How you know...

[Wingman]

...if your cars are ready to race?

Without a test track, what can you do beyond low-angle rolling and aligment tests?

Thanks for your thoughts,

Ken

[joe]

You build a test track when your wife goes out of town for that long weekend!

[Wingman]

Well...I did pick up a couple of 11' lengths of vinyl siding soffit. This makes a very simple, low cost test track (<$30). It differs from the usual track in that it guides from the outside rather than between the wheels. Also, and most importantly, the "lanes" have a very slight crown, causing the cars to end up against one rail or the other and stay there. Clearly, this is less than perfect. At the same time, I've run last years cars on it, and they finish with the same relative spaceing.

I'm wondering if anyone else has played with this soffiting and how well it predicted performance on a more official track.

(I will say that our den had a blast playing with it, particularly since its easy to make jumps in track!)

Ken

[Teeeman]

They have the "test tracks" made of extruded plastic at the Scout store locally, my son wanted it, I said "no"...


would 2 $10/ea. test tracks such as this be useful in evaluating cars?

(or would it be so crude the results would be unusable)?


-Terry

[Stan Pope]

"Test" tracks attempt to predict race outcomes, thus allowing adjustments, by mimicing the real track. Invariably, some parameters are excluded or, at best, simulated quite crudely.

To produce good results, the test track should only be used to make adjustments in parameters which the test track simulates accurately.

The task of selecting a test track is made more difficult if you don't know anything about the real track until race day! For instance, how well the car holds its line at speed depends a lot on the specific real track ... its geometry and its surface. I can't afford, and don't have space, to replicate the likely racing environments!

So, I approach the test track issue by using a mini-track that isolates and magnifies important variables that are difficult to "design in." My focus is on tread surface consistency and on axle alignment. My "test track" is one end of my wooden kitchen table.

[Pinewood Daddy]

They have the "test tracks" made of extruded plastic at the Scout store locally...

would 2 $10/ea. test tracks such as this be useful in evaluating cars?

The results couldn't possible be compared to a real track. Especially if you're tuning an already fast car. Every track is a little different (wood vs. aluminum, surface roughness, track joints, track not level, etc.). Even the same track can have different times when setup at another time (I know that from personal experience).

[Teeeman]

I was just thinking to use the track to compare to last year's car...

only an "apples to apples" comparison...


I gandered to say the imperfections in such an extruded track would be bad enough to make even side/side comparison meaningless...


?


-Terry

[Wingman]

With my vinyl soffit based track, even though there's crown accross the lanes of about an 1/8", improving a cars alignment has noticable improved that car's performance relative to a basline car. I think, even though its not tracking freely on average it is slipping less and this shows up at the finish line.

Ken