Gizmodo Takes on Pinewood Racing

[Kinser Racing]

Nice review 5Kids! I don't know what it is but I can't even watch videos like that, it sounds like Charlie Browns teacher. (Not Kinsers teacher! lol)

They're just totally boring!

 

[Spirit Racing]

5kids you have nailed it dead right again. Great review !!! Does your wife think your right all the time ??

...

....SPIRIT.....

 

[5KidsRacing]

5kids you have nailed it dead right again. Great review !!! Does your wife think your right all the time ??

...

....SPIRIT.....

Not so much......

 

[bracketracer]

Good video, but one thing I find way out of whack is a car with graphite will beat a car with no graphite by less than one car length???? I find this hard to believe.
2 years ago at my kids' school, one dad entered a couple cars, they did not have graphite and they came up about 5 feet short of the finish line. Half way through the races when we were on lunch break, I put graphite in the bores for him. Let me tell you, those cars not only finished after that, they were actually some of the faster cars.

+1. We had a boy race a car last year at the Pack's test & tune night with no graphite. He was easily three or four feet behind the other cars at the finish on a 28' track.

 

[DerbyDad4Hire]

Good point on the graphite. Another miss.

As far as rail riding goes, when derby worx is dumb enough to say they invented it then they must be slayed over and over. The rail riding tool is one of the biggest jokes in PWD history and is one of the worst tips you can tell the majority of new PWD racers. If Derby WOrx was brand new and came out with all that stuff everyone would be slaying them but now everyone has to be politically correct. I am too much of a jerk to be PC!

 

[GravityX]

Great review of the video Scott.

Now to get that link posted on Facebook to rebuke the video. Question though... what is Facebook? /images/boards/smilies/smile.gif

 

[txchemist]

Just a few points-

I need to find time to see the full "Science-guy" video, but I can tell you he did something super wrong and got himself all messed up. Archimedes would set him straight.

Really!

I will just poke him on weight placement and graphite. I show two sets of tests on weight in the back vs. weight in the front. one set with good lube, and the next set with bad or no lube-
NO WAY to get such a change if this is the only variable changed, so his problem was stupidity and laziness. He has a car WAY out of alignment and as you find improvements, you should go back and revue earlier tests to make sure you found the right things. If your car is in alignment, weight placement is worth less than 1.5 car lengths, and cruddy graphite will drop the friction on steel and polypropylene down from 0.3 to the 0.12 range- a GOOD graphite process will go much lower, and average graphite is worth almost 2.5 car lengths so his least important variable is actually the most important variable ONCE you can make a car with good alignment.

Based on such poor science, I call SHENANIGANS!

 

[GravityX]

Txchemist... I was wondering if you would chime in on this, I knew we could count on some numbers from you.

 

[IAE Racing]

I'm surprised the "science" differs that much.

 

[txchemist]

Notice I did not say he fibbed, I'm sure he got those results, he just did not realize that alignment was that critical. If he stopped and put some of his data into Excel and worked out what gravity must have been to get such slow results, he would have discovered something is wrong. If your car is SO out of alignment that graphite has little effect, I would tell the student to go away until he can explain the results. Imagine a car crabbing down the track if the COG is near the front wheel. It improves when COG is moved to the back wheel. BUT it improves beyond the actual expected change in potential energy- that is where he went to la-la land.

 

[ngyoung]

You should post that in the comments section for the video. I've already spammed it with a couple digs about what he got wrong. I linked 5kids review in there as well.

Just a few points-

I need to find time to see the full "Science-guy" video, but I can tell you he did something super wrong and got himself all messed up. Archimedes would set him straight.

Really!

I will just poke him on weight placement and graphite. I show two sets of tests on weight in the back vs. weight in the front. one set with good lube, and the next set with bad or no lube-
NO WAY to get such a change if this is the only variable changed, so his problem was stupidity and laziness. He has a car WAY out of alignment and as you find improvements, you should go back and revue earlier tests to make sure you found the right things. If your car is in alignment, weight placement is worth less than 1.5 car lengths, and cruddy graphite will drop the friction on steel and polypropylene down from 0.3 to the 0.12 range- a GOOD graphite process will go much lower, and average graphite is worth almost 2.5 car lengths so his least important variable is actually the most important variable ONCE you can make a car with good alignment.

Based on such poor science, I call SHENANIGANS!

 

[txchemist]

OK, I think I see the problem. The science guy is not too far off, but Shamwow has misspoken about what was done. The actual sequence of steps was
A. bring the car up to 5 oz. and then
B. where should you put the weight?

the answer was, A add weight to car that is light and has COG in the middle.
improvement = 4 car lengths.
COG still in the middle.

now move the weight to the front, drops the advantage to 3.4 car lengths.
Move weight to the back- improves to 4.6 car lengths. ( so the real effect of COG is 1.2 car lengths as we normally conclude)
So when you combine both A and B you get the effect of adding correct weight to the back of the car= 4.6 car lengths. When Shamwow puts both together and attributes all the speed gain to putting the weight in the back, it is true, but not really COG only as inferred with 1. center of mass location statement.

 

[ChrisF]

Who is "Shamwow"?

 

[3phase]

 

[DerbyDad4Hire]

Who can tell me why the car slowed so much with the weight in front?

 

[down4derby]

Who can tell me why the car slowed so much with the weight in front?[/QUOTE not as much potential energy?

 

[kpendle]

Who can tell me why the car slowed so much with the weight in front?

My guess/answer would be a 3 wheeled car with all the weight up front is not going to ride on the correct 3 wheels. It would be all screwed up if built as a standard 3 wheel design.

 

[Papa V Racing]

Well Said 5Kids-

You're always on it..

Want to really know how to go fast?

Click the link below, sign up, read, ask questions & go fast!

Love THIS!!!!

 

[Papa V Racing]

Who can tell me why the car slowed so much with the weight in front?

Weight behind the axles and just in front as we run has the weight lower center of gravity. The weight pushes the car from the top to the transitions where and continues to gain speed more then car weighted in front pulls it down to the transition and the car has no more pull when it get to the flat after transition... so it can't gain any speed...

I don't think I explained it the way it should be...

 

[txchemist]

OK, I was able to freeze and check some of the charts from the science guy Scott Acton- He only shows moving the COG from 1" in front of the back axle to 2.5" in front of back axle. That was his definition of weight in the front and that time was 2.54 sec. while weight in the back was 2.52 sec. Just at 0.5 car length difference. So the fake animation of the red and blue car showing the weight in the back red car winning by over a car length is an exaggeration of his own data.
so more accurate to say- add weight to 5 oz equals a 4.35 car length advantage. ( as Scott shows but Mark misspeaks) Move it to the back, 4.6 car L advantage- move it to the front is 4.10 car L advantage. The reason his data is less than a car length is he is restricting the design to slots in the car instead of allowing an extended base as I used for first guess.