Should I mess with this...

[TwoRacers]

We built two 3 wheel cars this year. One using a bent front axle to bring the dom front right wheel to the rail, the other with no bent axle. The bent axle car is now (after some tuning for the wood warping) running eqal to our undefeated council champ car from last year. The second car (without the bent axle) is ever so slightly even faster than the other two cars but it is actually drifting 1" in 4 ft to the RAISED wheel. So, do we try to reverse the drift to the dom wheel or do we let the car run as is since it appears to be competitive relative to our council champ for last year?

Of course, last years car may be running slower (we dont have a timer) and we just dont know it although it has been stored safely. All testing is done on a 5ft shelf board with latice strips that we have raised from a few inches to up to 2 feet to see how the cars start.

Thanks in advance for the help.

TR

[BlackLotus]

Just for clarification. If I read correctly, you are not running the cars on a track, just a 5' board with an incline. Using the board, without a center guide strip, the car in question is the fastest of the three cars mentioned on the straight incline of the 5' board?

If that is the case, I would try to "fix" the car so the dom. wheel rides the rail. The theory is based on the dom. wheel, and only the dom. wheel, riding the rail to reduce the friction of multiple wheels hitting or of the raised wheel hitting and having to start spinning.

[TwoRacers]

Sorry for the poor sentence structure. The testing is being done on a 5ft board WITH a center guide strip made of lattice which is comparable to a normal center strip.

[PWD_addict]

How can you tell which car is ever so slightly faster?

[TwoRacers]

I raced them side by side. Granted its only over 5ft but it seemed consistent over that span.

[crackerjack]

You need a track to test with, 5-ft is not enough to give you the info you need to know except how straight or how much turn you might need to ride the rail.

[PWD_addict]

You need a track to test with, 5-ft is not enough to give you the info you need to know except how straight or how much turn you might need to ride the rail.

I've seen it happen that a car pass another car in the last 3 feet of our 48 foot track. I wouldn't consider either car faster based on a 5 foot run.

[priority]

Let's take a look at what testing on the 5' inclined plane does and does not reveal:

Does:
1. Qualitative comparison of the bore/axle polishing on the cars.
With only a few inches drop, and assuming all the wheels on all the cars are the same and graphite is the lube, the car that is first to the bottom has a lower coefficient of friction. Aerodynamic drag is very low at low speeds, so bore/axle friction should be the dominant slowing force present. So, the winning car should have less friction.

Does not:
2. Which car will be faster on an actual track.
Aerodynamic drag and COM effect are missing from the inclined plane test. Some cars have the dreaded shimmy at full speed. And dozens of other things are different at full speed.

3. How good your RR drift is going to perform.
Once again, there is not enough in this test to even hazard a guess. I am a firm believer that you must test and tune a RR on a full-size track to maximize speed.

4. How good last year's council winner still is today.
Wood can warp. Metal can oxidize. Moisture gets into stuff and messes it up. Dust can get into the wheel bore. Little sisters can drop the prized car and not tell anyone..... There are an unlimited number things that can slow a car and many of them are not easy to detect without a full size track with a timer.