Viper Clutching Confusion

[bigreis]

144 track cut to 1.25 is plenty of traction...

My point about messing up the traction is that there are "tread" patterns on the lugs tracks for a reason... if all it took was flat rubber nubs (which is what he will end up with if he just clips the lugs off) to get good results, then why would everyone complain about the stock viper tracks?

 

[tomseal6]

I can understand your theory up to a certain point.

I had a 2007 Mountain Apex with a 162 inch track with the lugs cut down to 1 inch.. Almost nothing would touch it in 500 feet. I got 116 MPH out of it on the speedometer with Attack clutching and gearing.

With all the extra track and extra weight from a long track its not goinf to matter

 

[mod-it]

So I don't want to get up over 88 or 8900 RPM? I read in the HeelClicker instructions that they suggest RPM's of 8400 for the Viper and SRX. In another part of the instructions is says "moving" weight to the tip will help increase top end speed. I also have heard the adding 1g = 100 RPM drop. So 1g per weight would drop the RPM's by 300. So I need to take off my primary again and add more weight. But not sure if I need to add any to the center or keep adding to just the tip.

As far as your RPM's go...

STOCK SINGLE PIPE rpms were 8400-8500...which is what the heelclicker instructions are referring to, but you have SLP pipes. They make peak hp at 8900 rpm, so that is your target.

 

[Super Sled]

As far as your RPM's go...

STOCK SINGLE PIPE rpms were 8400-8500...which is what the heelclicker instructions are referring to, but you have SLP pipes. They make peak hp at 8900 rpm, so that is your target.

For what it's worth, listen to Mod-it and take his advice, as he really knows his stuff about clutch tuning for elevation and esp in regards to using aftermarket/ SLP pipes......

 

[dcfjef]

tomseal6: You are right I have 8T drivers. They are anti-ratchet drivers (didn't even know they were on this sled.

I changed my Heelclicker clutch weights and went down to 3.3g in the shoulder, put 3.3g in the center hole, and 3.3g in the tip. This is the suggested weight in the H/C booklet when running a 46/36 secondary helix. I was previously using the piped suggestion. This run was 95.0mph on GPS and 8900-9000 RPM. It was so rough I wasn't able to get a good look at the RPM.

Found out I have another problem. The snow is so hard packed here in ND it is like ice, so I am able to get the good fast runs. However when I hit a bump and spin the track, I am losing lugs off of my 2" track.

So now I am in search of a good 144" track. I see a lot of posts suggesting ripsaw and others suggest a cobra. Is a 1.25" sufficient grip when riding in stubble fields and road ditches? Or would a 1.5" be that much better? Since I am going from a 2" down to 1.5" I assume I would even see an increase in top end speed perhaps?

 

[tomseal6]

144 track 1.25 lug is more then enough.

Your going to be busting lugs left and right doing high speed runs on the ice or hard pack with 2 inch lugs. The lugs on the outside will go first as they are smaller and easier to break off.

with a gearing change, you should be well over 100, just play with the clutches again.

a set of 5.35 wheels in place of the stock 5.125 will also help wherever you can put them.

 

[dcfjef]

I forgot to add that you probably have 8 tooth drivers with the 2 inch lug,

In order to correct the ratio for the smaller diameter drivers, (If I am correct on you having 8 tooth drivers) I would go to a 24/38 ratio since top end is what you looking for.

You will have to play with the clutches again to get the RPM's right for doing the gear change.

I do have the 8T drivers, but if I currently have stock gearing (38/22) won't I lose top end if I switch the top gear to a 24T from a 22T?

 

[tomseal6]

No you will gain top end but give up some bottom end. If your goal is more top end, it doesnt matter.

24/38 will correct the gear ratio back to stock with 8 tooth drivers.

The gear change will be much easier then changing drivers back to 9 tooth with a 1.25 track.

