Quest for the Golden One: Mod Rod

TheMakersBox Saturday, 8/14/2021

I’ve been following the Case Race videos over at Xtreme Diecast Racing looking for candidates to try out. Recently, an unexpected contender, the Case K Mod Rod, made it to the semi-finals. While it didn’t survive the round, I was intrigued because it seemed like a light casting to do so well. I was hoping that meant the wheels would be good candidates for racing, especially since I love the Deep Dish 8-Spoke wheels.

So, the questions are:

  • Was that an exceptionally fast Mod Rod?  
  • How would you know if any given example of a casting is exceptional?
  • How many examples of a casting would you need to buy to expect to find “The Golden One”?

When I find a casting I like, or intend to race, I typically buy ten or more of them and test them on my 16 foot track with a timer.  I then take the fastest of them to build, and the rest go to the grandkids.  I wanted to do something a little more rigorous with the Mod Rod, so it was time to gather some data and dredge up some Statistics. 

As I expected, the Mod Rod is fairly light, at about 28 grams.  A speed under 1.7 seconds on my track is about the cut off for getting my attention.  As you can see, two cars, #1 & #11 met that criteria and would be good wheel candidates.  But are they “The Golden Ones”?

Data sets that are the result of a combination of random effects typically follow what is known as a “Normal Distribution”, meaning that most values will fall around the average, or mean, while tapering off towards the edges.

By M. W. Toews - Own work, based (in concept) on figure by Jeremy Kemp, on 2005-02-09, CC BY 2.5, commons.wikimedia.org/w/index.php?curid=1903871

With a mean (average) of 1.724 seconds, and a calculated standard deviation of 0.027, we can create the normal distribution and show where the examples fell on the curve.

This shows us that the two fastest examples we found are just below one standard deviation below mean, and that to get to 1.67 seconds, or two standard deviations, we would explect to test at least 50 cars!

In summary, yes Hot Wheel performance follows a normal distribution, but to find an exceptionally fast car, you would have to test a lot of examples.  For now, I think I’ll stick to my 10 car strategy, but at least I have a way now to calculate if it is The Golden One.

And, if you are interested, here are where Mod Rod #1 wheels went!  They are going to Monster Motor Sports Scrapper Showdown!

Next in the Quest for the Golded One we look at the 2019 Kia Stinger GT.



Discussion

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BiscuitBrown 8/15/21

Woah! 

1.  I wish you were my grandpa!  All mine ever gave me was a kick in the pants.
2.  Thanks for breaking this down.   I learned a lot and will use this going forward to help find good castings/wheels.  Really appreciate the breakdown and explanation!  


  • Without including the grandkids, I would have no way to justify this hobby to my wife! — TheMakersBox
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redlinederby 8/15/21
Site manager

It's like being back in school! Good stuff, though, with the moral of the tale being - to find a fast out-of-the-box one, you have to test a lot. 

Although what I find interesting about your journey here is that you tested all the Mod Rods to find a fast one, but then took those wheels off and put them on another body...? Doesn't that negate any testing you did with the Mod Rod? I mean, getting fast wheels is ideal but if the receiving body/chassis is crap, then the wheel data doesn't matter...or does it?


  • My assumption, which needs further testing as well, is that the wheel/axle combination are the biggest factor in speed. To your point, however, the car I built was actually slower than the original, even with weight and graphite! There is still so much mystery in getting a fast car built! — TheMakersBox
  • I think you're right though :) Wheels/axles make the biggest impact next to weight distribution. I think the plastic body cars with metal chassis is the winning combo. But plastic bodies are somewhat hard to come by. — redlinederby

Great article! And that pink Chevy is killer. Looking forward to seeing more science!

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VoxxerRacing 8/19/21

Comes down 3 basic " rules " :    1 - long base.  2 Correct Stance - wheels are rectangular stance - equal width, front and back.  3 Best wheels size and type.   

But what do I know ..........    Voxxer 


  • You know a lot, Jon! That I can attest. Your rides are fast! — Kaiju_Colorado
  • Indeed. Dare I say it's not rocket science, it's high school physics. But even then it's far from what I'd call "easy" — redlinederby
  • There is definitely an artistry to being a good tuner. Just because someone has the right parts doesn't mean their build will automatically be fast. Being anal and patient is a big part of it too. Voxxer's rides are fast because he doesn't accept anything less than perfection. Just the amount of wheels he farms just to find a perfect set is crazy. But you cannot deny that his work, time, and money pays off. — Kaiju_Colorado
  • Kaiju_Colorado Thx for the kind words .... now back to building racers !!! — VoxxerRacing
  • Voxxer, you know a fair bit more than the rest of us! Tell me more about wheel size and type! Point me to my next candidate to test. — TheMakersBox
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