Race review and question

[AUPatrick]

In getting ready for this years Pinewood Derby race I went back and reviewed the District Race Video that I took from last years race to get his times for comparison purposes. In the finals, my sons car (which came in first) went head to head with the car that ultimately came in second on three of the four races.

In watching the video in "slow mo" the other car (in all three races) was immediately ahead in the initial drop and it wasn't until close to the end of the track that my sons car caught up.

What, if anything did we do wrong, that would account for him getting such a quick advantage at the beginning of the race? Thank goodness the track was 42 feet long because if it were 35 I think he would have beaten my sons car.

Anyway, just wondering if anyone has any insights that you could share.

 

[Crash Enburn]

My first thought is that he had lighter wheels. Dunno...

 

[pony express]

It could be you had a better dynamic lube compared to the competitor and he had a better static lube like graphite versus oil. I think graphite beats you off the line and the oil will overtake them on the straights. Any other thoughts?

 

[Quicktimederby]

That's what it sounds like to me.

My first thought is that he had lighter wheels. Dunno...

 

[Kinser Racing]

It could have been lighter wheels. Was the other car a railrunner? You could have had a little to much steer in your car. It really could be several different things but those are the most likely culprits IMO.

 

[AUPatrick]

Our car was running graphite and I assume his was as well. I had 4 1/2 inch over 4 feet of steer. I don't know if he was rail riding but i never saw any wobble so he might have been.

I didn't know that lighter wheels gave you a quicker start. That's good to know.

 

[Kinser Racing]

Our car was running graphite and I assume his was as well. I had 4 1/2 inch over 4 feet of steer. I don't know if he was rail riding but i never saw any wobble so he might have been. I didn't know that lighter wheels gave you a quicker start. That's good to know.

That's a decent steer. No wobble, was most likely a railrunner. A straight runner will be all over the track. He probably had lighter wheels.

 

[bracketracer]

As was stated, he may have had lighter wheels. I would add that your car may have had a more efficient alignment that caused you to lose less speed per foot on the flat. That might be why you reeled him in. Otherwise, I think the lighter wheels would have got him off the line in front and kept him there.

 

[W&K Creations]

what about the weight position....in peoples experience, does a car that is weighted more forward actually reach the bottom of the hill faster but because the weight doesn't stay on the hill as long does not have as much speed after the transition and the car with the weight farther back which comes off the hill with more energy now can overtake the first car given enough track length....

I only ask because ive seen a few videos of our own race here and there were some cars that I saw where it looked like there was weight on the front of the car, and certainly on the SRs, because some of these models have short wheelbases, some of them the weight is centered further down the track than other cars at the start gate, and in some of these it sure looks like they have an initial faster burst and time down the ramp but get overtaken fairly quickly once they hit the flats....

perhaps its the combination of light wheels giving him the faster start with less MOI to overcome, but if his weight is in the middle and not as far back as yours, then once past the transition your car has more energy at the bottom and eventually overtakes his despite his lighter wheels...

im sure txchemist could come up with a great scientific explanation however!!!

 

[Guest]

As was stated, he may have had lighter wheels. I would add that your car may have had a more efficient alignment that caused you to lose less speed per foot on the flat. That might be why you reeled him in. Otherwise, I think the lighter wheels would have got him off the line in front and kept him there.

+1

 

[GravityX]

I agree with the light wheels and steer. But, as WK has mentioned, it is possible the weight placement may have had a little to do with it also, in the long run, but not so much at the start. You'll also need to consider the staging of the car. Was the other car staged exactly like yours? If both cars were staged exactly the same it would come down to lighter wheels and the prep used, at the start. In the long run, it comes down to steer and weight placement. So many factors to consider as to why the other car got the jump and why you then passed it in the end. As proven here time and time again, just because you got the jump doesn't always mean you're going to be the first to the finish line.

 

[AUPatrick]

that's good information. As far as staging, they were all staged by the same guy. Who knows if he staged them correctly, but in all three of the races that we went head to head with this guy his car got off to a quicker start. I assume that since it happened on all three races that they were staged similarly.

I guess it is possible that he had lighter wheels and didn't do much prep (or correct prep) and we took him at the end. We had the axle polishing kit, the wheel bore polishing kit and Legends, so it could have been wheel and axle prep (with derbydad products and advice here) that got us the win.

I'm just glad we were (more than likely) not doing anything wrong. I will try to decrease our steer this year to 3 inches. We are building three cars this year and the night before we will get the opportunity to test the cars on the track. I'm hoping that a better steer and (red rocket) will get my sons car faster than last years.

Thanks again for all of your help.

 

[Quicktimederby]

I can't wait for the 63ft race to see how super light wheels compare to the 2.0gr. Should be very interesting.

Otherwise, I think the lighter wheels would have got him off the line in front and kept him there.

 

[DerbyDad4Hire]

It might have been light wheels.

Cub scout staging will also have an effect. If anyone remembers Cash would have won a certain bearing race if his car wasn't staged so poorly.

The 63' race will rule.

 

[txchemist]

What will that 63 footer look like, a long BestTrack, a long Wood circle ramp, or some wild up and down S curve?

 

[Falcon777]

Lighter wheels with a less than stellar bore polish/wax prep. This would give an initial acceleration advantage but after the 3G transition, drag in his bores began a deceleration and with little initeria in the wheels, he experienced a higher rate of deceleration. And, it could be your heavier wheels and superior bore prep carried more initeria like a fly wheel and helped your car sustain energy while the other car petered out.

 

[DerbyDad4Hire]

S Curve!!! Now we are talking!!

It is an extended Best Track.

 

[bracketracer]

I can't wait for the 63ft race to see how super light wheels compare to the 2.0gr. Should be very interesting.

Otherwise, I think the lighter wheels would have got him off the line in front and kept him there.

THAT is going to be a whole different animal I think! Do you go for max speed at the bottom of the hill or some sort of heavier weight wheels to try to keep it chugging along?

 

[txchemist]

my prediction --- Results of the 63 ft race

unlimited wheels 4.2188
1 gr nitro wheels 4.3183
2 gr wheels 4.3558

If all cars made by Quicktimederby

 

[GravityX]

In my way of thinking I would have to give the 2.0 gram wheels the advantage for the long haul.

I can't wait for the 63ft race to see how super light wheels compare to the 2.0gr. Should be very interesting.

Otherwise, I think the lighter wheels would have got him off the line in front and kept him there.