Clutch test - new info

[yamadoo]

Terry/ Nos Pro I can't wait to get the LTX set up!!!!

 

[Moravec]

Ok so just to double check I have read the entire post again before I order parts, as far as I can tell I need to order a 3 mm shim for drive a 8dn belt and a o/s/o. Spring. This setup will not rip my arms off but will still be ok at mid and top.

 

[stingray719]

Ok so just to double check I have read the entire post again before I order parts, as far as I can tell I need to order a 3 mm shim for drive a 8dn belt and a o/s/o. Spring. This setup will not rip my arms off but will still be ok at mid and top.

After using several springs I would recommend the Green/white/green that came in the Nytro mountain. That and the 3mm or 4mm shim. NOS PRO what weight did you end up with in your flatland setup? (he is running the shim and has done ALOT of lowland testing for weights) 8fp and what rivets? Thanks!

 

[NOS-PRO]

Terry/ Nos Pro I can't wait to get the LTX set up!!!!

 

[NOS-PRO]

After using several springs I would recommend the Green/white/green that came in the Nytro mountain. That and the 3mm or 4mm shim. NOS PRO what weight did you end up with in your flatland setup? (he is running the shim and has done ALOT of lowland testing for weights) 8fp and what rivets? Thanks!

Oh man, I didn't even see your post until now bud....sorry about that.

The weight I ended up with was 72.6 - 73 grams. (8FP weights with a 3 gram rivot in the tip, GWG with 3mm spacer in the primary and stock rollers) secondary was pink spring set at 6-1 with a 45/39 helix with washers under the helix to prevent coil bind.

Now, I am REALLY throwing weight at the Viper now for asphalt and I'm up to almost 77 grams with the same 8FP weights, 3 gram in the tip and a 4.5 gram in the heel. Helix is a 53/47 and it is taking it!
Should see the black stripes on my road in front of my house

 

[NOS-PRO]

After a lot of testing this weekend, the weights I have in the Viper now, DO NOT like a lot of heel weight added. The Viper does not like a lot of helix either. Tried all kinds of helix's and weight combinations. I am very close to my original setup I ran on the snow....with the exception of adding tip weight and a white secondary spring instead of a pink (stock). It likes to be on the 8,900-9,000 peak all the time, not like the apex where you can clutch 10,200 and still pull like it's clutched at 11,000

 

[Studroes144]

Same exact outcome we had first thing this past winter. Can't lug the viper along, it's gotta zing right up to 9000 and hold steady and the biggest problem with that is the low rev limiter. This sled can over rev 200-300rpm and still be very fast but the rev limiter kills it.

 

[NOS-PRO]

We are working on this issue

Very fine line between the peak power and the rev limiter

 

[Studroes144]

Good chance that I'll be able to get some ecu tuning done during the turbo process and one of the things on the list is to raise the rev limiter. Clutching around it is nearly impossible as it's been tried all season by myself and a couple other guys..clutch too low and it's gutless, too high hits the rev limiter..you can get it in the sweet spot one day and the next day on slightly different conditions it's way off. Rev limiter increase will solve a lot of issues. H

 

[stingray719]

Good chance that I'll be able to get some ecu tuning done during the turbo process and one of the things on the list is to raise the rev limiter. Clutching around it is nearly impossible as it's been tried all season by myself and a couple other guys..clutch too low and it's gutless, too high hits the rev limiter..you can get it in the sweet spot one day and the next day on slightly different conditions it's way off. Rev limiter increase will solve a lot of issues. H

What belt are you running?

 

[Studroes144]

Stock belt. I tried 8dn for a day and I didn't notice any difference. But At that same time I never had the clutch issues other people were talking about. Mine was a box stock 100mph sled. Now with clutching it's a tad faster and much quicker so I never fussed at all with running the 8dn. As of now mine is setup to ping rev limiter once or twice on the launch and then sit right at 8950-9000. As I talked earlier in the year some, this setup was leaving many 800s for a long ways on a drag race..the same sleds that on a roll on were 2-3 sled lengths faster. Ive been pretty fussy with my clutches tho as in 2300 miles I had clutches off 4 times and completely disassembled and cleaned them as well as really keeping the clutch faces clean so the belt dust didn't cause issues. My biggest problem was with the chassis itself causing quite a lot of rolling resistance and I'd be willing to bet that even still, a lot of the issues people are finding are tied back to the chassis just working against the drivetrain and the belt and clutches being the weakest link. Since I added all the extra wheels and DuPont slides I never had a problem getting 100-102 mph in most any condition where as before that the speed problem kept getting worse. my sled went from 100 mph sled out of the box to gradually being an 85 mph sled, back to a 100+ mph sled with simply adding wheels and new slides. The rolling resistance caused clutch issues..but the clutching wasn't the issue. With the chassis not rolling well I got tons of belt and clutch heat which only kept getting worse. Certainly other peoples experience is different than mine but the research that I did and the arctic cat procross guys I talked to all said the same thing and that is that the stiff suspension and lack of wheels causes the most all around issues with the sled

 

[STAIN]

I was told by a known turbo tuner to be careful over revving these engines ----you can bend a valve.

 

[stingray719]

Stock belt. I tried 8dn for a day and I didn't notice any difference. But At that same time I never had the clutch issues other people were talking about. Mine was a box stock 100mph sled. Now with clutching it's a tad faster and much quicker so I never fussed at all with running the 8dn. As of now mine is setup to ping rev limiter once or twice on the launch and then sit right at 8950-9000. As I talked earlier in the year some, this setup was leaving many 800s for a long ways on a drag race..the same sleds that on a roll on were 2-3 sled lengths faster. Ive been pretty fussy with my clutches tho as in 2300 miles I had clutches off 4 times and completely disassembled and cleaned them as well as really keeping the clutch faces clean so the belt dust didn't cause issues. My biggest problem was with the chassis itself causing quite a lot of rolling resistance and I'd be willing to bet that even still, a lot of the issues people are finding are tied back to the chassis just working against the drivetrain and the belt and clutches being the weakest link. Since I added all the extra wheels and DuPont slides I never had a problem getting 100-102 mph in most any condition where as before that the speed problem kept getting worse. my sled went from 100 mph sled out of the box to gradually being an 85 mph sled, back to a 100+ mph sled with simply adding wheels and new slides. The rolling resistance caused clutch issues..but the clutching wasn't the issue. With the chassis not rolling well I got tons of belt and clutch heat which only kept getting worse. Certainly other peoples experience is different than mine but the research that I did and the arctic cat procross guys I talked to all said the same thing and that is that the stiff suspension and lack of wheels causes the most all around issues with the sled

I asked because the trademark issue of the 8jp belt was not running the same each time out. But if you are happy run it.

 

[Studroes144]

I was told by a known turbo tuner to be careful over revving these engines ----you can bend a valve.

Certainly not going to be revving it to 10k..but the engine should be allowed to atleast get in the 9200 range since the sweet spot is 9000

 

[stingray719]

Hey I bought two sets of 8FP weights from hibshman25 who is an advertiser here, for $75.00 a set in case you need a set. He shipped promptly too no complaints from me.