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Ricky Brown
Joined: 28 Oct 2012 Posts: 31
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Posted: Tue Dec 18, 2012 4:33 am Post subject: wf clutch |
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| Has anyone running world formula tried playing around with different clutch springs? If so can you explain how they work? If you use a spring that engages at lower rpm would you get better acceleration or would it work the opposite way ? More acceleration by letting the motor rpm's come up before engaging? Also, any other tips or tricks with these clutche would be greatly appreciated! |
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Bernie Lacotta
Joined: 21 Mar 2006 Posts: 168
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Posted: Tue Dec 18, 2012 7:53 am Post subject: Re: wf clutch |
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| Ricky Brown wrote: | | Has anyone running world formula tried playing around with different clutch springs? If so can you explain how they work? If you use a spring that engages at lower rpm would you get better acceleration or would it work the opposite way ? More acceleration by letting the motor rpm's come up before engaging? Also, any other tips or tricks with these clutche would be greatly appreciated! |
I've used the yellow springs on occasion,just to experiment. You are much better off staying with the orange springs. By the way,the springs are VERY difficult to change without the proper equipment,impossible to do at the track. It is not uncommon to break a spring while racing,it locks up the clutch,you won't know it until you come to a stop off until you pull off the track and stop. It's a very good idea to order and carry a spare cassette with you.Easy to change compared to the springs. _________________ I breathe ,therefore,I race |
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David McDowell
Joined: 01 Oct 2011 Posts: 64 Location: United States, California, Mt Shasta
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Posted: Tue Dec 18, 2012 10:31 pm Post subject: Re: wf clutch |
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| Bernie Lacotta wrote: | | Ricky Brown wrote: | | Has anyone running world formula tried playing around with different clutch springs? If so can you explain how they work? If you use a spring that engages at lower rpm would you get better acceleration or would it work the opposite way ? More acceleration by letting the motor rpm's come up before engaging? Also, any other tips or tricks with these clutche would be greatly appreciated! |
I've used the yellow springs on occasion,just to experiment. You are much better off staying with the orange springs. By the way,the springs are VERY difficult to change without the proper equipment,impossible to do at the track. It is not uncommon to break a spring while racing,it locks up the clutch,you won't know it until you come to a stop off until you pull off the track and stop. It's a very good idea to order and carry a spare cassette with you.Easy to change compared to the springs. |
The reason I found for going to a weaker spring was to have the clutch engage sooner and prevent clutch slipping on the one very slow corner on our track. As for changing the springs that is very easy with a rubber mallet and a D-Cell Maglight head once you have done it once. I can now change the springs in as little as 5 min once the clutch is off the engine.
To use the Maglight:
Take bulb head off of body.
Place clutch hub on top of bulb head.
Hammer down the taper of the bulb head.
Take off old springs and install new ones.
Reverse to re install shoes on hub. |
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Ricky Brown
Joined: 28 Oct 2012 Posts: 31
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Posted: Wed Dec 19, 2012 3:47 am Post subject: clutch |
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| Great info so far! Keep it coming, there doesn't seem to be a lot of info on the wf any where!?! |
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Bernie Lacotta
Joined: 21 Mar 2006 Posts: 168
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Posted: Wed Dec 19, 2012 8:33 am Post subject: Re: clutch |
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| Ricky Brown wrote: | | Great info so far! Keep it coming, there doesn't seem to be a lot of info on the wf any where!?! |
Ricky,check your pm's _________________ I breathe ,therefore,I race |
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David McDowell
Joined: 01 Oct 2011 Posts: 64 Location: United States, California, Mt Shasta
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Posted: Wed Dec 19, 2012 9:26 am Post subject: |
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Ricky
I think the main reason you don't see much info on a WF is due to the fact that the class is pretty much box stock and builders don't want to give out the few tricks there are to perform on the motor. If you read the rule books there is nothing you can really do to them.
David |
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John Matthews
Joined: 04 Dec 2004 Posts: 2013 Location: United States, Michigan, Williamsburg
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Posted: Thu Dec 20, 2012 9:37 am Post subject: |
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The World Formula is a great package straight out of the box which is how most folks should probably race them. For most club racers there's a lot more to be gained by driving and chassis set-up than tweaking the WF engine with the restrictive rules in place. The beauty of the package IMHO is it has enough power for most sprint tracks with a great torque curve that just makes driving fun, especially for us heavier guys.
