Where to start with clutching a SC Nytro?

[snowy1]

the dalton green is 57/129 so it will have alittle higher engagement, the p-s-p is 35/134, I don,t think you need the higher engagement with the SC.

 

[spray25]

Yeah that would raise the engagement to much. I am going ot try the O-P-O and moving weight from teh mid to the heal.

 

[TurboJamie]

the dalton green is 57/129 so it will have alittle higher engagement, the p-s-p is 35/134, I don,t think you need the higher engagement with the SC.

I belive the datlon is measured at a different height though then the yamaha springs.

 

[rxrider]

The larger rollers will not keep the weights from raching the tip, but they slow down the upshift because they transfer less clamping force to the primary movable sheave. The smaller rollers will put more force on the belt at all ratios, bottom to top end.

Were you down on rpms on the big end as well?

Taking off the weight from the mid will raise top end rpms slightly.

Not sure what you mean by "big end", but when I accelerate at full throttle I quickly go to 9000 rpm then as I continue to travel it falls to around 8200. That is with:

16.5 rollers
7.6 G heal
7.6 G mid
0 tip
P-S-P
Pink secondary at 70
Shockwave at aproximately 45

What are the down falls to the dalton green spring? what is the engagement like?

What I meat to ask was, what is your rpms at top speed. The mid weight you have in there will influence your rpms at midrange speeds. Dalton green spring will give you a engagement speed of 4500 approx. I run the Dalton Green primary in my turbo with the STs loaded 7.4 heel, 7.4 mid, 2.5 tip for a total of 77.7 Grams.

I think you will get close with changing a little on what you have, more in the heel, less in the mid, adjust tip for the top speed if needed. Rule of thumb when you add/remove weight: 1 grams change (at each weight arm) nets a 100 rpm +/- change.

 

[BlgsRX-1mtn]

Ray; are you running what MPI sugested for a starting point? For what it's worth, I did and here's the results;

My engagement is ~2800-3000 RPMs. The engine will over rev on hard pack and I see ~9800 climbing. MPI's settings were close enough for me to keep that setup. My shockwave is on it's way so hopefully that will cure the over rev on the trail and allow me to keep the RPMs while climbing.

MPI's suggestion on my Stage 1 on the RX-1;

Use the stock '03 primary spring with the stock 8FA-00 weights loaded up in the heal and tip (69.43 gram weights with 4.5 gr in heal and tips). 14.5mm rollers.

The secondary has the stock helix with the pink spring at 70 degrees twist.

Jim

 

[HYFLYR]

I dont have a nytro but on my boosted apex i like running my secondary at around 90, this kept top end in check and was easy on the backshifting as well. Sounds like you are headed in the right direction though, and there is some good info on here as well. I would take it to the hill or get it out now, then adjust from there. My first ride was in minimall snow conditions and street riding and was close to where i wanted it but when i got to the hills and playing in my normal areas it was off quite a bit from where i thought i should have been. Just my .02. Good luck

 

[spray25]

Jim,

I have not tried MPI's recomended clutching. They are using the stock weights. I would prefer to try the supertips for now. IF they don't work though I will look closer at their setup.

 

[snowy1]

The supertips with work better than stock wieghts once you get them dialed in, I still think the 14.5 rollers would help as will, they work good with the supertips, I would wrap the secondary tighter too as was already suggested, 90-100,

 

[HAMMER]

If it were my sled I would try this: 14.5 rollers, White secondary spring at 70-80 pre-load, 45* on the adjustable helix setting, heal loaded and adjust mid-tip weight as needed.

You mainly ride from 5500 (Brundage) to 8500 (Granite Mtn) so you can let it be a tad high at 5500ft, you want it dead-on at 7000ft, and a tad low at 8500ft. I haven't seen a Stage-II SCNytro dyno but Allen Ulmer told me on the stock runs he did peak power was around 8500-8600-8700 .

 

[spray25]

Thanks Hammer. I have a white secondary spring on the shelf so I will try that. I have to order the rollers as Hinson's doesn't have any. When you say "heal loaded" what are you thinking for a starting point as far as weight?

 

[HAMMER]

With the 60g base weights, Tungstens in the heal will put you at 75g, three 1-gram washers each side, o-rings, screws, in the mid will put you around 80.3g total, leave the tip empty. The smaller rollers with that O-P-O (30-137) may cure the over-rev off the bottom.

Oh ya, if you haven't already, scrub that belt, and clean the clutch faces.

 

[spray25]

I am running the straight rate Shockwave. Should I be running the multi angle? On tubos they dont usually hav ethe low end to pull the multi angle, but with the SC I have plenty of low end.

Wouldn't that also help the over-rev on take off? Hammer what helix are you running?

 

[snowy1]

I would run a straight helix in the mountains, a multi works good for trail riding and drag racing but I have found the straight works better in the mountains, 45 degree works good up to 12-14 lbs after that 47 degree, some use a 51 but I never could get it to work like the 47, this is with a turbo but I think thhe SC will be similiar.

 

[HAMMER]

Hammer what helix are you running?

Here's the short version. Started out with a straight 48 and a bunch of weight/spring combo's. Then went to a straight 52 and a bunch of weight/spring combo's. Then went back to the straight 48, a bunch of weight/spring combo's, and Supertips. Still not what I wanted. So went to a 58/42 full progressive and a bunch of different weight/spring combo's. Still not what I wanted. So I went with a 56/46 full progressive, 140-240 TEAM spring in the secondary, Supertips, with a polaris 100-275 spring in the P85 primary. This was close but still not what I wanted. Finally I went with a 56/44 full progressive, 160-260 TEAM spring in the secondary, Supertips, with a polaris 70-290 spring in the P85 primary. This is where I'm at now and I'm sure I'll change it again depending on how the nitrous affects my setup this season. Looking at buying a 54/42-54/40 full progressive to experiment with also. Total parts experimented with so far: 5-sets of weights (finally bought the Supertips), 7-primary springs, 6-secondary springs, 4-helixes (the TEAM helix has two different cuts per helix so thats 8 different cuts).

 

[lakercr]

Hammer what helix are you running?

Here's the short version. Started out with a straight 48 and a bunch of weight/spring combo's. Then went to a straight 52 and a bunch of weight/spring combo's. Then went back to the straight 48, a bunch of weight/spring combo's, and Supertips. Still not what I wanted. So went to a 58/42 full progressive and a bunch of different weight/spring combo's. Still not what I wanted. So I went with a 56/46 full progressive, 140-240 TEAM spring in the secondary, Supertips, with a polaris 100-275 spring in the P85 primary. This was close but still not what I wanted. Finally I went with a 56/44 full progressive, 160-260 TEAM spring in the secondary, Supertips, with a polaris 70-290 spring in the P85 primary. This is where I'm at now and I'm sure I'll change it again depending on how the nitrous affects my setup this season. Looking at a 54/42-54/40 full progressive to experiment with also. Total parts experimented with so far: 5-sets of weights (finally bought the Supertips), 7-primary springs, 6-secondary springs, 4-helixes (the TEAM helix has two different cuts per helix so thats 8 different cuts).

Yes, but what else have you tried...