tips for 56' Best Track race?

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davet
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tips for 56' Best Track race?

Post by davet »

Hello all. We're running a Council race June 7th and I just found out it's going to be a 56' Best Track. Any advice as far as weight placement or drift goes?
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Re: tips for 56' Best Track race?

Post by gpraceman »

davet wrote:Hello all. We're running a Council race June 7th and I just found out it's going to be a 56' Best Track. Any advice as far as weight placement or drift goes?
Are you sure that is correct? That would be a pretty unusual length for a Best Track.
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Re: tips for 56' Best Track race?

Post by TXDerbyDad »

gpraceman wrote:
davet wrote:Hello all. We're running a Council race June 7th and I just found out it's going to be a 56' Best Track. Any advice as far as weight placement or drift goes?
Are you sure that is correct? That would be a pretty unusual length for a Best Track.
It's not one they sell, but it is possible if you buy one of the flat extension pieces.

Generally, the longer the track, the more advantageous it becomes to shift your weight a little forward than on shorter tracks, but I have absolutely no personal evidence to back that up since we race on a 40 ft track.
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Re: tips for 56' Best Track race?

Post by FatSebastian »

TXDerbyDad wrote:Generally, the longer the track, the more advantageous it becomes to shift your weight a little forward than on shorter tracks
Why?
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Re: tips for 56' Best Track race?

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The guy supplying the track said its 56' Best Track with double stop section. Maybe that includes the double stop section.
Why would the longer track be better with a less aggressive COM? Does the Best Track have a level lower section or is it still a slight incline?
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Re: tips for 56' Best Track race?

Post by TXDerbyDad »

FatSebastian wrote:
TXDerbyDad wrote:Generally, the longer the track, the more advantageous it becomes to shift your weight a little forward than on shorter tracks
Why?
I couldn't begin to tell you why. It's one of those random "facts" I read on the Internet over the years of researching PWD. I didn't bookmark it and can't tell if it is true or not (hence my caveat in the post you quoted that I had no proof to back it up).
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Re: tips for 56' Best Track race?

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davet wrote:The guy supplying the track said its 56' Best Track with double stop section. Maybe that includes the double stop section.
Why would the longer track be better with a less aggressive COM? Does the Best Track have a level lower section or is it still a slight incline?
The stop sections on a BestTrack aren't 7ft long though; they're only 40" long. Only the flat sections of the track (starting ramp before the curve and the normal flat area after the track) are 7ft. Maybe they added an extra 7ft to the 26 degree starting section? If that's the case, then I don't think weight placement would matter over a 42 or 49 ft track. If he's got the double stop section, then I would be willing to bet that the extra 7ft is on the starting section before the curve/bend transition to the flat of the track. I've actually seen a video of a BestTrack setup that way before, so it's possible, and it too had a double stop section if I remember correctly. If it were just another 7ft to the flat of the track, I don't understand the need for a double stop section since an extra 7ft to travel would help work off more of the energy of the car.
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Re: tips for 56' Best Track race?

Post by davet »

I'll try to get more clarification.
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Re: tips for 56' Best Track race?

Post by ah8tk »

It is Warren's track (Mr. Slick), he used to use a 64' BestTrack but replaced it with the new 56'. Looks like he hasn't visited DerbyTalk since 2012.
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Re: tips for 56' Best Track race?

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ah8tk wrote:It is Warren's track (Mr. Slick), he used to use a 64' BestTrack but replaced it with the new 56'. Looks like he hasn't visited DerbyTalk since 2012.
Woah! What configuration was that in?
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Re: tips for 56' Best Track race?

Post by davet »

I just watched a vid of last yrs Council race at MOA. The fastest times were in the 3.65 range. Our fastest time at the District race was 4.04xx for track record on what I was told was a 46' track. That track couldn't have been 56' long with times in the 3.65 range could it? We might as well just stay home.

I'm wondering if a less aggressive COM on a long flat track is better because once the car comes off the incline the weight is more evenly distributed between front and rear wheels for the trip down the long flat. An aggressive COM would keep more weight on rear wheels down the long flat section but the weight isn't a factor anymore as its off the incline. This would mean more drag on rear wheels/axles during the long flat section.
Last edited by davet on Wed Apr 02, 2014 11:09 pm, edited 1 time in total.
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Re: tips for 56' Best Track race?

Post by Stan Pope »

Another explanation is that a less extreme CM requires much less DFW Toe-in to keep it on the straight and narrow. Less toe-in means less sliding friction by the DFW. Tracks with long flats reward lower friction.
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Re: tips for 56' Best Track race?

Post by FatSebastian »

Stan Pope wrote:a less extreme CM requires much less DFW Toe-in
This was my hypothesis. If so, would it not depend on how "extreme" the CoM was in the first place? That is, "the longer the track, the more advantageous it becomes to shift your weight" may not truly offer an "advantage" unless the CoM placement on the shorter track already required aggressive rail-riding.
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Re: tips for 56' Best Track race?

Post by Stan Pope »

FatSebastian wrote:
Stan Pope wrote:a less extreme CM requires much less DFW Toe-in
This was my hypothesis. If so, would it not depend on how "extreme" the CoM was in the first place? That is, "the longer the track, the more advantageous it becomes to shift your weight" may not truly offer an "advantage" unless the CoM placement on the shorter track already required aggressive rail-riding.
Yes, quite! Exact numbers are difficult, because of the variables.

On a short track, if you have a 1" CM on a wheelbase that is 1/4" shy of max, then only a slight toe-in does the job, e.g. around 1/2" in 3'. Back the CM down to 5/8" and a lot more toe-in is needed, e.g. 2 to 3" in 3'. On a short track, the 5/8" CM with more toe-in usually gives better times.

But that extra toe-in adds friction on the flat, and having a longer "coast" allows the extra friction to eat up the energy advantage of the 5/8" CM.

The better you do at making the car run smooth (very low run-outs, very well polished bores, etc) the less you need the toe-in to keep the car stable and optimize your times. These factors make "cookbook" numbers (like those above) "iffy", and make on-track tuning (on a track comparable to your competition track) important.
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