But, that doesn't mean you can't make them better....
Engine building is a learned skill just like driving, the more you do the better you get at it. All the information needed is easily available, you just need to be willing to look for it and try a bunch of different things so you understand how all the little things you can do actually work together.
There are lots of great amateur builders who also race so if you're committed to the class and you have the desire to work on your own engines you should give it a try, at the very least you'll understand how your engine works a little better
Cheers, _________________ John Matthews
Heartbeat Power, LLC. |
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George Vorrilas
Joined: 11 Feb 2007 Posts: 231 Location: United States, Massachusetts,
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Posted: Sun Dec 23, 2012 12:44 pm Post subject: World Formula - Clutches |
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Rick, I agree that the orange clutch springs work the best. When we did the karts for the movie, we tried many variations of spring rates due to the crazy application and use of the karts. In short, the orange ones worked best by far. Regarding replacing them, once again, we ran 14 of these karts on set and got pretty good at changing springs in short order. Early on we tried to purchase a tool to replace the springs and came up empty handed. We then manufactured a tool that works perfect. Easy to dis-assemble and reassemble, 5 minutes max. We have it in the shop and will have it at all of the races, you are more than welcome to use it. We have also found that when you reassemble the clutch, it is imperative that you loctite the screws into the barrel nuts that secure the two clutch half plates. If not, they WILL back out. Use just enough loctite to secure the screws so it does not drip onto the sleeve in the center of the clutch..
Feel free to reach out to us if we can help. George V.
ApexKartSports
978-479-7974 |
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Ricky Brown
Joined: 28 Oct 2012 Posts: 31
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Posted: Mon Dec 24, 2012 4:33 am Post subject: |
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| Thanks George! |
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al nunley
Joined: 13 Nov 2006 Posts: 3065
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Posted: Mon Dec 24, 2012 10:57 am Post subject: |
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You want the clutch to hold the engine at peak torque. Peak torque “to” the axle means peak HP “at” the axle.
Try the bathroom scale trick.
Put a bathroom scale between a “strong” wall and the front of your kart. Sit in the kart and hit the gas. The stall RPM that gives you the best scale reading is the best place to set the clutch. Different springs will hold the engine at different RPM's _________________ If the data does not support the theory, get a new theory. (Al Nunley)
All else being equal; Compression is the Holy Grail.
45 years, in and around karting |
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George Vorrilas
Joined: 11 Feb 2007 Posts: 231 Location: United States, Massachusetts,
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Posted: Mon Dec 24, 2012 3:03 pm Post subject: Clutch stall speed |
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But Al, my bathroom door is only 30" and the rear track of my kart is 54" ?
Any ideas how to get the kart in and out of the bathroom without the bride noticing it ? And will the engine set off my smoke alarm, and CO2 alarms ?
Just kidding my friend, as always, a great info.. Thanks. BTW, World Formula is starting to really spread it's wings in the Northeast, guessing 20-25 karts this season.. |
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David McDowell
Joined: 01 Oct 2011 Posts: 64 Location: United States, California, Mt Shasta
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Posted: Wed Dec 26, 2012 4:53 pm Post subject: |
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| al nunley wrote: | You want the clutch to hold the engine at peak torque. Peak torque “to” the axle means peak HP “at” the axle.
Try the bathroom scale trick.
Put a bathroom scale between a “strong” wall and the front of your kart. Sit in the kart and hit the gas. The stall RPM that gives you the best scale reading is the best place to set the clutch. Different springs will hold the engine at different RPM's |
Just a questions but how do the springs hold the engine at different RPM's when the function of the springs is to set the RPM at which the clutch shoes engage. So the only reason to change the springs would be if the engines RPM on any track goes below the installed RPM and cause the clutch to disengage. |
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Dean Graves
Joined: 11 Sep 2001 Posts: 519 Location: United States, California, Lompoc (Lompton)
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Posted: Thu Dec 27, 2012 4:36 pm Post subject: |
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| Yellow springs. |
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Chris Hatch
Joined: 02 Mar 2004 Posts: 405
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Posted: Sun Jan 20, 2013 10:35 pm Post subject: |
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| Yellow springs = no chatter and smoother engagement. |
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