"Weight is important, but it isn't everything"...???

[TOU]

in a recent thread Stan wrote:

Weight is important, but it isn't everything.

Until recently I didn't think weight was completely everything...but pretty dang important. However recently some things have me really rethinking this a bit....as to exactly how important weight really is; I think Stan is dead on. Maybe...just maybe it isn't nearly as important as I had once thought. Yes I know...if everything down the line is completely equal, it probably is...BUT "everything" is NEVER equal.

Anyway...this past weekend, we had our 5th annual unlimited race at our church. This year we had two classes...an 8 oz Class & 5 oz class. We did fairly well overall and had a ball (I even built a prop type car that I made into more of an exhibition type rig.) So last night I started looking at the numbers from each class...then I meshed the two classes to see how much faster the 8 oz class cars were compared to the 5 oz cars. I would have thought the 8 oz class would have totally dominated the 5 ouncers...they didn't. Some of them did well but several of the 5 ouncers kicked some serious tail...including my daughter who won overall Grand Champ. So...I posted the top 25 cars numbers (of nearly 70 total) for you to look at. See what you think...I thought it was kinda interesting.

Place_@Time____@Speed__Car #__Wt.
__________________________________________________________
1____3.0050_____226.9____26____5____My 14 yo daughter
2____3.0347_____224.7____56____8
3____3.0627_____222.6____77____8____My 17 yo daughter
4____3.0700_____222.1____30____5
5____3.0763_____221.6____72____5____My Wife
6____3.0953_____220.3____34____8
7____3.1127_____219.0____47____8
8____3.1293_____217.9____51____5
9____3.1443_____216.8____98____5
10___3.1450_____216.8____60____8
11___3.1477_____216.6____75____5
12___3.1500_____216.5____24____5____My 8 yo son
13___3.1577_____215.9____44____8
14___3.1603_____215.7____71____8
15___3.1627_____215.6____42____8
16___3.1638_____215.5____45____8
17___3.1723_____214.9____76____5____My 6 yo son
18___3.1790_____214.5____85____5
19___3.1850_____214.1____33____8
20___3.1860_____214.0____23____5____My 11 yo son
21___3.1870_____213.9____10____5
22___3.1970_____213.3____73____5
23___3.2113_____212.3____43____8
24___3.2167_____212.0____48____8
25___3.2290_____211.2____21____8

[Stan Pope]

Good stuff! Thanks for posting it!

My guess is that the 8 ouncer's tended to be overrepresented in the top 25 and underrepresented in the bottom 25, just because the extra weight gives some edge and allows a bit less care in other factors. (There may be other factors, like "8 ounce builders are more experienced". Anyway, you can look at the list and tell me if I'm right or "out in left field.") The 8 ounce builder can still "shoot himself in the foot" by doing less well on alignment, lubrication, weight distribution. And he can do less well on wheel rotational inertia and aerodynamics because they saps a smaller percentage of his total energy.

[TOU]

I'll try to address several of your points tomorrow as I'm beat, but thought I would point out a couple more statistics from the data above before I hit the sack. 12/25 of the overall top cars were 5 ouncers...including 1st place. Additionally 5/10 of top 10 are 5 ouncers. Wild eh?!

[Nitro Dan]

I think they've discussed this before in a number of thread here at DT. Here's one I found that sort of sums it up for everyone:

viewtopic.php?f=11&t=4738&hilit=Weight+Heavy+Car" target="_blank

-Nitro Dan

[Rod Turnbull]

Quick question... if you added all the weight to the wheels would the beating your took off the starting line be less than the beating you took because of the extra friction?

[sporty]

Weight isn't important, but isn't everything.


Certainly, just adding weight or more of it, is not going to ensure a faster car !

To many other factors at work here !

Weight placement, wheel and axle prep. type of track ! alignment.

While looking at the times, just don't forget without all the builder data from the builders. Then the data is not as promising as one might think.

Sporty

[Go Bubba Go]

Quick question... if you added all the weight to the wheels would the beating your took off the starting line be less than the beating you took because of the extra friction?

From what I've seen you'd get a grade A whoopin' on a "normal" length track.

You'd get off to a REAL slow start, and while the other car is going to be slowing down faster (slowing faster? ) due to the increased bore-axle friction, you just don't have enough track to overtake them before the finish line.

Consider all the controversy about the use of lightened (1g or 2.2g) instead of stock (3.6g) wheels in Cub Scout races. Now consider that you'd be comparing 3.6g wheels to potentially 30+g wheels.

Bubba

p.s. BTW one complication is that the 30+g per wheel assumes the wheels are evenly weighted, and with the wheels in a typical configuration (i.e. two wheels near the front of the car and two near the rear) would result in a COG nearer the middle of the car than most winning builds. I suppose you could put nearly all the weight in the rear wheels, but then you're talking about nearly 60g per wheel - SLOOOOOOOOOOOOW.