Cars Slowing Down Every Run

[davem]

Our Awana Grand Prix Race was last night.
Looking at the data for the top cars, it appears that cars were slowing down after every run.



It is a new Piantadosi 48 ft. Aluminum track.
Same chart on the day we set it up for testing does not show such a pattern of increasing times.

I thought the timer may be "slowing down" as the race progressed, but the leaders race was run at the end (4 cars, 4 heats) and showed the same pattern of first run being the fastest and then slowing down from there.

Could something from the track or stop section be "polluting" the wheels / axles and gradually slowing the cars down?

[3 Cub Dad]

There are a couple of possibilities. My first thought would be graphite breakdown, expecially on that long of a track. But to be that uniform, I would expect contamination from the track. After every car has run down the track one time, there is usually a LOT of graphite on the track. (From the last minute lubers who think that more is better!) We normally try to brush down the track after everyone has run once, and you wouldn't believe how much we get off the track!

[doct1010]

Hmmmm. Tough one. Check the wheels for nicks.

[davem]

No nicks or car damage.

The track was very well aligned.

The graphite pollution might well be the cause.
There were several "heavy graphiters" puffing graphite in prior to the race.

Any thoughts on the stop section? The rubber coating shedding small particles?

I haven't taken the wheels off the cars to inspect yet...but suspect I will have to before regionals.

[doct1010]

If you suspect bore contamination your Krytox lubed cars would show the most ill effect. How did they perform? Was their drop off significantly greater than graphite performance?

[davem]

The Krytox cars seemed much more suceptible.

Here's the chart with a legend for lube type.

[terryep]

I would expect the lighter lubes to slow first. Silicone is fast but wears out in a long race, SB-10 (Krytox 104?) lasts longer than silicone but Krytox 100 may not.

Properly conditioned graphite lasts the longest.

I always explain this to the parents and cubs and let them chose between silicone and SB-10. Graphite takes too much work to get right.
Terry

[Stan Pope]

Properly conditioned graphite lasts the longest.

Terry, you shouldn't drop one of those and then just run off!

Tell more, please.

[doct1010]

I would expect the lighter lubes to slow first. Silicone is fast but wears out in a long race, SB-10 (Krytox 104?) lasts longer than silicone but Krytox 100 may not.

Properly conditioned graphite lasts the longest.

I always explain this to the parents and cubs and let them chose between silicone and SB-10. Graphite takes too much work to get right.
Terry

SB-10 = Krytox 103, Krytox 100 lasts far longer than silicone and most ordinary graphite we have tried. In fact longest lasting lube we have tested.

[terryep]

I guess I stuck me neck out on this one. I least I didn't get an argument on the silicone!

I have not had the opportunity to try Krytox 100. Being a lighter oil I'd just expect it to run away... I stand corrected.

Stan, as for graphite lasting well, I wasn't saying it was particularity fast, just that it lasts a long time when you have built up a "graphite bearing".

Perhaps I too am writing way too late at night! Nice too see people still
pushing the technology.

Our pack races are coming up this Thursday.
Terry

[doct1010]

Terry,
My apology if my reply appeared argumentative. Certainly not intended.
YOU are responsible for bringing Krytox to the attention of the board, IIRC, sometime in late '03 or early'04. At the time we were trying to get NyeOil to perform, to no avail. I was still in lurk mode back then. I recall you mentioning SB-10 and Krytox a Dupont product. I did some research and decided on Krytox 100 as probably the best for PWD application. In fact I believe my first post was on Krytox application and directed to you and Buckeye. In my mind nothing but KUDOS for you!!! Best lube we have found thus far.

[terryep]

Thanks doct1010, I tend to be a bit of a blow hard sometimes and it really is not my nature. I'm still using my original $20 bottle of SB-10. When it runs out I'll have to try Krytox 100!
Terry

[Stan Pope]

Perhaps I too am writing way too late at night! Nice too see people still
pushing the technology.

Our pack races are coming up this Thursday.
Terry

Good luck to all on Thursday!

And, thanks for the clarification. I was afraid you were thinkg of some obscure process, like "Prepare a suspension of 3 parts graphite, 1 part molybdenum and 5 parts tincture of xxxxxxx. Apply ..." Well, you see what I'm implying.

Don't stay away so long next time.