03 sx viper (Frankinsled) 90 mph max

D

David Mcfadzen

Member
Joined
Jan 20, 2017
Messages
35
Location
New Brunswick
Hey everyone, finally after a long summer I finished my skid conversion to a 136 inch mono from an 09 vector. Everything went well and running strong but seem to be slow at top end. Things i have done and specs are as fallows.
136 ripsaw 2 with 108 studs.
8 tooth extrovert drivers.
Swapped 22 tooth top gear for a 23.
Www secondary and silver primary.
8DN 10 weights with 2 - 4.5 gram rivets (also added another 1.5 gram of salder to the tips to have it ingadge at 3500 and run to 8550 and stay there.
51/43 helix
Cleaned power valves but haven't adjusted yet.
Also plenty of sexy powder coat to pretty her up a little;-)
The machine does take off like a scalded cat but shouldn't it be able to reach 100mph or should I just live with it? Was thinking i could go down from a 38 lower gear to a 36 or 37 but yamaha doesnt make one thats reverse friendly also the 23 top was as big as i could get :( Any advice would be greatly appreciated. Best regards, Dave
 
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I'd probably start with making sure your powervalves are adjusted.

Might have to flip your sled back over as it appears you've rolled in your avatar, (poor attempt at humour)
 
Thanks for the response and Yes I tried updating my pic buy won't let me for some reason from my phone:(
also forgot to mention that the 90 mph was on gps, dash was reading 105 lol so working on grinding teeth to get that dialed in.
 
Very Interesting!

Hope you don't mind if I compare info...
2000 Venture 700 ( Non powervalve engine of course)

-Cobra 1.35x136" track, no studs
-9 tooth drivers, 22 / 39 gears
-stock 8ch weights + 2.8g added to tips, pink spring
-Apex 51-43 helix, green spring @ 80
-Very responsive and pulls hard till 75 mph
-WOT rpms 8500ish
-Top speed on gps 88mph
 
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Take those drivers out and this them. They are for slow sleds. Go back to 9 tooth. Ripaaw with 1.2 studs. Trim the track down if you want more bite. Make sure your track is cut for clearance to your guards.
 
I appreciate your opinion betheviper, but from my research switching from a 9 tooth to 8 tooth is equivalent to 1.5 teeth on my top gear so I'm only a half a tooth away from stock and I enjoy having my 1.25 lug
 
I think what Betheviper is getting at is as much as 8 tooth drivers give more clearances for larger lugs and studs, the tighter arc of the track around the drive sprockets create more drag and eat up more hp / top speed then 9 tooth drivers. But don't feel bad, your still faster then me! ;)
 
the 8 tooth drivers for sure will eat up some topend, they are not needed for just a 1.25 lug track but they are already installed...however, your use of a silver secondary spring is also eating up the topend. You could easily use the green dot sec. spring and run it at 60-70 twist. The silver sec spring is stiffer then the green and will eat up topend if not run very loose, its too stiff for the rest of your clutch parts. Start there and see, you should pick up some topend speed for sure.
 
ac auto said:
90 mph with the track and suspension choices you have made, sounds about right.
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Ya, What I thought too. Nothing but go-slow parts installed and now want's speed. I believe the 105 speedo vs 90 GPS. Always slippage at speed and the track/driver change is going to change speedo calibration.

I've run against stock Vipers on the river and they aren't that fast to begin with. 90 sounds great with the changes made.

opsled
 
David Mcfadzen said:
I appreciate your opinion betheviper, but from my research switching from a 9 tooth to 8 tooth is equivalent to 1.5 teeth on my top gear so I'm only a half a tooth away from stock and I enjoy having my 1.25 lug
Click to expand...
You eat up a lot more horses doing that. Turning a stiff frozen track is much harder than turning gears and a chain that’s bathing in oil.
 
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