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  #1  
Old 02-23-2008, 03:02 AM
BustedRotor BustedRotor is offline
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Exclamation Drifting Issues

I threw on some plastic tires onto my M18, and realized that it was spinning out too much. I took a closer look at the car when it was running, and saw that when the front wheels turn right the rear left tire wasn't spinning and the same for the left turn. I was thinking it could be the differential, but am not sure. Any feedback would be greatly appreciated.
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  #2  
Old 02-24-2008, 06:34 PM
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harnois harnois is offline
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"I took a closer look at the car when it was running, and saw that when the front wheels turn right the rear left tire wasn't spinning and the same for the left turn."

Was it on the ground being driven when you made this observation? Or were you holding the car in your hands?

Also is this the first time you've tried drifting or do you already know how to do it?
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Old 02-25-2008, 01:10 AM
BustedRotor BustedRotor is offline
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The car was against my foot, with the front bumper against my shoe. When I lightly hit the throttle all wheels engaged (with drifting tires on), but when I turned the wheel either right or left, the opposite rear wheel to the turn was not spinning... more like free wheeling.

This is my first time drifting and dealing with 1/18. I drifted and raced 1/10, but that was a couple of years ago. I know it shouldn't be too much different (shaft driven 1/10), but I just wanted to ask here to see if anyone was getting the same problems I was getting, before digging into the car.
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Old 02-25-2008, 01:58 PM
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harnois harnois is offline
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If you still have the stock front A-arms on the car, then you have 12 degrees of caster. What that does is when you turn right (for example), the chassis will lean left. When you steer right the inside front wheel actually travels downward and the outside front wheel travel upwards, all due to the castor. That in turn makes the inside rear wheel lift off the ground. And then of course the rear open diff allows that inside rear wheel to spin up and the outside rear wheel to stop.

You can see what I'm talking about very clearly if you put the car on a table, leave the front wheels on the table, but put something under the chassis at the back to take both rear wheels off the table. Then, don't hit the throttle at all, just turn the steering back and forth, you will see the rear end of the car lean back and forth, due to the front castor.

In general, on slick surfaces I do find that the 12 degree castor a-arms can cause severe oversteer on the M18, depending on the weight bias and stiffness of the suspension.

2 things you could do with the M18 is:

Switch the optional front a-arms that give it 6 degrees of castor. I've even experimented with using the rear upper a-arms on the front to give it zero degrees of caster.

Another thing that might help is finding a way to soften the suspension, and let out the down stops as much as possible, so the suspension can articulate more and soak up some of that wobbliness created by the castor, helping to keep all the wheels on the ground better.
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Old 02-27-2008, 03:47 AM
BustedRotor BustedRotor is offline
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I was looking through my gear, and I cannot seem to find the stock front A-arms. Where would you recommend that I get one? Thanks again for such a great feedback, it is greatly appreciated!!
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  #6  
Old 02-27-2008, 11:16 PM
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harnois harnois is offline
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The stock a-arms have 12-degrees of castor. They have a tendency to make the car oversteer when off-throttle but understeer when on-throttle.

You may want to try the "optional" a-arms which have 6 degrees of castor.

It should say on the arm which it is, between the shock joint and inside front pivot ball, it'll say 6, 12, or not have anything at all (which is the rear upper a-arms which have zero degrees of castor).

http://www.teamxray.com/xshop/produc...?kategoria=744

Here they have the 6-degree a-arms and also the adjustable tie-rods, which are also very helpful if you don't already have those.

Atomic also makes a-arms for the M18, but unfortunately I found that they were unusable because they had way too much friction in the ball joints.
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