All day Viper Clutching..

[4strokeluvr111]

I don't own a Viper but still send thanks for all of your efforts!

 

[MrSled]

Nobody said if you won or not MrSled. Alot of work went into 106mph. Even more to 100mph. Glad you guys got it figured out in a day.

I didnt race anyone,.... the sled is about how I like it not how fast it is against someone else.... If I wanted to win sure wouldn't race with a Viper. I would ride a sled that could pull my 240lbs body quicker then the next. I am twice the size of you... I would never race you on the same sled unless I wanted to loose.

As far as getting figured out in a day... well we found what we liked in that day. There is always room for improvement. I still wrench 0n my 240HP Apex that still is not where I want it...

 

[stingray719]

Tom's sled (2015 XTX) has the Excel intake and exhaust on it. COTC with that sled did have a very nice low engagement and the pull to top speed was very linear. Very very smooth setup. If I recall, top rpm was around 9200 with a top speed of about 97-98. Ulmer's kit had a higher engagement speed with a better low and mid range pull. Top speed was 100 with an rpm of 9300. But we all felt the best setup on this sled was Excel's kit. Low and mid range felt the best and it pulled 100mph right at 9000 rpm.

The two short tracks were both RTX SE models. One was a 2014 with a Cobra track and still using the 2014 map (no reflash on this sled). The other was a 2015 RTX SE with the Ripsaw 2. These sled both have Ulmer's clutch machining done on them and have his clutch kit and exhaust. We started out on both of these using the Ultimax XS805. Which when tweaked for that belt had a great low and mid range pull. And topped out at 100 with around 9000rpm. We then switched one sled to the 8DN belt just to see the difference - and WOW was a difference. We changed nothing on the clutch setup other than the belt. When switching to the 8DN, we could only get about 70mph out of it. Any more and it would overrev drastically. That told us the setup needs to be completely difference for the 8DN. So changed the 2014 model setup back to Ulmer's recommendations (as the kit comes setup from him) and bang - 100mph at 9000rpm with great low and mid range.

Drag race - Two RTX SEs ... one with Ulmer's recommended setup, 8DN and Cobra, the other with our tweaked Ulmer setup, XS805 and Ripsaw 2. Wouldn't you believe it .. the two were dead even from stop to top speed. They were both even from a roll-on start to top speed. If any sled had an edge, I'd say the Ripsaw had a bit better traction.

The vendors that offer their kits put a lot of time, effort and money in coming up with what they provide. What we found is that if you have mods other than the clutch kit (such as intake or exhaust), their clutch kit seems to work best with their mods. Example - Excel's clutching worked best with Excel's intake and exhaust. All of these kits can be made to run the way YOU want them to. Some extremely smooth, others have great mid range and low end. But ALL can be made to run 100mph. My only recommendation is use whatever kit you want. Use whatever Vendor or setup you like the best. In the end you will likely be happy.

If you do this again please increase the shim size on the primary spring on the COTC setup as part of the test, in my testing this makes the low and mid range much better and improves response. Might drop a mile an hour or two on top but the fun factor goes up. But many thanks for testing this.

 

[MrSled]

If you do this again please increase the shim size on the primary spring on the COTC setup as part of the test, in my testing this makes the low and mid range much better and improves response. Might drop a mile an hour or two on top but the fun factor goes up. But many thanks for testing this.

I had 2 shims... how much more you want next time?

 

[Studroes144]

I think everyone selling a clutch kit should provide their kit to a legit source and have them all tested back to back on the same exact sled, everyone thinks their setup is the best, that's good, they should have confidence in their product, why not try to prove it in a head to head comparison.

 

[stingray719]

I had 2 shims... how much more you want next time?

2 shims for 2mm for top end
4mm for all around performance
6mm for low and mid for those not caring about top speed (not a setting I would imagine trail riders might want)

Thanks!

 

[MrSled]

2 shims for 2mm for top end
4mm for all around performance
6mm for low and mid for those not caring about top speed (not a setting I would imagine trail riders might want)

Thanks!

So that would change the engagement with every 2mm of shimming?