 

[bigreis]

Going to a 24T top with 8 tooth drivers will bring you back to stock short track gearing, but I don't think that is where you are going to want to be from my experience. With a 144" track, you have a lot more mass and resistance that the engine is trying to turn, so you are going to need to "reduce" this extra load the clutches and engine are seeing by going to a slightly different gear ratio. If you make the top gear smaller, it makes it easier for the clutches and engine to turn the track, but will also reduce your top speed slightly with everything else being equal. So instead of going to the 24T top, maybe do a 23T. I just went down a tooth from stock gearing in my 136" but haven't had time to test it out yet... hopefully after this weekend I will be able to have some info to report back.

 

[tomseal6]

He has heel clickers that are very adjustable.

You can easily adjust the clutches for a gear change

 

[bigreis]

I agree with that up to a certain point. But, if adjusting the clutch weights was the cure for every situation, why would we ever have to worry about gears, helix angles and springs?

My understanding is that a properly setup CVT transmission is designed to operate EFFICIENTLY within a specific load and power range. With a longer track you certainly have changed the load. The only way to reduce that load is to change the gearing. If you look at the setup of the Mountain Viper, you will find that the gearing, springs and weights are different than the standard Viper. The only difference in these two sleds (in the power train anyway) is a longer, heavier track.

Again, I am not an expert by any stretch and could be way off in my logic, but I really want to learn more and try my best at sharing the information that I have recieved from others. It is great having a place like this to learn more about our sleds!

 

[tomseal6]

And I agree with you up to a certain point,

However, the guy is trying to get more top end out of his sled. There is enough adjustment in those clutches to run 2 more teeth on top and still have it perform ok on bottom end.

On his SLP PIPED VIPER, there is no way you are convincing me that his motor would struggle to turn a 144 1.25 track on top with equal to stock gearing.

 

[bigreis]

Well, on my SLP piped Viper the guys from SLP specifically told me that I needed to drop a tooth on the top to get it to work properly simply because I am running a 136" 1.25 track. Now I haven't had a chance to test out the new gearing yet, so like I said earlier, I am only passing on information that has been provided to me by other experts (if we consider the guys at SLP to be experts).

 

[mrviper700]

I am not a clutch tuner by any stretch. But am trying to maximize my top speed on my Viper with 144 track extension. I don't drag race at all, just a ditch banger and farm field rider. But I don't like to get beat if we have a long stretch where we can open them up.

My setup: SLP Pipes, HeelClicker weights, Red H/C primary spring, Dalton 46/36 Helix, Green Yamaha secondary spring.

We have had 45 F temps for a week so the snow melted and compacted a lot. Now it had been 5-9 F the last 2 days. So I made a couple trial runs.

4.8g shoulder weight, 0 center, 3.3g tip, H/C red primary spring, 51/43 Yamaha Helix wrapped at 60, pink secondary spring = 9000 RPM and GPS speed of 98.6 and the belt was fairly hot.

4.8g shoulder weight, 0 center, 3.3g tip, H/C red spring, 46/36 Dalton Helix wrapped at 70, green secondary spring = 9000 RPM and GPS speed of 95.9 and belt was just warm to the touch. Felt real good but not sure why I lost almost 3 MPH. Outside temp 9 deg. F.

Added 1g weight to each tip. 4.8g shoulder weight, 0 center, 4.3g tip, H/C red spring, 46/36 Dalton Helix at 70 wrap, green secondary spring = 9100 RPM and GPS speed of 92.5. I am running on the same 1/2 mile stretch of ditch and the snow is as hard as ice, so I believe the conditions are the same. Outside temp 4 deg. F.

What am I doing wrong to try and get more speed?

I dont think your using enough weight in the tip with the 46/36, try something more like 4-5 grams heel weight, 3.3 center and 4.3 tip, red primary spring and the stock red secondary yamaha spring at 90 degrees.

in your above test you used a stiffer sec spring on a smaller helix, the red stock sec spring works quite well with the 46/36

as far as gearing goes, your likely to need a bit more with a larger lug and longer track... the steeper gearing will simply make the sled pull more clutch weight, so be it, if all your looking for is say 95mph tops the steeper gear will get you there quicker.

