Viper Clutching debate

A

Almost700

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Nov 18, 2005
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I am in a dilema. I have a 780 Viper that I just put a 136 Ripsaw on and am having a clutching issue. It comes out REAAALL hard and about 150 feet out it sucks the belt up and drops 1000 RPMS and slowly climbs back up. I was thinking that I was going to throw some more Helix at it so it would up shift faster but am not sure that's the way to go. I am considering taking a little weight out of the middle hole (heavy hitters) to slow down the shift. Where would you go with this? Start with the primary or secondary? I am trying to visualize this and both seem to make some sense. Let me know please.
 
Need more info. What are you running in the sec. for helix and spring, and what twist? What primary spring, and weight in the hitters? Sounds like a combo of too much weight/too much helix angle/not enough twist.
 
No i was having the same problem... Try taking weight out of the last hole so it will keep the revs up. but yamahoilc is right.
 
Straight 47 Helix, spring wrap initially at 70, then I twisted up to 90, seemed to help a little. On cool clutches, it was not as bad as when they heated up. EGT temps same, clutch heat got hotter. At the beginning of the day, I had only small rivot in shoulder. I took it out and put the large rivot in. It pulled harder and really felt better. FYI, it is over revving a little bit still right now. That's what leads me to believe its in the secondary. From a roll on, it pulls smooth and hard all the way through so the engine is pulling it. Just from a dead standstill I am getting a helacious bog about 100-150 feet out. About when it starts really hooking. As far as what is in the tip and middle holes, not sure. I bought this sled from a buddy (SRXRacer on here) and am just tweaking it to fit my needs. I used his set up as a baseline so I have no Idea what is in there. I was planning to add and subtract as needed. Does this give you enough to go on?
Part of the problem is that it's not coming out real smooth. It's leaving so hard that it is bobbing a little bit and when it finally settles back and stops the bouncing is when it bogs. I am tuning the bounce out which will help the bog, but again, does this sound like primary or secondary to you? Remember, low speed roll ons show a very good shift curve as it slams to 9100 and creaps to 9400-9500. Your thoughts?
 
Oh, by the end of the day I had the shoulder completely loaded with a short and long rivot and it for sure didn't make the bog any worse than with just the long one.
 
Your gonna need a silver secondary spring wrapped at 60 degrees with that set up. Gonna need some fine tuning also.
 
Turk, I was hoping you would reply to this. It has a silver secondary spring in it now with the straight 47. I was first thinking of trying a 51/47 but a couple of people are suggesting that the problem is at the primary. It may be, but what does it sound like to you?
 
As far as fine tuning, I agree. I just want to focus that fine tuning in the right place (primary vs secondary). It will surely be a trial and error thing but to conserve some time I am obsorbing the knowledge of you guys to help me cut to the chase. The less chasing of my tail I can do the better.
 
personally i think that is too much helix. When you are spinning there isn't much load on the clutches, but then when it finally hooks it needs to backshift quick and it isn't doing it, it is already upshifted too far, the clutches get ahead of the engine, you hook and the load increases greatly, and the engine can't catch up with the clutches.
 
You allways want to tune rpm,s by using the primary weights & spring 1st & then fine tune with the secondary. Try doing it that way & I would try a dual angle helix. 51/43 works great & you can pick up used RX-1 helix,s cheap. They work very well.
 
Yes, less weight and less final angle on the helix, 47 is a lot to pull for a finish angle. As Turk said something around a 51/43 works great.
 
Turk and Yamaholic, you were exactly right. The rx-1 helix seemed to work out pretty well. Though in talking to Jeff Simon he said there is no way it would work. You were right, it does work. Now, it runs perfectly on the snow when I get some track spin but if I try to race on the road it still wants to to the same bog it was doing. It seems to like a VERY soft secondary. I have a pink secondary spring at 30% and am going back to silver at 60 per turk's recommendation. This might be the ticket. Thanks for your help guys.
 
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