 

[stingray719]

So that would change the engagement with every 2mm of shimming?

Yes.

 

[MrSled]

Yes.

How much should be expected?

 

[fasteddie15x]

What belt did you think had the best over all performance?

I currently run an 8DN but was thinking about trying an aftermaket.

 

[Muffin]

I think everyone selling a clutch kit should provide their kit to a legit source and have them all tested back to back on the same exact sled, everyone thinks their setup is the best, that's good, they should have confidence in their product, why not try to prove it in a head to head comparison.

Who would this imaginary "legit" source be? You have to remeber that they do spend a lot of time and money putting the kits and settings together. They just don't dream these things up and hope to sell kits and dupe us out of hard earned cash.

I stick with reputable suppliers, ones that have been honest and are around year after year and are always willing to answer my questions no matter how lame or silly.

Here at Muffin Works we are no different. We try to do our very best to come up with useful and quality products. Sometimes we end up with less than stellar sales and results but we stand behind them all and service all of our customers as best we can. I think you could expect no less from what ever company you choose for a clutch kit.
Just do your research, and talk to the suppliers and most importantly make sure you tell them up front your weight, riding style, and most importantly what your expecting from the clutch kit. Do this and I'm sure you'll be a very happy camper

I know I'm being vague and I apoligize as I'm don't wish to endorse any one supplier or setup.

 

[Muffin]

What belt did you think had the best over all performance?

I currently run an 8DN but was thinking about trying an aftermaket.

If you read a little earlier in this thread we found that belt manufacturer made no difference in performance, but a belt change will force you to change your clutch setup to get the same results. My bother and I basically have identical sleds, I'm now running the Yammi 8DN and he's running the Ulimax and after the clutches were setup for the different belt compunds the sleds have virtually the exact same performance numbers. Keep in mind the most of the clutch kit suppliers kits and setup numbers are for the 8DN. In a nutshell, after market belts are stickier and will pull your RPM's down so you have to adjust the clutch weight (lighten) and secondary wrap to gain back those revs.

I ran an aftermarket for years thinking it was better but now with a full day of testing and learning more about clutching. I'm just going to stick with the cheaper and easier to get stock belt.

A side note on Belts:
We had several Ultimax belts and 8DN belts. All the OEM belts measured EXACTLY the same. We saw the length of the Afermarket belts very up to a 1/2" in length and all were longer than the OEM.

 

[TD Max]

The two short tracks were both RTX SE models. One was a 2014 with a Cobra track and still using the 2014 map (no reflash on this sled). The other was a 2015 RTX SE with the Ripsaw 2. These sled both have Ulmer's clutch machining done on them and have his clutch kit and exhaust. We started out on both of these using the Ultimax XS805. Which when tweaked for that belt had a great low and mid range pull. And topped out at 100 with around 9000rpm. We then switched one sled to the 8DN belt just to see the difference - and WOW was a difference. We changed nothing on the clutch setup other than the belt. When switching to the 8DN, we could only get about 70mph out of it. Any more and it would overrev drastically. That told us the setup needs to be completely difference for the 8DN. So changed the 2014 model setup back to Ulmer's recommendations (as the kit comes setup from him) and bang - 100mph at 9000rpm with great low and mid range.

Drag race - Two RTX SEs ... one with Ulmer's recommended setup, 8DN and Cobra, the other with our tweaked Ulmer setup, XS805 and Ripsaw 2. Wouldn't you believe it .. the two were dead even from stop to top speed. They were both even from a roll-on start to top speed. If any sled had an edge, I'd say the Ripsaw had a bit better traction.

Could you elaborate a bit on what the clutching changes were between the two belts?

I assume with these aftermarket belts they run a common compound with each series and then just alter the length. Is the XS805 the 8DN or 8JP equivalent?

1T 2W in heel, nothing center, 1W tip I assume?

Red secondary 6-2 wrap and K helix?

 

[1tp]

Interested in hearing what Excel's recommendation is.

 

[MrSled]

Interested in hearing what Excel's recommendation is.

Do you have his Intake Kit?