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Post by aircooled on Jul 28, 2011 12:12:47 GMT -7
We have a 35' Best Track and I have a question about time to shoot for. Is there a way to figure what time we need shoot for to be competitive on the PDDR track? What is a fast time for a 35' track?
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Post by DNA RACING on Jul 28, 2011 13:55:25 GMT -7
i wish i could tell ya, but there are just too many variables involved. i have a 42' best track and even if i set the angle the same as the league track and make sure its totaly flat and level my times are different . that and even the timers will read different. as a very loose rule of thumb if you can average out to under half a second per 7 feet of track you should be doing ok.?. that was with my setup, results vary. bri
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Post by txchemist on Jul 28, 2011 15:00:44 GMT -7
Here are tests Glenn ran before the new timer chip, so you need to know if you have the new chip if you have micro wizard. assuming you have the same angle and track preparation, the needle car time is now about 0.065 slower. Use the needle car time and assume a 0.04 mu for friction to set up your calculations. My calculations for PS would say the top time on a 35 Ft set up exactly like PDDR would be 2.515 sec. on my track set up it would run 2.5486 I will know for sure after next Sat. because I will send in a car which is the best way to find out. Present times for needle Cash Racing- 2.898 Mirror Image- 2.898 tie for first Goat Boy Racing- 2.899 From Glen earlier: I HAVE THE PDDR TRACK SET UP AT A 35 FOOT RIGHT NOW... the times for a pure stock car are at 2.45's - 2.46's (remember- older chip and not laser start) i put ZO7 on the track to see what it would do WHICH IS A NEEDLE CAR WITH THE HOLESHOT XS2'S WITH TEFLON INSERTS ON OIL WHICH RAN A 2.835 FASTEST TIME ON THE 42 FOOT SET UP... ON THE 35 FOOT SET UP IT RAN 2.400 3 in a row..
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Post by DNA RACING on Jul 28, 2011 16:01:58 GMT -7
that my friend is a pinewood fact. ;D
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Post by txchemist on Jul 29, 2011 9:06:24 GMT -7
I think the track as it is now may not be 27.1 degrees at all. More like 26.77.. but that is just using a math equation that can't help. By the way, 26.77 degrees would predict a 0.045 mu for the needle record and a 0.046 mu for the PS record. If the track is really up at 27.1 degrees still, then mu for needle car would be 0.18 and 0.075 mu for PS. I think we can see the problem with that.
Height of track to center of car... angle 45.61 ________ 26.7 45.77 ________ 26.8 45.93 ________ 26.9 46.08 ________ 27 46.24 ________ 27.1
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Post by DNA RACING on Jul 29, 2011 13:54:25 GMT -7
dont mean to sound dumb( it fits, just ask my wife ;D)but what the heck is mu?
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Post by txchemist on Jul 29, 2011 14:22:44 GMT -7
mu = μ Coefficient of friction
teflon can get as low as 0.04
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