Testing your car on a guided track,when racing on a lane track

Secrets, tips, tools, design considerations, materials, the "science" behind it all, and other topics related to building the cars and semi-trucks.
MJThurston
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Re: Testing your car on a guided track,when racing on a lane track

Post by MJThurston » Fri Apr 13, 2018 6:46 pm

So I'm getting the car do go down the 8 foot long tuning board without hitting the side but when I take it the 32 foot practice track the back end is moving back and forth.



MJThurston
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Re: Testing your car on a guided track,when racing on a lane track

Post by MJThurston » Fri Apr 13, 2018 7:09 pm

Car 1. Back /---\ Front [---/ Best time 2.420 but can't get back to it.
Car 2. Back |---| Front [---/ Best time 2.401. Ran it twice more 2.403, 2.401, 2.403.

Difference
Car 1 2.5 degree on back, 1.5 on front, raised NDFW
Car 2 no bends in the back, 1.5 on front, raised NDFW

Thinking of getting 2 straight axles for Car 1 to replace back.



Speedster
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Re: Testing your car on a guided track,when racing on a lane track

Post by Speedster » Sat Apr 14, 2018 9:47 am

MJ, I think we're dealing with too many things at once. Going back to your Topic. Testing a car on a Center guided track is not what you want to do on a lane track. There would be no reason to narrow the car body 1/16" behind the Dfw if you are running on a lane track. Your 2 cars are different in every way even if they look alike. Concentrate on one car. Your goal is to make a car go down a Lane track as fast as you can. At this point I can see you have 2 choices. 1. You can set up a car to run as straight as possible and hope for the Best. 2. You can steer the car into ( let's say the right side) the right side and keep all wheels other then the Dfw from touching anything. Your fastest car has an advantage no matter where the advantage is located. You might want to take that car and set the Dfw with Negative camber (Your choice on amount) and slight toe out. That should take the car to the right rail. If the right rear wheel does not stay off the rail then set the right rear wheel with a little toe in and run it again. That will put the wheel up against the wood block and farther away from the rail. If that doesn't work set the left rear wheel with a little toe out and try it again. At some point the right rear wheel should stay off the rail.



MJThurston
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Re: Testing your car on a guided track,when racing on a lane track

Post by MJThurston » Sat Apr 14, 2018 3:35 pm

I'll do some more tinkering tomorrow. Burned out right now. My son's derby day isn't until the 28th of April.



MJThurston
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Re: Testing your car on a guided track,when racing on a lane track

Post by MJThurston » Mon Apr 16, 2018 7:09 am

I am confused why my 3 wheeled car with only one wheel at an angle is out performing my 3 wheeled car with 3 wheels angled.

I have my tuning board level but can not seem to get the cars to touch the side of the rail at the end of th 8 foot board. I get can get the cars to go left or right but the variable I turn at doesn't give me very good results.

Example - move the axle to the right slightly and I go into the left rail, then turn it slightly left and it goes into the right rail. Seems like I can't find even a close sweet spot.



Speedster
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Re: Testing your car on a guided track,when racing on a lane track

Post by Speedster » Mon Apr 16, 2018 10:14 am

MJ, to answer your 1st question. The Laws of Physics were followed more closely by the faster car whether it was intentional or by accident.

I have a 3 wheel rail rider, left front wheel raised, back wheels set at 1 1/2 degrees Negative camber. Both back wheels migrate to axle heads while rolling the car forward and backward. Right front wheel set at 1 1/2 degrees Positive camber and toe in.

This is how the car is presently set up:
Left front wheel is raised.
Dfw (Right front wheel) set with Negative camber and toe-out. Very, very little toe-out.
Right rear wheel set with Positive camber and toe-in. Very, very, very little toe-in.
Left rear wheel remains same as original set-up.

The car steers into the right side rail and the right rear wheel clears the rail by about 1/16". The car runs very straight and smooth. I kept adjusting the right side wheels to set the car with the least toe necessary. The lettering on the dfw does ride on my side strip which is about 1/8" high. I think if you graphite the side letters well it should last for the race. I also think this car will be faster then a car set up to run straight because those cars are probably going to drift and then both side wheels are going to be dragging down the track. The builders might not graphite the lettering which will cause their cars to increase friction.
Please check your email.
Cheers,
Speedster



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