NASCAR Ovals

[WesR]

I am finding that designing a Magracing oval or D track which maintains the level of driving interest that we are used to is surprisingly difficult. In full size oval racing, the driving skill is largely needed to handle the heavy traffic. I guess that in practice on an full size empty track, the perfect racing lap would only require the steering to be turned left twice and the brakes only applied twice but, with 40 or so other cars on the track, obviously there is much more to think about. I am assuming that the same will apply to our Magracing tracks. I myself have driven thousands of oval laps with
r/c electric and i.c. cars and we always needed 5 or 6 cars racing to make things really interesting.
I keep having a few laps round the new track in between track modifications in an effort to anticipate what will happen in a race, but it's not easy.
The track was built with 3 lanes but I am not sure now and have converted one into the pit lane. I reckon that one lane change only could be enough. With a number of cars running, lots of lane changing could be disaster.
At the moment we have racing line l/cs on one turn only (this is the Martinsville style
turn which does have a racing line) but this dosen't give the driver much to do.
Until we get 6 cars running and some race experience, we won't really know

[goatdope]

Good news ! I have recently completed construction of a modular 1/4 mile motordrome. This is my first track so I used a different method of laying the wire to be easier to make changes. Using a mini circular saw to cut a .035 in. groove then merely covering the exposed wire with cellophane tape. I was truly astonished to see how good the two rolling chassis ran. Therefore, I simply gave the whole thing two coats of latex grey primer. Also, a corrugated paper retaining wall was fashioned to keep the cars on the track. As for realism, the cars both lap in the 8 second range, which is only 50% faster than full scale ! Banking is only 5 degrees all the way around and the turns are 48 in radius. Each module contains a half straight and a half turn, being cut from a 4x8 sheet of sanded plywood. There is no flat out on this track, the cars spin out readily both going into the turns and out if the speed is too great. Although there is two lanes, the racing line uses the both lanes. Inside on the turns and drifting to the outside lane under acceleration. One need not worry about changing lanes until catching a slower car. There is only 4 lane change options while racing, plus 1 for entrance to the pits which is at the very end of the track. Seriously, I am a man of average mind and skill , Lady Luck had a lot to do with the success of this track. I hope the longer wheelbase chassis are available, the sight of 16 stockers blasting around this track all at once should be a sight !


!

[Lasp]

Very good description goatdope!
Moore of this, and pictures ofcourse .

I realt like your comparing with the real time race. Thanks from Lasp

[goatdope]

Very good description goatdope!
Moore of this, and pictures ofcourse .

I realt like your comparing with the real time race. Thanks from Lasp

Hi Lasp, I just finished completing the infield portion last night. Having trouble finding late 60's bodies in 1/32 scale. young son is the photo/ video person. As soon as we can get 5 or more cars looking like real stockcars , there will be a video.

[goatdope]

Hi There, While waiting for more equipment to arrive, did some testing on the two stock cars that I cobbled together. One is a Dodge Avenger Bobby LaBonte NASCAR that I got online for $10 , the other is a 69 Mustang , both hard plastic. Got real frustrated trying to mount the bodies with screws. Finally resorted to using a measured thickness of celluloid packaging material between the body and chassis, then fastening with cellophane tape. Tested both cars on my 1/4 mile motordrome with progressive higher weight. Lap times surprisingly went down as the weight increased to about 3.5 oz. I had to remove the tape on the tires to slow them down . However, at 4.5 oz. the cars really slowed down to the point that you were running "flatout". At 3.5 oz. the action of the cars seems most realistic. Also discovered that if the extra weight is in the front, lane changing is more predictable. If the weight is all in the rear, acceleration is better but at the cost of lane change precision. Got bored one evening and decided to test the endurance of the trustfire batteries. I would have been satisfied with 50 laps and was happy to get to 100. I was absolutely astonished to reach 200 laps. This was running hot laps, not cruising around at a constant speed. Using only the speed control to save power, steering only to get back on the "groove" after spinning out a half dozen times, around and around the Dodge went. I almost fell off my stool when we reached 300 laps and continued on to see when the battery would run out. I gave up at 330 laps with the car starting to show some sluggishness but still able to spin out in the turns !!! I took a little break, then ran the Mustang a full 300 laps !! The track that I modeled my oval on, Raceway Park, Blue Island, ran 30, 50, 100 lap feature races during the regular season. The last race of the year was called "The 300 Classic " !

[Nor Cal Mike]

Your experimenting with weight is interesting. Were you able to achieve the optimum 3.5 oz. weight with a hard body? I assume no interior was used or perhaps with a vacuformed interior tray? I have some old black windowed Scalelextric Nascar bodies here that might be good candidates for a stretched magsteer chassis.

Mike

[goatdope]

Yeah mike, The weight with both plastic bodies mounted is just over 3oz. Had to add 1-2 pennies to reach the 3.5 weight. I have since switched to clear plastic / lexan bodies which are "feather light" and had to add 12 pennies to reach the "magic" 3.5 oz. !! There is a benefit because with all those pennies, you now can move the weight around to get the best performance. This is what they do in real stock cars, except you grab a wrench and adjust the "jack screw" on the spring you want to load or unload. The plastic bodies look great, I had trouble finding 67-72 Chevelle 1/32 scale bodies which is why I switched.

[Nor Cal Mike]

Good to know about the bodies. Need to look into building a highly portable oval. Slot car tracks fill all of my available permanent space. A mag track that can be set up outdoors on saw horses and light enough to be picked up and carried by myself would be ideal.

[WesR]

Progress with the track has been slow. The new slightly heavier cars and faster lap speeds produced an increase in the steering shimmy or fishtailing problem This in
turn made the lane changers less reliable. This has now been solved by replacing
some of the .028" wire with .036", mostly on the straights leading up to the l/cs.
Also by sanding the track surface down to the wire. This problem was partly brought
about be using dry 1/8" hardboard which has buckled with the winter damp.
We reduced the wire down to .028" to make it easier for cars to run across it when
being driven back onto the track but perhaps my worries were unfounded as the
cars still run across the heavier wire ok.
In hindsight now I feel that perhaps .036" wire would give more consistent driving
and lane changing and that perhaps we should recommend this instead.
Also changed my mind several times on track design. Originally we had 3 lanes
but, after watching many Nascar videos, most racing seems in one or two lanes and
also lap counting is easier with two lanes so the inner lane is now basically the pit
entry and exit. Lane changes have been reduced to 2 only with just one racing
line and the pit entry. The track is now very simple and the idea is to do some racing
first, see how it goes and pehaps add l/c and racing lines later. Very difficult to
forcast how 6 or more cars will run. Scenery is difficult with such tracks but, as you can see, we are making some progress.

[WesR]

Lets hope all these spectators buy a car!

Spectators april10 006 (640x346).jpg (215.19 KiB) Viewed 14355 times