Thunder Products (Big Venom Viper kit) with Heavy Hitters

[TD Max]

Yup,

If your keeping the 8DN equivalent length....use the 40C4340

If you want to run the 8JP equivalent.....use the 40C4313

These are carbon fiber belts

Curious your thoughts on the reasoning for selecting one versus the other on the Gates? Same compound I assume so dimensions are the only difference?

I guess what I'm wondering is if the 8jp dimensions may be a good thing in terms of shift ratio?

 

[NOS-PRO]

If the belts gates grab harder, I was wondering if I try the gate's 8 JP will gave me more top end. The belt is shorter than 8D and probably force the belt going lowest in the secondary. For sure if the belt going up at the same place in the primary ?

You would think that it would be faster and make the clutching work better, but the 8DN size gave me more mph. Very wierd..... With the EVO flash, I will be trying both belts this season again and different setups to use all of the EVO power and rpms.

 

[NOS-PRO]

This is what happened to the Nytro and Viper of mine while testing.... Since the hub-bub of the 8DN belt working better on the Viper instead of the 8JP, I took the belt off of my Nytro 1 day to see. My oldest son who was riding the Nytro was not happy because I took his 8DN belt.....so I told him to put the 8JP belt on the Nytro. 2 different center to centers and switching the belts between the 2 sleds made both of them faster. Yeah....mindblown

 

[murdered141]

What are the torque spec's on the weight bolt's and Allen screw's, and do the require thread locker?

 

[rbell14]

Here is the data that was once posted that I saved.

2015 Viper Clutch Torque Specs


Primary Clutch Bolt: 85 Ft-Lbs to seat clutch then tighten primary clutch bolt to 43 Ft-Lbs. (Bolt wet with a little engine oil.)
Secondary Clutch Bolt: 46 Ft-Lbs

Primary clutch cover 10 ft/lbs (6 - bolts)

Roller and weight nut 4.3 ft/lbs

Secondary width adjustment bolts 5.1 ft/lbs (backside of clutch)
Secondary helix locknuts 17 ft/lbs

 

[murdered141]

Here is the data that was once posted that I saved.

2015 Viper Clutch Torque Specs


Primary Clutch Bolt: 85 Ft-Lbs to seat clutch then tighten primary clutch bolt to 43 Ft-Lbs. (Bolt wet with a little engine oil.)
Secondary Clutch Bolt: 46 Ft-Lbs

Primary clutch cover 10 ft/lbs (6 - bolts)

Roller and weight nut 4.3 ft/lbs

Secondary width adjustment bolts 5.1 ft/lbs (backside of clutch)
Secondary helix locknuts 17 ft/lbs

I got all that, I am talking about the weight's that fine tune clutch.

 

[shagman]

I got all that, I am talking about the weight's that fine tune clutch.

Snug with thread locker supplied. Or blue loctite.


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[chaleurphantom]

"Take 4"

After adding one more .4g washer to the middle hole, RPM dropped to 8800-8900 at WOT at 95 MPH consistently. However, still hitting the rev limiter hard from a launch until 30 - 40. Yes, I am spinning the track on hard packed snow. Ski's in the air and cutting a nice even launch trench until I get to mid range and the front end settles down a bit. Tonight I will add a 1/4" set screw in the heel to control RPM at launch and see what that does during tomorrows test rip. Will also remove one of the 2 thin washers from the middle if adding heel weight doesn't affect the top end RPM. Still wrapped at 6-1 on the secondary, and will go to 3-3 if heel weight doesn't resolve the launch control.

Shagman and I talked about the weight transfer differences between the LTX and the XTX as primary contributors to the over rev at launch. being uncoupled, the XTX can transfer weight deeper than LTX because of limits of our coupling. Once my ski's come up (a lot higher than they used too due to the added traction of the 1.6 cobra), I am sure that the front of the skid is getting light and that is causing some of the track spin.

"Take 4" set-up:
8DN
blue-silver-blue primary spring with glide washer each side
3/4" set screw heel
3/8" head aluminum and (2) thin washers in middle
7/16" head steel in the tip
6-1 secondary wrap with TP Big Venom blue spring

So where are you at now?

