Clutching on the cheap

[Studroes144]

46/50 on a bone stock sled, stamped right in the helix. Pulled 8900-9000 rpm steady no matter how fast u go or how long you hold it, drag/trail setups more the less work in complete opposite of the mountain setups. My MAIN goal is to get my clutches to shift as fast as possible and still maintain peak rpm, mountain setups main goal is to maintain peak rpm by limiting the shift speed. Another factor may be that at 8-10k feet, your vipers are only making 100hp. Here at elevation, I'm making a true 135hp. If a simple 8hp increase of a can can change clutching so much, imagine what difference 30hp would make

 

[shagman]

46/50 on a bone stock sled, stamped right in the helix. Pulled 8900-9000 rpm steady no matter how fast u go or how long you hold it, drag/trail setups more the less work in complete opposite of the mountain setups. My MAIN goal is to get my clutches to shift as fast as possible and still maintain peak rpm, mountain setups main goal is to maintain peak rpm by limiting the shift speed. Another factor may be that at 8-10k feet, your vipers are only making 100hp. Here at elevation, I'm making a true 135hp. If a simple 8hp increase of a can can change clutching so much, imagine what difference 30hp would make

Don't want to argue but one thing is I live and ride in Michigan altitude 700-1500 ft. The reason that I say it won't pull it is that we tried it with several different weights. Great out of the hole but poor top end. Not enough torque and hp to pull that steep. I raced ovals for about 25 years also did testing with Nos and we had the same results with 2 vipers. We tested most of the winter. I put on 2200 mile with lots of different combos and always went back to a 45/39 or 46/40 helix. The stock helix is a straight 43. I am just reporting what was found. I would give yours a try this winter but will have a turbo so no more stock motor testing for me. I will post setup for that after the season starts. Also dyno sheets will be posted when they are done with my sled. The mfg of the turbo kit will post when he is done. He has had my sled since July and will be done shortly. Can't wait for snow. Lol

 

[Studroes144]

Certainly different weights/spring combos will totally change things. It doesn't lack power on top end, actually when I had the quiet can on it was over revving at 104 mph and pinging of the rev limiter on ice, I had to adjust magnet settings to bring the rpm back down, unfortunately I was on a frozen reservoir when that happened and never got the chance to run on ice after that. This setup works for trail riding, it's not ideal, but does the job, I'm fine with that cuz my focus is straight line..which is why we went with the steeper angle to get the best possible setup in a drag race. The sled performs the same whether it's on ice, hard packed snow, or mealy snow, it pulls 8900 rpm everywhere, where it does not perform is in the deep snow when there is excessive track spin, it simply shifts out too fast and doesn't gain back, that's ok tho since I only ever have a 1 mile field ride to get to trails

 

[cannondale27]

My take. Very quickly I knew I was going to need clutching on my Viper. I went with Ulmer because it worked right out of box on my Phazer perfect and I was able to just change rivets for any mod I did on the Phazer. On Viper the Ulmer kit did not work out of the box. I required a very different weight setup then specified and I still wasnt happy. Then the 8DN switch was made and BINGO! Slight weight adjustment and I am happy. Very consistent. Love the easy adjustability. Plan to experiment with different belts and will appreciate the Ulmer kit for the adjustability. I have popped many rivets in stock weights over the years and although cheap it is not going to be done in a field or parking lot.

Now if cheap weights can be found and you want to commit to the 8dn I can tell you all Nos Pros sled is smoother engaging,never hits rev limiter and times and speeds dont lie. I wont admit to his being faster than mine since only time we raced we both wheelied bad and almost hit each other! His setup worked great and I did feel it was smoother than mine.

I think we all agree that after break in SOMETHING needs to be done. All these guys here have made HUGE contributions to all of us helping. Yamaha should be the ones doing it. They didnt so you have choices to make. Thank You guys.

 

[Studroes144]

Don't want to argue but one thing is I live and ride in Michigan altitude 700-1500 ft. The reason that I say it won't pull it is that we tried it with several different weights. Great out of the hole but poor top end. Not enough torque and hp to pull that steep. I raced ovals for about 25 years also did testing with Nos and we had the same results with 2 vipers. We tested most of the winter. I put on 2200 mile with lots of different combos and always went back to a 45/39 or 46/40 helix. The stock helix is a straight 43. I am just reporting what was found. I would give yours a try this winter but will have a turbo so no more stock motor testing for me. I will post setup for that after the season starts. Also dyno sheets will be posted when they are done with my sled. The mfg of the turbo kit will post when he is done. He has had my sled since July and will be done shortly. Can't wait for snow. Lol

Just had to clarify, the numbers are right on the helix just flip flopped, I'm running a 50/46 helix, that should make a little more sense. Too much jazz goin on here I didn't even realize I had my numbers mixed up.

