Derby Talk

I've been a proponent of NyOil in past posts but I am having some second thoughts now. I think NyOil is better than graphite IF it is applied correctly, but worse if not. Something I've also noticed recently is NyOil's tendency to pick up debris. Keep the axles clean and apply a VERY thin coat (I wo...

I've tried flex designs and they haven't worked well for me. Any minor advantage gained by cushioning the weight is overwhelmed by alignment problems. If Grandpa were winning against hundreds of other cars (as others on this site are) that would be different, but I think his competition is limited s...

Yes, if you can see it you've got too much.

One other observation on NyOil, be sure to apply it in a "clean" environment. Any dirt or debris flying around will stick to the oil and you don't want that stuff in your wheel bore.

DG

Exactly my point, with a long runout you can't be as aggressive with COM, i.e. you can't place it as far back, taking weight off the front wheel, because you need that weight up front for stability. Now, my experience has been that the stability problems pop up much more at the end of the run, yet t...

Joe,

You make a good point about front wheel stability, and downforce defintely helps there. That's why stability problems manifest at the end of the run, as the car slows and the downforce decreases. So the longer the track, the less aggressive one should be with COM placement.

DG

Joe, I see what you're getting at, but the air isn't attached to your car. We're really splitting hairs here (what's the mass of the air displaced by a PWD car?) . When your car is sitting at the starting gate, the potential energy it has at that point is all it's going to get (putting aside mercury...

The propelling force on a PWD car is gravity, gravity acts on mass. If you aren't increasing mass (or drop) you aren't increasing your propelling force. Everything else is designed to reduce resisting forces.

My daughter and I had a similar "cheater bar" experience. Also, last year we built a "modified flex" car where we used a scroll saw to create an independent suspension for each wheel (three touching, of course). Did extensive alignment testing a couple days before racing and had ...

Findings: Just compared the two cars on a "Stan kitchen table alignment machine" (modified to 4" rise), and found the new car ran the ~6' table a full car length ahead! 80% of the difference is realized in the first foot of travel as the new car pulls away MUCH faster. I've noticed th...

I built a flex car this year, or at least a semi-flex car, and was somewhat disappointed with the performance. I also built a non-flex car and it was faster. Unless the track is exceptionally rough I don't think there's much benefit to a flex car that can't be captured by simply isolating the weight...

Sorry to be dense, but which two do you mean? (graphite, NyOil and silicone being the choices)

The "cost" of gaining the inches is just the effort to put the weights further back Not what I meant. My point is you gain 2"-3" with the more aggressive placement, but you will have to "pay back" some or more than that due to less front end stability. The pay back cost...

Terry,

I'll be interested to see what your conclusions are for Silicone vs. NyOil!

I've experimented with NyOil and it seems to work pretty well. The key is to go light with it. The instructions say use two drops, I would only use one, then wipe off the excess. On my first try with NyOil I used way too much. The way I've applied it is to put one drop on the axle, then twist the ax...

Wow, I haven’t seen an inch generate this much discussion since USC’s phantom touchdown against Cal in 2002! Sparky, you have some very useful information at the link you provided. Your results (Test 2) show a 1% improvement (about 4.5 inches) in finish for a CG at 1.5” from the rear versus 3.5” fro...