsports]

Clutching.

Get ride of that spring and it will run. the 125 285 is a better spring try a 142-285

Align you skies. They must be out.

I have the same problem. Just bought a 09 M8 sno pro le with the SLP pipe kit. It had 73 weights in primary with the 125-285 titanium spring, 36 helix,. orange spring. 6-9000 feet. won't pull over 7900 even on the stand. Went down to 68 gram with a 120-340 spring. It will hit 8000 on the stand; and that is all. I put it on the hill and my 06 M7 stock will do circles around it. Maybe the 09 M8 doesn't like the SLP pipe. One more thing: The only way I can ride it is in a straight line. It don't turn!!!