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Old 08-05-2010, 10:03 PM   #1
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Default Underdrive and Overdrive

Hi all ....

Another newbie question from my side.

I can't get my mind around the underdrive and overdrive concept - the one you pull with your fron wheels and the other you push with your rear wheels, but which one is which?

Which one is good and which one bad?

How much of which do I want since it make sence that much of one can't be good?

What effects do they have on the handling of car?

Thanks again for your help !!

Faan Pretorius
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Old 08-06-2010, 12:53 AM   #2
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Overdrive = pulling on the frontwheels, giving more on power steer but due friction also eating power and speed

Neutral = giving the best predictable and lineair driving car.

Underdrive = driving like rear wheels but when those wheels will slip the front will ad making it 4wd. It will give a loose end but because no friction the best topspeeds.

It is not which is the best, it is just which is needed on the track you drive.
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Old 08-06-2010, 02:23 AM   #3
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It depends on your drivetrain. Roelof drives 8th scale, which has a one-way on the front axle. In 10th scale there typically is a diff or spool in the front axle, which makes a difference here.

On a 10th scale, overdrive will give more steering off-power, entering a turn, and less steering on-power, exiting a turn. Underdrive will do the opposite.

When having a front diff or spool, overdrive and underdrive will always make your drivetrain inefficient. A front oneway solves this for underdrive, but makes you loose braking on the front wheels.
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Old 08-06-2010, 04:54 AM   #4
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My 1/8 = I wish I could go under drive even more. At the moment ....., I only get 2 - 3 pct underdrive max.

My 1/10 cars = I like driving underdrive definetely .... some car get 5pct, some 10pct underdrive. I feel more driveable consistency with that setup.
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