tkp
Pine Head
Posts: 65
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Post by tkp on Jan 15, 2009 12:12:29 GMT -6
All, Hope you are all well- looking for some quick advice. My son's pack and Council race is conducted on this track: www.supertimer.com/track/supertrack.htmlI'm confident that with no middle rail, he should at least lightly sand/smooth/graphite the outside of his wheels as it will most definitely hit the side of track many times. I was also wondering if a 3 wheeler will be stable enough on this type of Track if cog is somewhat aggressive- say 1 inch cog.- What do you think? Should he even attempt a 3 wheel config on this type of Track? If so, should we cant the back wheels to perhaps provide more stability? Additionally- what do you think about alignment on this type of Track- dead on or ?- say 1 inch every 4-5 feet? This track seems to be unforgiving on some cars weighted too heavy in the rear- ie 1 inch cog with a 3 wheel configuration. They have a tendency to slip, slide and shimmy or simply spin off if too aggressive. It is a fine line with this track. Anything else you think we should consider on weight, alignment, cog, wheels etc? My son's car this year is really shaping up thanks to all of your input in the past. Currently we have 3.5 oz of Tungsten at 1 inch cog. I believe we should be close to 3.75 of weight this year as the final weight we'll tweek during weigh-ins. He also will be using 1.8g wheels. Looking forward to your wisdom....and I will post a pic when complete. TKP |
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JustaDad
Addicted to Speed
1Cor 9:24
Posts: 79
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Post by JustaDad on Jan 15, 2009 13:33:05 GMT -6
I have never run on one of these tracks so please keep that in mind. After viewing the track it seems like you can run a car very low to the track. The lower you can get the weight be better off you will be. I would find out how high the finsh line sensor is and run as close to that as possible. I would think canting would be a huge benefit and lifting a wheel will still reduce friction.
Good Luck!
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tkp
Pine Head
Posts: 65
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Post by tkp on Jan 15, 2009 14:52:51 GMT -6
Thanks for the feedback....
I've scoured the net and did also find that this track lends itself to spin offs big time. I found a couple district posts thats state:
If you have your car too far rear weighted and a 3 wheeler (wheel too high), you may spin off the track. I found another post that indicated about 10% of the cars spun off. This track has too much margin- track width, and allows for cars to fishtail back and forth down the track.
We will move the cog to 1.5 inches and still attempt a 3 wheeler and will cant the axles as planned.
To make things even tougher, apparently the district track is the same, but they put it up higher-not the same as Pack! If we notice any concerning shimmy down the track at Pack, we will have to move the cog further up for Districts.....geez.
Additionally it seems the stopping mechanism is a "foam type well" and not very deep and cars constantly bounce out of it and get damaged and even hit each other.
My son's car is very thin and weight is very low and centralized so this may help as JustaDad indicated.