2016 Viper XTX LE I have also installed the Big Venom kit with the Sandale exhaust. I have installed the Gates carbon belt as well. I am also hitting the Rev- limiter on launch until 30ish MPH. Goes like the devil though. I haven't had the chance to test on the trail yet, just a quick field testing. I do not like to bang off of the rev-limiter on take off though.

 

[shagman]

So where are you at now?

2016 Viper XTX LE I have also installed the Big Venom kit with the Sandale exhaust. I have installed the Gates carbon belt as well. I am also hitting the Rev- limiter on launch until 30ish MPH. Goes like the devil though. I haven't had the chance to test on the trail yet, just a quick field testing. I do not like to bang off of the rev-limiter on take off though.

SnoNinja ran out of snow. Lol. Got warm and rain. Make sure your clutches are warm before you make power runs as the gates belt will slip a little but it has more grip when up to temperature. Are you hitting the limiter once or multiple times. If hitting only once put some miles on for things to break in. You can also go to a 3-3 wrap on the secondary and try it. If hitting multiple times add a thin washer to middle bolt on weights. Keep us posted.


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[chaleurphantom]

I am hitting multiple times. I was thinking the same thing about the middle washer. I have a slight belt squeal in the primary as well. Just at idle. This may take care of itself after break in of the new belt.

 

[shagman]

I am hitting multiple times. I was thinking the same thing about the middle washer. I have a slight belt squeal in the primary as well. Just at idle. This may take care of itself after break in of the new belt.

Go to 3-3 wrap on secondary also. Squeal might be deflection a little tight. See if that breaks in. It might do that cold but should go away when warm.


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[SnoNinja]

So where are you at now?

2016 Viper XTX LE I have also installed the Big Venom kit with the Sandale exhaust. I have installed the Gates carbon belt as well. I am also hitting the Rev- limiter on launch until 30ish MPH. Goes like the devil though. I haven't had the chance to test on the trail yet, just a quick field testing. I do not like to bang off of the rev-limiter on take off though.

Simple question, not so short of an answer.

I was able to cure much of the rev limiter problem at launch with a 3-3 wrap, I didn't mess much with weight after that as I got thin on snow. I do know that at 3-3 I was too heavy on the weights even though I pulled the same top speed. Still hitting the rev limiter at launch, but only once now. 3-3 will let the secondary shift quicker at launch dropping your rpm and keeping you off the rev limiter. Back shift won't be quite as good as 6-1 wrap. I even ran it at 6-2 wrap and the mid and upper pull was great, but couldn't control the launch. With the LTX coupled suspension, there seems there are limits to the amount of power you can put to the ground and still control it. I am running a 1.6 cobra which hooks up much better than the 1.25 track. On take off, there is less track spin resulting in more load on the secondary which prevents the secondary from shifting. Delay the shift and rpms build too quickly resulting in multiple hits on the rev limiter until you are out to 30-40 mph. This is also compounded by the wheelie that the deep lug track causes on the 137" coupled skid. The added traction results in a wheelie that unloads the front of the track and results in a instantaneous track spin that puts you into the rev limiter. The condition is more manageable in looser snow as the track spins from launch allowing the upshift to start before you get in the rev limiter. Controlling rpms at launch by wrapping 3-3 helped, but the sled was more lively with a tighter wrap on the secondary.

Right now I am experimenting with the stock pink secondary spring (my secondary is machined to eliminate coil bind with the stock pink spring), and will also be testing with other primary springs and helix angles until I get the desired out come.

We haven't heard of too many guys with the RTXs, LTXs with the 1.25 track, or even the XTX guys having similar problems. It seems to be limited to those of us with the 137" deep lug track (1.6 cobra, 1.6 ice cobra, and 1.75 back country).

NosPro was really happy with his clutching set up at 6-1 wrap last year on his XTX. His weight set up was different than mine as our sleds act differently due to the rear skid (uncoupled XTX vs coupled LTX). On your sled, I'd try to stay at 6-1 and add weight where you need to to get the rpms down if you can. NosPro and Shagman can offer better advice there than I can as they have much more test time on the kit.

