14 rtx top speed

[ViperBill]

Got back last night from testing a new clutch set up on my base rtx. Running drag n flys 5.2g in the heel 3.2 in the base no weight in the center, tip or overdrive. In the secondary the stock cam with a polaris red spring on 9/3. the polaris spring is much longer with fewer wraps and is more of a compression spring. rode trails most of the day clutchs ran very cool and felt great. in the afternoon we hit a river ungroomed well packed. I wouldnt think they were very fast conditions but smooth with good traction. Sled got up to 9050 and pulled hard well past 90mph and topped out at 99. my buddy was on a 800 axys said he was at 103 and i was pulling away. We put another guy on it that weighs 150 and he said he saw 101. rpm at top did pull back to 8950. Sled is stock except for dupont slides. I have also found you have to run the tracks loose on these machines. I run 2in of sag with no weight on the track. the duponts are wider than origonal nso the track doesent walk when ridden but rolls mutch freer at high speeds. So far very happy with this setup. In 3500 miles this sled has never done better than 90 in any conditions so this is a huge improvement for me!!!

 

[ViperBill]

forgot to mention primary spring is the black spring that cam with the kit i believe its a 160/400

 

[fourload]

I put the duponts on my Nytro XTX at the beginning of this season and they are great. The sled rolls much better in hard pack conditions. The track clips remain cool to lukewarm after a long full throttle pull. Speedo readings yesterday on hardpack were 105-6. My friends Viper was in the 95mph range. Both are stock otherwise. I believe part of the problem on these Vipers is drivetrain friction. This week we are changing out my friends sliders to duponts and putting on a DN belt. We are on a mission to make his Viper even with my Nytro!

 

[ViperBill]

Iam still running the 8jp. Since i changed the secondary spring i have had no dusting/slipping issues. the longer dn will cost ratio as it wont pull down as far in the secondary. I beliece there is more speed in the shorter belt if clutched properly. the stock secondary spring is short and only relies on upshift force to grip the belt. at steady speed or decell they loose the grip on the belt and slip. i think that is where a lot of the dust comes from. The difference has beed dramatic. i no longer get any noticeable dust or slippage and the belt runs cool. when we ran yesterday it was 33f and the sun was out i think on a cold day it would run even faster.

 

[fourload]

I believe you are right about the JP. I have been told by NOS pro that his sons NYTRO ran faster with a JP belt also when a cut helix and the correct secondary spring was used.

 

[Nytro40th]

I ran drag and fly on my nytro red spring in primary, stock helix and spring in secondary, I forget where my weights were, I think mostly in the arm and heel as well. It pulled like a freight train, in the powder was so so, but was not an issue for me. I run the 8jp on my viper with the osp float and Ulmers clutch. 1 tungsten 1 washer in heel, centre 0, tip 1 washer, ulmer helix.