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Post by andylester on Jan 16, 2009 1:52:03 GMT -6
All I can say, is GOOD LUCK! Those tracks are so unpredictable that the best car usually does not win. If your car is fast and is winning, the crash up garage at the end will put the stop to your fun. I have seen cars jump lanes only to crash into the back of another in the crash garage. Not a pretty site, especially if you have any time & money invested in your baby,...I mean your son's car! The longer the wheel base the better on those tracks. Because they are so wide, I have seen short wheel base cars turn sideways and get stuck on their lanes. Wish for the best.....that is about all you can do this side of making a car that is about an inch wider and longer! Thanks Andy Lester Florence, KY www.mpp-models.com |
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JustaDad
Addicted to Speed
1Cor 9:24
Posts: 79
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Post by JustaDad on Jan 16, 2009 10:18:52 GMT -6
All I can say, is GOOD LUCK! Those tracks are so unpredictable that the best car usually does not win. If your car is fast and is winning, the crash up garage at the end will put the stop to your fun. I have seen cars jump lanes only to crash into the back of another in the crash garage. Not a pretty site, especially if you have any time & money invested in your baby,...I mean your son's car! The longer the wheel base the better on those tracks. Because they are so wide, I have seen short wheel base cars turn sideways and get stuck on their lanes. Wish for the best.....that is about all you can do this side of making a car that is about an inch wider and longer! I think Andy is on to something. What if you used "curb feelers" to widen the car? You could use push pins with polished and graphited heads. They would hit the sides first and my prevent excess sliding. I would place them in front of the front wheels and behind the rear wheels. Or you may just want to widen your car with some balsa wood to protect the wheels and alignment in the crash up derby garage. I remember someone making a wide car on the board but can't remember who. You should look for it, you might get some good ideas. The other issue that is a true dilemma is the weight location. I feel the lower the better. But having your weight in the back is going to make it want to pass up the lighter front especially when you have a little resistance from the front hitting the side of the track. The problem Porsche has been working on for years. They get out of it with wheel braking traction control and on and on. You don't have anything but gravity to assist you. Weight evenly distributed may produce the most stable car. Unfortunately testing is required to prove out theories. I would get a cheap full length door mirror or Plexiglas, stick some bumpers on it, to make a lane in the exact width and make a test mule car that you can easily move the weight around on and play with different set-ups. I fear Andy is right and the best car may not win just the luckiest car. Good Luck!! |
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Post by kcbcommando on Jan 17, 2009 7:49:56 GMT -6
I had one of these at my church for 3 years. Here's what I found: Make it as wide as possible make sure the outside of your wheels is smooth as they bump into the rail often. Go for as perfect alignment as you can get. The track is not "flat" but crowned, and it varies in different places. If they haven't scrapped the "crash garage" you may wish to add some "fenders" or a stout wing (like the front of a Formula 1 car) to the front to protect it a bit. Just make sure it doesn't hit the sides of the track. I scrapped that and got some memory foam from a mattress builder- no problems works great. I wouldn't get crazy with the graphite on the outside of the wheel. Just smooth it. I did experiment with running the wheels inside out- If that's the only track you use it might work, if not don't try it. Given the fact that your car will contact both sides you may wish to have all 4 on the track so you don't have a non spinning wheel hitting the side of the track. If you do decide to steer it to one side maybe doing the opposite of a rail rider and make the rear quite narrow? Sounds like some experimenting is in the works!!! Our cars did well with a dead on alignment, since my track wasn't used at regional competition we weren't as fast there but we still placed. If you can narrow your tread I would do that, lighter wheels may offset having 4 on the track. Don't forget your car has to pass over the triangle thing with the sensor tab on it. If you are narrow and steer to a side you may hit it with a wheel and not have it go under the car. Give me a pm if you need more intel than I've got here. Don't do COG super aggressive, go 1" or very close, you have LOTS of flat land to run on unless they have modified the slope. My first season my cars were too light in the nose.  If you can give me a pic of both tracks I can give you some guidance with weight placement. |
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tkp
Pine Head
Posts: 65
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Post by tkp on Jan 17, 2009 10:21:58 GMT -6
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Post by kcbcommando on Jan 19, 2009 14:24:03 GMT -6
Standard layout. lots of time on the flat portion of the track and super steep. you can move your COG forward a bit, that will be fine. Slightly forward of normal will give you better speed on the flat portion. I didn't cant because my wheels taper from the inside (body) to the outside. I wouldn't do it to aggressive, maybe 2*
I tried 1 three wheeler, I didn't notice a substantial benefit. Our rules at the time let us narrow the wheels so mine were 1/8" and I think that definitely helped with the speed aspect. Also the outside of the wheel was sanded smooth (AWANA GRAND PRIX was on the outside) to make hitting the sides less damaging.
Shhh- I would place a small piece of wood under the extreme front of the car so it's lower to the track by a few thousands. Might help you trip that sensor tab thing .0000001 quicker. The blue triangle that holds the sensor is about 1/16" iirc.
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