Was trying to limit my testing to working just with the weights and spring from the BV kit, but to satisfy my personal performance requirements, I might need to stray from the components in the BV kit in order to get the clutching to perform the best from launch to top end. My personal preference for my riding style is hard pull mid and top with fast back shift for corner to corner acceleration. With the built in rev limiter, this causes problems because I have to limit rpm at launch, and the aggressive clutching up top is not conducive to less aggressive clutching at launch given our stock helix and primary spring.

Everyone's prefered set up will vary, and that is the beauty of the BV kit or any other kit with adjustable weights. We can tune to suit our individual preferences.

Will be testing more this week at Munising next weekend with Shagman. Should have it sorted out by then and will post my set up once I get to something that I think is the best we can get without having to raise the rev limiter.

 

[Janne339]

Anyone tried the 14,8 mm rollers yet? 14,8 mm rollers and remove washer from tip. Faster upshift at launch without hitting rev limiter?

 

[chaleurphantom]

Simple question, not so short of an answer.

I was able to cure much of the rev limiter problem at launch with a 3-3 wrap, I didn't mess much with weight after that as I got thin on snow. I do know that at 3-3 I was too heavy on the weights even though I pulled the same top speed. Still hitting the rev limiter at launch, but only once now. 3-3 will let the secondary shift quicker at launch dropping your rpm and keeping you off the rev limiter. Back shift won't be quite as good as 6-1 wrap. I even ran it at 6-2 wrap and the mid and upper pull was great, but couldn't control the launch. With the LTX coupled suspension, there seems there are limits to the amount of power you can put to the ground and still control it. I am running a 1.6 cobra which hooks up much better than the 1.25 track. On take off, there is less track spin resulting in more load on the secondary which prevents the secondary from shifting. Delay the shift and rpms build too quickly resulting in multiple hits on the rev limiter until you are out to 30-40 mph. This is also compounded by the wheelie that the deep lug track causes on the 137" coupled skid. The added traction results in a wheelie that unloads the front of the track and results in a instantaneous track spin that puts you into the rev limiter. The condition is more manageable in looser snow as the track spins from launch allowing the upshift to start before you get in the rev limiter. Controlling rpms at launch by wrapping 3-3 helped, but the sled was more lively with a tighter wrap on the secondary.

Right now I am experimenting with the stock pink secondary spring (my secondary is machined to eliminate coil bind with the stock pink spring), and will also be testing with other primary springs and helix angles until I get the desired out come.

We haven't heard of too many guys with the RTXs, LTXs with the 1.25 track, or even the XTX guys having similar problems. It seems to be limited to those of us with the 137" deep lug track (1.6 cobra, 1.6 ice cobra, and 1.75 back country).

NosPro was really happy with his clutching set up at 6-1 wrap last year on his XTX. His weight set up was different than mine as our sleds act differently due to the rear skid (uncoupled XTX vs coupled LTX). On your sled, I'd try to stay at 6-1 and add weight where you need to to get the rpms down if you can. NosPro and Shagman can offer better advice there than I can as they have much more test time on the kit.

Was trying to limit my testing to working just with the weights and spring from the BV kit, but to satisfy my personal performance requirements, I might need to stray from the components in the BV kit in order to get the clutching to perform the best from launch to top end. My personal preference for my riding style is hard pull mid and top with fast back shift for corner to corner acceleration. With the built in rev limiter, this causes problems because I have to limit rpm at launch, and the aggressive clutching up top is not conducive to less aggressive clutching at launch given our stock helix and primary spring.

Everyone's prefered set up will vary, and that is the beauty of the BV kit or any other kit with adjustable weights. We can tune to suit our individual preferences.

Will be testing more this week at Munising next weekend with Shagman. Should have it sorted out by then and will post my set up once I get to something that I think is the best we can get without having to raise the rev limiter.

Awesome info. I think I will stick with 6-1 for now. I am going to try some mid-weight and see where that goes. I will try to contact NosPro and see what he thinks.

We are going to be limited with snow here as well. We only have about a foot where we should have about five feet by now. Rain on the way for monday as well.

Thanks for your info.

 

[murdered141]

Can't have my favorite thread on page 2