422 replies to this topic

[Johnny D]

here's the races
 
https://nasaspeed.ne...event-coverage/

SM
https://www.youtube....2&v=0t6lMzhNBFU

J~

[Steve Scheifler]

Wow. Each time I’ve thought about the axels as a potential cheat point I quickly moved on. I figure that to be worth the effort they would need to be the source of significant friction resulting in mechanical power loss. Power lost to friction inherently means heat, and I’ve never seen evidence of the CV joints producing much heat, so thete seems little potential gain from slightly less friction. And we don’t use much suspension travel so I would think even less.

Someone educate me here. I know that in this class we split hairs and chase every fractional HP but is there really much to be gained by modifying the axels? Apparently someone thought so unless they can point to a rebuild shop which does this routinely, and I assume that would have already been communicated. Is this a common modification in some classes or mimicking a more efficient design on other cars?

Kudos to tech, however they got onto it, but I’d really hoped everyone would come out unscathed. Still, if that was the only thing then it was a pretty clean race up front.

[Steve Scheifler]

Trying to prepare myself for the deepest of ironies...

[zoomzoom22]

The article refers several times to a spec and a remanufactured spec. I’m having trouble locating any specs, can someone point me to where they are? Our family SM I have zero clue where the axles came from so no clue what their status is.

[Steve Scheifler]

You won’t find a spec, any more than you will find one for dimensions of a ball joint, control arm, etc. In most cases the “spec” is derived from examination of a so-called OEM part and in this case also one or more aftermarket parts and from discussions with “experts”.

What this will likely boil down to is whether during repairing/remanufacturing it is reasonable to grind or machine some finite amount of material from the bearing/joint cage, and if so how much. Then there is the question of wherher it matters that I performed the reman myself vs having someone else do it, and whether that someone else is a commercial rebuilder following some imaginary standards and supplying typical retail outlets. Point being that once you allow remanufactured or aftermarket parts (and we have no choice in that for some) then “specs” get more than a little fuzzy. As a little side note, the axles have two ends of course, but I believe they are different even with respect to the ball & cage opening being cited in the white paper.

So I’m guessing they are screwed, but if it were me I would argue that given that we lower our cars to the point that the joints are always significantly angled, and that during reman efforts I’ve seen and cleaned up wear found on the cages, the additional clearance was provided to avoid such wear and possible failure. “Typical” aftermarket reman wouldn’t bother with the extra expense unle necessary to salvage an otherwise rebuildable part, but they are probably out there.

[tLinder]

https://nasaspeed.ne...championships/#

If there are DQs, in theory that would imply the cars that move up are 100% legal?

[Steve Scheifler]

If there are DQs, in theory that would imply the cars that move up are 100% legal?

As much tech as they did, it’s never 100%. For example, did they actually CC at least one chamber on each, or simply rely on the Whistler? We’ve been there before but apparently not really learned the lesson. And of course there is the question of whether the same amount of tech was done deep enough into the field. Remember Laguna Runoffs.

[powerss]

If there are DQs, in theory that would imply the cars that m0ove up are 100% legal?[/size]

That is not what happened in 2014 at Laguna Seca. They moved everyone up but it was not proven that everyone that moved up was legal. Just not logistically possible to confirm that.

[-P-]

That is not what happened in 2014 at Laguna Seca. They moved everyone up but it was not proven that everyone that moved up was legal. Just not logistically possible to confirm that.

I think that is the point Toby is trying to make...

[Steve Scheifler]

I have no dog in this hunt so I’ve just been waiting for results, but now you guys have me thinking what my appeal would be.

In addition to the foggy (non-existent) specs for reman and even aftermarket parts, which would be the core of the argument, I would also look for parallels.