 

[NOS-PRO]

Holy crap! Have I been missing the boat here...... sorry guys.

Trying to catch up here....

Yes, running the 8DN belt needs to have 3 washers added to the tiny 8mm bolts on the backside of the secondary clutch. There are 3 washers (1 on each bolt right now) but will need 3 more (1 each bolt) for the 8DN to be spaced perfectly. Just switching to the 8DN belt will help for those who want to do one thing at a time.

The 3 washers that go under the helix need to be .080" minimum so they can raise the helix enough so the spring does not bind. I have currently machined my secondary to eliminate the need for the washers under the helix.
****Note - the washers can be just regular washers but they need to have 1 side ground to about an 1/8" to fit on the secondary towers. ****

I have the 8FP weights (Thanks for posting guys you guys rock!) setup like I had it you will not only have better engagement, better performance through the whole range but fuel mileage is greatly improved also.

Anyone that needs help with installs of the weights, helix or switching to the 8DN belt, I will be at Wausau grass drags and swap meet this Saturday and don't know how they will be at the gate, but if you want to bring your clutches to me I will switch your parts over for you
If you can't bring your primary clutch in because you don't have a clutch puller....at least I can show you how easy it is to change the weights and spring. Take me about 15 minutes to do both clutches.

Thank you Steve

 

[NOS-PRO]

Nos-pro and stingray, just because a couple guys on here go back and forth with you, keep posting what you clutching is because there are a lot of us that like hearing what you have to say and are learning from your experience.

Thank you weasel33

 

[newtron]

I have 3400 miles on my Turbo viper and lots of trial and error with the clutching. Biggest problem with the turbo is staying off the rev limiter when you take off.
Here is my best clutch setup for great acceleration and top end. I have higher gears as well

8dn belt
24/41 Gears
Supertip weights. (Might try the Dalton weights this year)
Orange Primary spring
46/40 Helix (I've tried 4 different helixes and this had the best results)
Stock secondary spring wrapped at 6 & 2 (Tried 2 other springs but kept going back to the stock spring)

I'm no clutching guru, just posting my best results.

 

[Studroes144]

I have 3400 miles on my Turbo viper and lots of trial and error with the clutching. Biggest problem with the turbo is staying off the rev limiter when you take off.
Here is my best clutch setup for great acceleration and top end. I have higher gears as well.....been a while so will have to search for the actual gearing I have

8dn belt
Supertip weights. (Might try the Dalton weights this year)
Orange Primary spring
46/40 Helix (I've tried 4 different helixes and this had the best results)
Stock secondary spring wrapped at 6 & 2 (Tried 2 other springs but kept going back to the stock spring)

I'm no clutching guru, just posting my best results.

Any idea what the actual weight of your weights are?

 

[newtron]

I just figured out my gearing...24/41. I'll have to do some more digging for the weight of my weights. Man you forget a lot when your off the sled for 6 months

 

[Studroes144]

I just figured out my gearing...24/41. I'll have to do some more digging for the weight of my weights. Man you forget a lot when your off the sled for 6 months

So is that xtx gearing?

 

[newtron]

No I had the xtx gearing until Dave at hurricane was able to make the chain for this gearing. I think xtx is 21/41. With this I would run out of gear around 121 mph. I have had mine up to 125 mph with the 24/41

 

[Studroes144]

Gotcha! So power wise, did your current gearing or the xtx gearing have more mid range pull? It'd make sense the xtx gearing would but certainly not always the case. I'm going to run mine for a bit this winter with stock ltx gearing but the little I've driven it on the grass at only 2.5 psi I can tell it's going to more than likely be very hard to get any type of traction with stock gearing..may have to be toned down a bit and extra top speed is never a bad thing

 

[newtron]

You really don't lose much bottom end with the higher gears. I would say you gain mid range with the higher gears. There is so much power there, going a little higher makes is pull better.

I think LTX gears are the same as the RTX. 24/50. All you have to do is buy a new chain and 41 bottom gear. Pretty cheap top end if your into that kinda thing

 

[Studroes144]

Idk if I'd say I'm crazy about speed, more the less looking for a lightning 1000'-1/4 mile setup. So you just bought the yamaha 41 tooth gear and then a chain from hurricane? Any rough idea on the chain price?