Thunder products

[ricer68]

I’m going through my clutches on 14 xtx. It has a thunder products heavy hitter kit in it. Does anyone know what the spring rate is on their blue secondary spring? I called them and they don’t know......

 

[ricer68]

Also what twist should I be using? I’m new to clutching. Currently has a stock helix, will be going to a reverse helix shortly just trying to get everything else working right. I’m not getting all my RPMs on a wot run. Only getting 8100 range. I’m putting a stiffer spring in the primary, currently a blue silver blue.

 

[SnoNinja]

Also what twist should I be using? I’m new to clutching. Currently has a stock helix, will be going to a reverse helix shortly just trying to get everything else working right. I’m not getting all my RPMs on a wot run. Only getting 8100 range. I’m putting a stiffer spring in the primary, currently a blue silver blue.

PM NosPro or Shagman. They are TP vendors and will help you with anything you need.

 

[PeeWee86]

Is knowing the rate of the blue spring all that important? The factory pink spring has been successfully used by many. It is tried and true. I would ask Thunder Products how the two springs differ and how their blue spring improves upon the factory pink spring. Even if they don’t know the rate of the blue spring they should be able to answer these other questions. If you do ask them these questions please post their response.

I am a believer in choosing a cam angle(s) based on torque sensing needs (stronger up shift or back shift) and load first, and then tuning the primary clutch for target rpm. If you already plan on changing the cam I would do that first before I spent too much time finding your target rpm with your existing cam. With that being said, I did look at the Yamaha spring chart and I agree that your existing blue-silver-blue is probably two weak for optimal performance. I would try a green or possibly a pink spring rate color. Your engagement RPM needs will determine the center color.

 

[PeeWee86]

As for your question about secondary spring twist; if you were using the Yamaha pink spring I would have suggested a 3/3 for a starting point. 6/1 will give better corner to corner and off trail responsiveness at the expense of lesser top speed and higher belt temperatures. The differences in the TP blue spring may alter these recommendations. Another question that Thunder Products should be able to answer for you.

 

[NOS-PRO]

It's not that they don't know....it's that they do not release their spring tensions to the public.

The midnight blue spring should be wrapped 6-1 or if you just trail ride, you can go down to 3-3.

Also what twist should I be using? I’m new to clutching. Currently has a stock helix, will be going to a reverse helix shortly just trying to get everything else working right. I’m not getting all my RPMs on a wot run. Only getting 8100 range. I’m putting a stiffer spring in the primary, currently a blue silver blue.

Right now you have the kit set as it should be, blue silver blue primary (and should have 2 glide washers, 1 each end of the primary spring). Stock helix is a 43° straight and works very well. If you are low on rpms, then some weight needs to be taken away from the weight tip and mid.

Post a pic of how the weight is currently set up please and @shagman and I will help you.

 

[ricer68]

Below are pics of the weights, the 3/4in slug in the heel of the weight. The sled will pull hard from a stop until 65mph then will fall off. Through the pull it will get up to 9000 ish on take off then mid 8's in the mid and fall down to 8000.

 

[ricer68]

Is knowing the rate of the blue spring all that important? The factory pink spring has been successfully used by many. It is tried and true. I would ask Thunder Products how the two springs differ and how their blue spring improves upon the factory pink spring. Even if they don’t know the rate of the blue spring they should be able to answer these other questions. If you do ask them these questions please post their response.

View attachment 137914

I am a believer in choosing a cam angle(s) based on torque sensing needs (stronger up shift or back shift) and load first, and then tuning the primary clutch for target rpm. If you already plan on changing the cam I would do that first before I spent too much time finding your target rpm with your existing cam. With that being said, I did look at the Yamaha spring chart and I agree that your existing blue-silver-blue is probably two weak for optimal performance. I would try a green or possibly a pink spring rate color. Your engagement RPM needs will determine the center color.

Another guy I talked with suggested a Dalton Red spring, which i happen to have one from my Apex. The spring rates on it are 40kg and 133KG total.

 

[NOS-PRO]

I'm assuming you didn't get the hardware kit with the purchase of the sled.....

If you did receive the hardware kit, I would take the 3/8 steel and thick washer out from the tip and put in a 3/8 aluminum with a thin washer in the middle and the tip . Try that first.

The midnight blue spring is made for the kit you have. You can twist that spring up to 6-2 to keep your top rpm's up also.

 

[ricer68]

I'm assuming you didn't get the hardware kit with the purchase of the sled.....

If you did receive the hardware kit, I would take the 3/8 steel and thick washer out from the tip and put in a 3/8 aluminum with a thin washer in the middle and the tip . Try that first.

The midnight blue spring is made for the kit you have. You can twist that spring up to 6-2 to keep your top rpm's up also.

I have the hardware kit, so I can change the weights around. I'm going to check the spring twist after I get the primary back togther. I know on the helix its at 6 not sure on the shieve side, wasn't sure where to set that at.

 

[ricer68]

I'm assuming you didn't get the hardware kit with the purchase of the sled.....

If you did receive the hardware kit, I would take the 3/8 steel and thick washer out from the tip and put in a 3/8 aluminum with a thin washer in the middle and the tip . Try that first.

The midnight blue spring is made for the kit you have. You can twist that spring up to 6-2 to keep your top rpm's up also.

What does changing the spring twist on the secondary affect?

 

[ricer68]

The weights currently weigh 67-68g based on my digital scale. The base weight according o the paperwork is 58g.

 

[PeeWee86]

Another guy I talked with suggested a Dalton Red spring, which i happen to have one from my Apex. The spring rates on it are 40kg and 133KG total.

If you already own that spring I would try it. It only cost you about 15 minutes of your time to switch it out. Nos-Pro has also given you some recommendations that stick with the blue-silver-blue spring. He has a lot of experience with the TP set up. As a generalization changes with the clutch weights will make a bigger difference than changes with the spring.

Make only one change at a time and keep written notes of how the different calibrations have affected the shifting. You might believe that you will remember but written notes can be referenced a long time in the future. Your recollections may fade.

 

[Janne339]

I’m going through my clutches on 14 xtx. It has a thunder products heavy hitter kit in it. Does anyone know what the spring rate is on their blue secondary spring? I called them and they don’t know......

Yamaha silver..

 

[ricer68]

If you already own that spring I would try it. It only cost you about 15 minutes of your time to switch it out. Nos-Pro has also given you some recommendations that stick with the blue-silver-blue spring. He has a lot of experience with the TP set up. As a generalization changes with the clutch weights will make a bigger difference than changes with the spring.

Make only one change at a time and keep written notes of how the different calibrations have affected the shifting. You might believe that you will remember but written notes can be referenced a long time in the future. Your recollections may fade.

Like I said i'm new to clutching and trying to understand what does what. At this point I've had people tell me to take weight off and leave the spring, others have said at that weight I need a heavier spring. I'm just trying to make sense of everything and figure out whats the right way to get things working. The guy that said to go heavier spring didn't think enough weight could be removed to gain 800-1000 rpms? They currently have 8 or so grams that can be removed based on what my scale showed. 3.3 in the heal, .4 in the mid and 4 on the tip. The base weight is around 58 grams roughly. We don't have snow currently so I can't go out and test it without driving 4 hrs up into Michigan.