Clutch drivers
- Thread starter a542m
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alvin l nunley
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Just assuming you understand, but are you talking about with the same gear ratio.
There are 2 camps here, one says there are times when you should switch to a bigger driver, (nobody has ever explained the process, or criteria, by which you make this decision. Black magic I suppose. lol) same ratio, and one says it makes no difference, a ratio is a ratio. You can believe one or the other, or you can test it for yourself. Do what is best for you.
Make sure your testing is well controlled. Go back-and-forth a few times. Dirt tracks have a habit of changing through the day. The air density can change, be sure you keep your eye on that. Going from a hot afternoon to a cool evening can make a difference in performance.
Uh-oh
^^^ nicely done...lol
Someone ...
Member
Actually, why you might choose different driver gears has been explained on this site before (several times), and no it is not black magic, and although "a ratio is a ratio" may be true mathematically it is not true in real world applications. There are many long threads here arguing about gear selection.
What it boils down to is the torque curve your engine produces, vs. how you load the engine.
The Predator, if you leave it stock with its original cam and its governor, can produce a fair amount of torque but it can't rev very high. So many people pick larger driver gears to utilize that torque and then tolerate the top r.p.m. limitations. If you modify your Predator then what you'll need depends upon what you build, but generally modified engines will rev higher (at the sacrifice of some torque) so you might want to drop a tooth or two on your driver gear.
“Loading” refers to the work the engine has to do to make the kart go around the track. Several things affect it, such as overall vehicle weight (including driver), tire grip, throttle manipulation, and driving line (particularly how well you can keep up momentum). If you find that (once you get going) you can keep momentum up then usually you can utilize a bigger driver gear.
It is true that track conditions will change throughout the race day / night – especially on dirt – so optimum gearing will change. Weather changes can also effect this (including temperature changes before and after sunset). But most people find they can compensate by changing driven gears.
What it boils down to is the torque curve your engine produces, vs. how you load the engine.
The Predator, if you leave it stock with its original cam and its governor, can produce a fair amount of torque but it can't rev very high. So many people pick larger driver gears to utilize that torque and then tolerate the top r.p.m. limitations. If you modify your Predator then what you'll need depends upon what you build, but generally modified engines will rev higher (at the sacrifice of some torque) so you might want to drop a tooth or two on your driver gear.
“Loading” refers to the work the engine has to do to make the kart go around the track. Several things affect it, such as overall vehicle weight (including driver), tire grip, throttle manipulation, and driving line (particularly how well you can keep up momentum). If you find that (once you get going) you can keep momentum up then usually you can utilize a bigger driver gear.
It is true that track conditions will change throughout the race day / night – especially on dirt – so optimum gearing will change. Weather changes can also effect this (including temperature changes before and after sunset). But most people find they can compensate by changing driven gears.