One that comes to mind is the infamous front hub, or more specifically the bearings, races and cages there in. There have been countless versions with different numbers and sizes of balls, different race dimensions and totally different cage designs. All are “legal” and none are documented. People also remove the balls and replace them with higher precision parts. Mazda sells “blue-printed” ones. If it were economical to replace the races (particularly the outer one) with a harder and smoother one we would. All of that is because we’re tired of replacing failed hubs, but failures are from friction and less friction is technically a performance advantage. Love those “free spinning” hubs even though I’d rate the benefit as negligible.

Anyway, I certainly would not hesitate to come up with my own precision balls, races and cages and do the reman myself so long as it all fit into an existing hub. Given the variety of hubs out there that nobody would call non-compliant, why would mine be? They may not match any you’ll find at Auto Zone, but so what?

So now I’m looking again at the pictures of the axels and all I see is a slightly opened up cage. No precision replacement parts like we do with hubs, no REM, or coatings, or redesign, just a little more clearance for it to work as designed under more demanding conditions than intended.

I know this is the era of manufactured outrage, but I just can’t get worked up over taking a few thousandths of an inch off a bearing cage to provide more clearance and smoother movement. This isn’t another head gate IMO.

[powerss]

Why is it so quiet here? It's just weird.

I would expect much more dialogue. Especially from the people involved in this explaining their position.

[Steve Scheifler]

I should think they are waiting for appeals to be processed. Best not to stir the pot until things are final. NASA probably should have been less specific in their explanation of the delays, but I do like transparency eventually so everyone can learn and add their input if they choose.

[Bench Racer]

Will someone please state the NASA rule which allows any part other than a Mazda replacement part to be used on the rear axle/half shaft. 

[Steve Scheifler]

Bench, you always ask a variation of the same dann question. With a few exceptions, most notably engine internals, aftermarket parts are allowed so long as they are direct replacements and of same materials, dimensions etc.

[Johnny D]

Its hard to speculate who this is or effects but It will be interesting to see if the dyno numbers showed nothing or there was a smoking gun and then they just had to find it. And if the the numbers showed nothing was there an advantage?

J~

[Steve Scheifler]

There may have been suspect dyno results, I don’t know, but if so I would say there is zero chance that the CV joint issue is a measurable contributor. Zero. But that doesn’t negate the possibility that as you say the dyno triggered more searching. More likely IMO someone advised tech well in advance to look at them, whether out of purist intent or as payback doesn’t really matter. If the dyno numbers were suspect I would hope that compression ratio would have been high on the list but I an under the impression that chambers were not CC’d, relying I suppose on the Whistler. Been there before, should know better.

Back to the dyno, there were posts elsewhere stating that big vaiances were observed but that they have identified a likely but non-techable issue with the engine. Not sure how it can be identified but not tech’d, but long term THAT will likely be the important story out of all this.

[Johnny D]

I haven't been in the cage but it appears if it's stock and the ball doesn't go through the cage you have two contact points on the cage and one I assume on the inner race.
If the ball goes through then you have 2 contacts points with the inner race and housing with light pressure contact of the cage.
Why do it if there's no advantage.

J~

[Steve Scheifler]

I never said there was no advantage, just that it wouldn’t amount to suspicious gains in wheel HP. But as for why, there will always be people who do everything they can dream up that might help no matter how infinitesimal because it all adds up. But think about mechanical losses. Power lost to friction is inherently dissipated as heat. Even without trying to control other variables to measure the difference on a dyno you could use the dyno to “work” the joints under load and even run them at angles simulating suspension travel, and monitor their temperature. Somebody else can do the math if they don’t have anything better to do this beautiful afternoon, but the energy of 1hp dissipated through that joint should be easy to detect. And of course any modifications can at best save only a portion of whatever you calculate is lost. So no, I don’t think it alone is enough to make one car stand out relative to others on the dyno.

None of which tends to come into play enforcing the rules but that doesn’t mean it isn’t worth contemplating.

[Johnny D]

Just wanted to point out... 2 cages per car, right? they're 3 cages shown. 2 + drivers DQ'd ?
Oh dear..
J~

[Steve Scheifler]

Three actually, but who’s counting?