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SR Viper, clutching, belts, gearing information


By looking the first post it seams like it.
I'm putting the 8dn belt with the Osp belt adjuster.
 
will these changes also raise the MPG ? if they allow the clutches to shift out more at top end will they also shift up quicker when just cruising at 30-60 thereby lowering RPM and raising MPG ?
 
I will share what I have tested and what I have found using the RTX/LTX models as a testing reference.

1. 8JP belt with stock clutches will be limited to approximately 93-95 mph.

2. 8DN belt with stock clutches will be limited to approximately 103-105 mph.

3. 8DN/8JP belt with secondary setup properly will allow you approximately 113-115 mph.

4. 8DN belt with both primary and secondary setup to match the belt properly will allow you approximately 120-121 mph.

The stock secondary setup with the 8JP belt will stop your belt approximately 3/8" to 1/2" below the top of the primary clutch due to two reasons, the stock secondary will stop shifting at that point and this stops the belt from going any higher in the primary as well.

Now if you install an 8DN belt you can get the belt to approximately 5/16" from the top of the primary and gain some top speed in the correct conditions.

Stock secondary clutch travel is approximately 0.870" and after setting up the secondary properly you can achieve just slightly over 1" of travel (1.008").

Stock primary clutch travel is approximately 1.104" of travel and after setting up the primary properly you can achieve 1.317" of travel and get the belt all the way to the top of the primary clutch, leaving no clutch face surface unused, in the correct conditions.

This is an informational post from Ulmer Racing, call us if you have questions, I do not want to offend or argue with anyone, as it will not help anyone in the end, and there is 100 different ways to alter clutching via the clutch arms, springs, helix, etc, but when the belt is limiting the shift ratio, changing those items will only do so much.

We will offer primary & secondary machining/setup process for those that are interested. You can purchase a clutch kit to match it or if you already have a Ulmer Racing clutch kit I will modify it to work properly as well. If you want to continue to use your own clutching, but want the clutches machined properly with some advice on how to setup your helix/spring I can do that as well.

Phone: 605-387-2833

Email: Srxspec@Gwtc.net

now that we are years past, is all this info still holding true? Have you found better set ups since?
 
So how does this hold up with the Big Venom Kit. I have everything but the Blue secondary spring. I have read that just by using the Kit the viper gets faster speeds because it allows the secondary to open up more with the Blue spring. Is that right and has anyone proven that is true. I have not had any set time on the sled yet to even get a base yet on what it will do. Thanks Rob.
 
So how does this hold up with the Big Venom Kit. I have everything but the Blue secondary spring. I have read that just by using the Kit the viper gets faster speeds because it allows the secondary to open up more with the Blue spring. Is that right and has anyone proven that is true. I have not had any set time on the sled yet to even get a base yet on what it will do. Thanks Rob.
Good question. The guys at Thunder first found the spring binding with stock gearing and held tight for long distance I assume the spring helps correct that issue.
 
So how does this hold up with the Big Venom Kit. I have everything but the Blue secondary spring. I have read that just by using the Kit the viper gets faster speeds because it allows the secondary to open up more with the Blue spring. Is that right and has anyone proven that is true. I have not had any set time on the sled yet to even get a base yet on what it will do. Thanks Rob.

The blue secondary spring is what we have to eliminate the coil bind which allows for more top end.
 
does the secondary clutch have limitations and bottom out? Other Yamaha sleds ive owned we had to machine the helix .08 thousandths. i used to install lead solder in the secondary just to prove bottoming or not. attached is a pic with the solder smashed.




 
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does the secondary clutch have limitations and bottom out? Other Yamaha sleds ive owned we had to machine the helix .08 thousandths. i used to install lead solder in the secondary just to prove bottoming or not. attached is a pic with the solder smashed.




Yes it does unless you gear for what speed you want.
 
I own the RTX LE with 1.7 track. Everyone says this sled does not have very good top end understandably was designed for snowX. How much taller would you guess i could reasonably expect to pull? I did see 82MPH. Once re-geared i can go back to checking for bottoming out secondary. Then adjust weighs to pull correct RPM. Whats your guess as to max gear ratio i could expect to pull?
 
I own the RTX LE with 1.7 track. Everyone says this sled does not have very good top end understandably was designed for snowX. How much taller would you guess i could reasonably expect to pull? I did see 82MPH. Once re-geared i can go back to checking for bottoming out secondary. Then adjust weighs to pull correct RPM. Whats your guess as to max gear ratio i could expect to pull?
Your actually doing well at 82mph.
 
Sled pulls great then just stops pulling. I don't think its HP related when i stop pulling. I get the fact we hit limitations with HP but i don't think HP is my limiting factor at this time.

I'm gunna gear it taller for the start of next season.
I think the gearing is so low that's causing my clutching to bottom out. I see that the secondary spring coil binding is discussed a lot. The blue spring is simple enough if that solves the problem. I nice thing about owning this Viper so many years after its come out.... is that you guys are here sharing your experience. Thanks for sharing.
---mac---
 
On my 800rr that track knocked almost 10mph off the top end. Worth it though! If that holds true a stock Viper with rip 2 is about 90-100mph sled on a good day - 80-90mph with that track. You need more power then gear.
 


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