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Mel,
That is an interesting idea. One of my concerns is the placement of the additional magnets so the downforce is at a similar level and in the same location. The other issue is the ability to do this work at home without a Magnet Marshall. I think it might be time consuming to have everyone try to use the Magnet Marshall before a race. We would have to have a deadline by when all the magnet tuning would need to be completed by.
I would like to get input from the club before the next race so if we decide to move forward with magnet tuning to level the playing field we do so before the race so we all know how it will work moving forward .
Was the magnetic down force specific to a model that put the motor at a unique location above the track? Or was it a batch of motors that are stronger magnetically. My Elva motor is faster on the dynamometer than my Lola for no obvious reason.
Marty,
I was also thinking about the placement issue after I made that post. We’d have to approach it in such a way that we are replicating the downforce of the motors in as close a fashion as possible.Radial TA,
From what I observed, it was across a wide variety of models with no discernible correlation to a specific model. It could be a batch of motors if this was from a series where everyone bought their cars around the same time.
In general –
I’ve heard tales about how fast the Thunderslots are and how well they stick to the track. I think we might have an explanation for that now. I will also be very honest in acknowledging that my car was not tuned worth a damn and y’all are excellent drivers and tuners. I don’t want to sound like “Mr. Sour Grapes” because I got smoked, but I think it’s all worth considering.I think the downforce issue is dark hole to go down. We ran Thunderslot 4 times before last Saturday and we never had a limit on downforce
By far the biggest factor affecting downforce is tire diameter. Downforce is inversely proportional to the square of the distance between the motor and the braid on the track. If you halve the spacing the downforce would be 4 times as strong.⁸ To decrease downforce, true tires to a larger diameter. With the Thunderslots I think we are all using as small a tire diameter as we can get without the chassis or spur gear dragging. Motor pods in a series with adjustable offset ùmotor pods, the downforce would be adjustable. I think trying to adjust downforce with magnets would be a futile exercise. Buying extra motors, mounting them in a chassis to find acceptable downforce would be expensive and probably also futile. We ran the series 4 previous times with no limit on downforce and my preference would be to “forgit about it”.
Russell
After my previous post about considering a mag level and ride height, I read Russell’s post. He is absolutely correct. “Forget about it”.
Lotus Jr.
Having trouble sending pic
its of a pic in 2019 checking downforce
Attachments:
All, in the spirit of fairness, I don’t see why someone couldn’t add small magnets to slightly increase magnetic downforce. We could simply set a new maximum for Thunderslots.
Do I believe this will improve or decrease performance? We’ll only know by testing.
It’s unfortunate that we have such large variances.
I’m torn on this one. My science-guy mind says, wow! Fun experiment! But then the practical side of me says 1) many of our deslots were, arguably, caused by the strong downforce, and 2) it can be controlled by tire diameter.
We could check for minimum ride height at the beginning and end of the race with penalties assessed for violations after the race, but that increases the burden on the race manager.
Like Russel said, a bit of a hole to go down.
I am interested to see what Kim’s Ferrari measures at…
Build it strong.
Keep it simple.
Make it work.
(Leroy Grumman)I defer to the experienced experts on this. The large variances are unfortunate because it does make one wonder. I’m going to do some of my own testing and experimenting with it. If it makes a big difference, maybe somebody can loan me a stick of Beemans for pushing Deep Purple past the sound barrier.
At a cursory glance from the results in the past, it does not seem that the downforce gives a distinct advantage. In a deeper dive, could look at the car weight / downforce ratio and see what comes out of that, but I teach maths all day and don’t feel like doing it right now. I appreciate that y’all are willing to have some dialogue. I learn from these discussions. If the consensus is that it’s a rabbit hole not worth exploring, I’m going with Russel’s notion of “Forget about it.”
Has anyone drilled the front wheels and used a grub screw to tight front wheels onto the axle? Also, would that be legal?
Kim, it is unlikely anyone will notice the grub screw on the nylon wheel, so it has probably not been discussed as a legal issue. I know that to use the existing axle I didn’t drill out the wheel bigger, I ground the knurled ends smooth to maintain good fit. I don’t remember if/how I drilled a grub screw hole.
Kim,
I wouldn’t worry about putting a grub screw in the plastic front wheels. I have yet to see a wheel come off of a Thunderslot car. Both Ary and I are running the stock wheels with no issues. I would leave the front wheels and work on getting the car set up for the track. Just my opinion.
I would be interested to know if the Magnet Marshal as any real world correlation with actual magnetic downforce on our track. One is a large steel bar, flush with the scale’s surface, and the other is a small steel wire embedded in copper braid, slightly below the track surface. Is it all just snake oil anyway?
"Enjoy every sandwich"
-Warren Zevon
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