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Harold Hammerly
Joined: 24 Jan 2012 Posts: 24
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Posted: Fri Apr 20, 2012 5:22 pm Post subject: Wf |
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I would appreciate some advise on a starting point for gearing JA kart with a world formula engine, I seem to get to over 60 mph often on my supercharged Miata at our local events (Grissom) will a JA run about the same speed?
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Alan Sheidler
Joined: 09 Aug 2001 Posts: 473
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Posted: Fri Apr 20, 2012 6:05 pm Post subject: Re: Wf |
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| Harold Hammerly wrote: | I would appreciate some advise on a starting point for gearing JA kart with a world formula engine, I seem to get to over 60 mph often on my supercharged Miata at our local events (Grissom) will a JA run about the same speed?
Thanks |
17 front (clutch gear) and somewhere around a 60 to 65 axle. Note: We have run only the #35 chain, if that makes any difference. The tallest we ever geared for an autocross was a 56 rear, and that was way too much. It killed off-corner acceleration. We put on a 68 once, much too short for all but the smallest lots with no real straights. Most autocrosses seemed to want around a 63. Still, I advise all WF families to gear so that the rev-limiter is never hit, or maybe just hits once in the fastest spot on a course. We had to shorten the gearing at Pittrace kart track (Beaverun) last Thursday and allow limiting on the main straight, because the clutch was not happy in the very tight (way tighter than any autocross corner) inside loop with adult riders. IIRC we used a 61? Or maybe it was the 63. We took off a 57 I think, no limiting anywhere, but a bummer in slow spots.
A JA kart will out-corner your Miata, but should not accelerate nearly as well. Still, depending on the course layout, speed could top 55 with an aggressive driver. |
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Harold Hammerly
Joined: 24 Jan 2012 Posts: 24
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Posted: Fri Apr 20, 2012 7:39 pm Post subject: Wf |
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Great, now I know where to start gear wise, I was going to change chains to a #35 because the lower price of the chain and availability of smaller split axle sprockets.
What oil catch can do you run? I see some builders run a tube from the valve cover to the oil fill port
Thanks again |
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