 

[tomseal6]

Well, on my SLP piped Viper the guys from SLP specifically told me that I needed to drop a tooth on the top to get it to work properly simply because I am running a 136" 1.25 track. Now I haven't had a chance to test out the new gearing yet, so like I said earlier, I am only passing on information that has been provided to me by other experts (if we consider the guys at SLP to be experts).

I agree and I think the experts are correct. On a 121 viper with 9 tooth drivers with SLP pipes, going up 1 tooth to a 23/38 would be the same gear ratio of a stock SRX and both sleds have similar HP with the viper having SLP's

My point is if I wanted to run my buddies off the road or blow by them on a 144 track like the original poster does, I would run those gears and tune the clutches for it, especially if I had heel clickers to play with.

The good thing about having a long track and taller gears means your not going to spin out all that much from a hole shot.

Keeping steep gears in it and loading the weights will get you there much quicker but I couldnt handle having a 600 pass me by at 90 MPH or so.

 

[dcfjef]

I dont think your using enough weight in the tip with the 46/36, try something more like 4-5 grams heel weight, 3.3 center and 4.3 tip, red primary spring and the stock red secondary yamaha spring at 90 degrees.

in your above test you used a stiffer sec spring on a smaller helix, the red stock sec spring works quite well with the 46/36

as far as gearing goes, your likely to need a bit more with a larger lug and longer track... the steeper gearing will simply make the sled pull more clutch weight, so be it, if all your looking for is say 95mph tops the steeper gear will get you there quicker.

Hey MrViper, welcome back. Hope all is well with you.

I do want to try your setup. I was working my way up to different weight combos. However, I was afraid to add too much weight since I am in the 8900 RPM range now.

I was only using the secondary springs that I have on hand. I have a green from the Viper and have a spare pink from an RX clutch. So I was using the weakest secondary spring I have available with the 46/36 and using the stiffer pink with the 51-43 (this helix is also from the spare RX secondary).

I need to see if I can find a cheap red secondary and give your suggestion a try.

Thanks for the info and take care of yourself.

 

[bajardine]

Well, on my SLP piped Viper the guys from SLP specifically told me that I needed to drop a tooth on the top to get it to work properly simply because I am running a 136" 1.25 track. Now I haven't had a chance to test out the new gearing yet, so like I said earlier, I am only passing on information that has been provided to me by other experts (if we consider the guys at SLP to be experts).

In my experience, the longer heavier track with taller lugs is not the only reason to gear down. I learned the hard way. I bought a MM700 with 136" track and shortly after bought a set of SLP triple pipes to put on it. I did everything from the clutching to switching out the needle jets, etc. Everything that was recommended by SLP except I used a little more tip weight. I did not however change my gearing. The sled pulled just fine. The clutching was right on and I held 8900 RPMs climbing anything. I didn't think the gearing would make any difference. I did go through a lot of belts though. It seemed like every 3-4 trips I would blow a belt. I figured my clutches were out of alignment. They had to be. What other reason was there for breaking my belts. I bought some clutch alignment tools and was shocked when everything checked out fine. Finally I bought the top gear SLP recommended and I haven't lost a belt since. I've had the same belt on the sled for about four years now. I had figured that the reason for the gear change was just the elevation I was riding at but that isn't all. Just the other night I was reading in Aaen's clutch tuning manual and it says "if the engine speed has been increased from 8000 to 9000, the machine is automatically geared 11% higher". If you do the math, it works out. If you look at the instructions for the SLP 700 triple pipes, if riding at 0-5000ft, it says to drop a tooth on the top gear. If riding above 5000ft, drop two teeth. This is before even considering a longer track. I sure wished I'd have got that new gear from the start. At $60+ for a new belt, they sure add up quick.