I have a 780 Stage II Simons Viper. 136" Expert X w/ 1 1/4 track studded. The clutching WAS Hauck X Weights with 3.4 in first hole, middle empty and 4 in the tip. Secondary WAS 52/47 helix w/ silver yamaha spring at 80 deg. This set up gave good pull low and top range but was weak in mid. RPM were a consistant 9k all the way. To try to get better midrange pull I took the 3.4 out of the heel, lightened it to 3 and put it in the middle. Also set the secondary back to 70 deg. This gave better pull but slight RPM lag in mid to about 8600 RPM. I then lightened the milldle hole a little more to 2.2. Better RPM in mid but still a little low. The sled hits target RPM out of hole (maybe because of initial spinning) then bogs to 8700 then at about 70 mph it begins to pull RPM's back where they belong. How do I get rid of the mid range bog and keep the strong mid range pull? I think it might be doing this because it hits so hard out of the hole it causes the front end to come up, track then spins and when the front comes back down & gets traction again the secondary has shifted too far causing it to pull RPM's down. I think if I can make it come out of the hole softer and maintain mid range RPM it will be perfect. Any ideas? I am hesitant to take weight off the tip because my top end RPM is good. Wrap secondary tighter again? Change weight profile? 
Please help me.
Madmatt
Please help me.Madmatt
Loosen the secondary to 60 degrees & take some weight out of the middle hole.52/47 is pretty aggressive. I like the initial start angle but the finish angle is kinda high. I woulld look at something with a 42-40 finish.
Results -
OK Turk, looks like I was right about the spinning & overshift in the secondary. The spider was cut on the primary I was using and I was having trouble toning down the engagement RPM which was too high. (over 5k). I took the weights and spring and put them in a different primary w/ stock spider & sheaves. Engagement is much better (4400) and the sled comes out of the hole much better (softer). RPM's are good w/ no bog anymore because of more consistent traction. Low and mid pull is good but now I need to improve the top end pull. Sled kind of falls on it's face at 90. You mentioned my helix (52/47) being very agressive. Could the steep finish angle on my helix be causing this top end problem? Got any ideas? I'm getting closer!!!!!
Thanks for your help,
Madmatt
OK Turk, looks like I was right about the spinning & overshift in the secondary. The spider was cut on the primary I was using and I was having trouble toning down the engagement RPM which was too high. (over 5k). I took the weights and spring and put them in a different primary w/ stock spider & sheaves. Engagement is much better (4400) and the sled comes out of the hole much better (softer). RPM's are good w/ no bog anymore because of more consistent traction. Low and mid pull is good but now I need to improve the top end pull. Sled kind of falls on it's face at 90. You mentioned my helix (52/47) being very agressive. Could the steep finish angle on my helix be causing this top end problem? Got any ideas? I'm getting closer!!!!!
Thanks for your help,
Madmatt
That finish angle will definately give you poor hi speed belt squeeze & drop rpm,s. I will tell you again to get the same start with a 42-40 finish angle.
Thanks Turk
Thank you Turk. I presume that when I get my hands on a helix with the 40-42 finish angle I will need to add weight to the tip?
Madmatt
Thank you Turk. I presume that when I get my hands on a helix with the 40-42 finish angle I will need to add weight to the tip?
Madmatt