Decent "slipper" style clutches that won't break the bank?

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forcefed86

Member
#1
#1
Are we pretty much stuck paying $300'ish if we want a decent "race" clutch that will allow a high stall and "slip". Racing minibikes to 300ft in a group. Currently use a torque converter which has more than enough grunt off the line. I pull way out front and then get passed 3/4 track or so by the (standard style) clutch guys. Just losing too much power due to slippage on the converter. Not wanting to give up all my "launch" power if possible.

One race has the viper 2 disk 6 screw adjustable clutch and it's great. But the price tag ans constant rebuilds have be searching for a possible middle ground?
 

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massacre

massacre

#2
#2
I used a triple disc SMC vortex clutch, with the roller fingers and it cost me about $400.
Worked really well but i was winding the engine to 9000 rpm lol
The jr dragsters race 330ft and they use Polar style clutch or similar. They are completely tunable, and the driven has rollers instead of buttons, and has overdrive.

when i made the switch from the triple disc to the polar, it made a huge difference in launch and in top end.
 
delray

delray

Well-Known Member
#5
#5
I have been running old 340 salsbury and it comes out of the hole so hard. driver part seems to do the job well,but the driven(7inch 20series) likes to slip at mid to top end when running any strong engine with it. I got couple thing to try out maybe to help fix the problem.
I did run a good norman drum clutch on a bike this summer for drag racing 125ft and was very impressed how it work over using a torque converter setup. with a TC unit I needed to run also a weld on jack shaft unit to help gear the bike to pull 7200 at 125ft. I just might be totally done with the TC unit. I feel that I have to use extra hp just to turn all the extra stuff...for example driver,driven,belt that likes to maybe slip little and it never 100 percent lock up,extra jackshaft..two gears...5/8 shaft..5/8locking collars,extra chain. not good when your trying to get the most out of your motor in 125ft.
with the clutch set up all I had to run was the clutch into a small jackshaft that was already built into the bike(rupp) and out the back to the rear sprocket. mid-range to top end acceleration was super fast. now I am running less material to spin(saving hp) and it's 100 percent direct drive. one thing I have learn is getting the stall/rpm's spot on and gearing when going with a clutch only setup. disc clutch will be something for me i will be looking into this winter....
 
F

forcefed86

Member
#9
#9
VEry nice all! We are restricted to a 212 predator engine. Was looking for cost effective clutch unit that can actually launch. The 340 salsbury and like $400 triple disc's are a bit out of my budget range. Any "beefy" standard style clutches fit the bill?
 
delray

delray

Well-Known Member
#10
#10
well if your restricted to a 212 and also still using a stock style head that is modified internal only. for example it's not a Charles design head with ton of extra welding done to it with a 28mm or bigger carb. then a Noram GE Ultimate Clutch will work all day on that engine with engagements springs from 3000+ up to 4000+ . that clutch will not give up on you for drag racing only.

I was so happy with my noram clutch this summer I am thinking about stepping it up for my crazy drag engine next summer and the clutch is there disc clutch and it's not $400 dollars either. also little plug for OldMiniBikes warehouse....free shipping over $150 I believe.

if you are on a real budget and your stall speed fits the application. you can cheat little with a max ss clutch and take it apart and cut 3 shoes in half. every other one. 6 shoes in it total and take your 3000 spring and shorten one or two loops. this must be done correct. this will give you another couple hundred more stall out of it.
 
Charles S

Charles S

#11
#11
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