422 replies to this topic

[Bench Racer]

This is the COTA Smack thread, correct. It is my belief there are some people blowing smoke in the last few posts. Why in the word would anyone believe any parts supplier (short of a backyard garage rebuild) who rebuilds rear axles tend to believe said rebuilder would regrind bearing cages? Tom, your comment "imperfections are machined out by hand, new (larger) balls are fitted and the cages are clearanced  by hand and reassembled", maybe in Ralph, Michael or ???'s shop, do you believe the stuff you post, really. And Tom if you truly believe I missed this, your words, " You left off remanufactured, rebuilt, and refurbished from your terminology list." You my internet friend need quit typing posts and read a bit about the Cardone company. 

 

If y'all want to see rules to defeat cheating go read the rules for Spec Race Ford. These rules are called consequences for your cheating actions. Do I believe there is no cheating in Spec Racer Ford, yes, but there cheater rules have I'm sure got car owners/drivers attention.

[38bfast]

Gee, some tough questions to be answered here.
 
All assuming that the axles in question actually were a commercial re-man part, of course - in my opinion, if it was an intentional modification to improve performance, it should be a DQ regardless of whether it 'worked' or not. There's a principle to be defended, lol.
 
And (just to play devil's advocate) if re-manufactured  parts with significant machine work/oversize components are now going to be legal, shouldn't everyone immediately order a 0.40 over rebuilt engine? Same deal, just someone making a worn-out part useable again.

Over bore of the engine is leagal now. And owners are allowed to “remanufacture” their engines.

[mdavis]

I agree with Novak, if this is all that they could find after stripping these cars to the bone, then as a spec class, i would say that we are in pretty good shape. As for the DQ on these half shaft cages, I an not in the loop, but if these DQ's are going to stand then my already suspect opinion, of NASA has not improved. That is a Weenie DQ in light of all that we have discussed in this thread about lack of standards and no objective proof of a rule violation. 

 

The right thing to do IMO is to issue a warning to all, and to legislate a rule if you think that there is a problem with this part. Rules need to be address in the rule book not the tech shed.

 

As someone said above, the rules need to be addressed. If these parts have not been made in 10 years, then the OEM spec is worthless, you can only enforce that spec if you can provide the part.

 

So we should be talking about a rule clarification allowing remans Period.

Not a sexy post but here's my two cents:

 

I looked at the Mazda parts catalog and could not find these cages.  I assume they are no longer available from Mazda. So either we can allow this type of rework with tolerances since we cannot get the part or just say they cannot be touched and everyone has to get 200,00 mile units from the junkyard if they can find them.  

 

The fact is that these cars are 25 years old.  As we've all acknowledged this is a much bigger issue than a cage rework.  We need to address the parts availability issue.  -- See Formula Vee.

[powerss]

Has anyone gone out and bought "new" half shafts from anywhere yet and opened them up to see what they look like? I would like to see that before speculating what a reman joint looks like.

Is there a reason the inboard joints arent being questioned?

[Steve Scheifler]

In no particular order:

Inboard are different and all would fail the ball/cage go/no-go test.

Get “original” ones from a salvage yard? What makes you think they weren’t already replaced once?

Cages and other internals were never available, the CV is considered non-serviceable.

All known generally available retail remans pass scrutiny, there is no need to make a BFD about them. That smacks of smoke and fear mongering.

I still don’t see a DQ here, but my old shop teacher had a really wicked paddle...

[Steve Scheifler]

I am SO bored that I popped the $28 required to download an SAE paper with the calculations and tests of CV joint efficiency. (930906 if anyone is interested)

I’m not allowed to share it in detail but the type of CV joint in question (Rzeppa) is significantly less efficient than the Tripot version often found inboard (though not on NB Miatas) but it is still quite efficient at low angles of articulation. That angle depends on ride height, camber and toe but until I can make it to the shop I’ll use an angle of 5 degrees. If you run more ride height or more camber it will be less. (Toe is negligible).

At 5 degrees the joint is approximately 99.5% efficient. So TOTAL LOSS by friction per outer joint is roughly 0.65hp. So that’s the holy grail physics defying make you a buzllionaire maximum possible “gain” per CV.

The whole point of the SAE paper is the potential MPG benefits of an improved design and better lubricants. Their working target is a loss reduction of 20%, and THAT’s worth a technical paper, and a lot of money for someone who can do it. Applied to our scenario their best case GOAL is to “gain” 0.13 hp per CV. And that’s probably not happening in 5 minutes with a die grinder!

Clearly, the amount of performance advantage, if any, is not considered relevant to whether or not rules were broken But wherever this lands they still need to do something with rules and/or specs going forward. My point is that they should know what it’s worth before they decide. I’m saying it’s worth less than 0.05 hp per axle and you may give that back if the contact pads (it will still use them to some degree) aren’t polished. In fact, if you aren’t using the lubricant I’m using, you are losing more than this.

[Johnny D]

Anybody else receive this today?

Thank you for joining us at the 2018 NASA Championships and Toyo Tires Classic race.

As you know, the results have been held as provisional because of the post-race inspection process. The NASA technical team worked very hard to ensure compliance with the rules and found certain parts on competitors’ cars to be non-compliant. The technical team spent additional time after the event to consult with independent experts and submit the parts for evaluation.

NASA has confirmed their findings in the linked white paper below and has notified competitors who are subject to penalties. Competitors have the right to an Executive Appeal and some of the drivers, in this case, have requested that hearing. With that in mind, we ask that you remain patient so work can be done to give everyone the rights and fairness afforded to them. We will release the official results as soon as this final hearing is concluded.

We appreciate your support and hope you had a good experience at Circuit of The Americas. As you have seen in the past, controversy in racing often creates a political backlash or efforts to damage the reputation of one side or another. It is our hope that everyone can look at this as NASA's desire to do the best possible job to enforce the rules and nothing else. As a competitor, you expect a sanctioning body to ensure fairness and remain objective. We want each and every one of you to know that principle is paramount in this entire process.

Sincerely-

National Auto Sport Association

 

Has anyone heard when this final hearing is ??

 

J~

[Tom Hampton]

I'm liking my back of the envelope 0.1 hp swag. I didn't even pay the $28 or read the paper.

[Steve Scheifler]

I'm liking my back of the envelope 0.1 hp swag. I didn't even pay the $28 or read the paper.

And I’m liking my WAG that you were still high. Doesn’t the closest without going over win?

Correction: if your WAG was both combined, and if 5 degrees articulation is correct, then you were spot on!

[powerss]

SMMD says the results are in.......If it is true then the DQ held up.

[Johnny D]

Official Results

 

http://timingscoring...es Classic).pdf

 

J~

[powerss]

In no particular order:

Inboard are different and all would fail the ball/cage go/no-go test.

Get “original” ones from a salvage yard? What makes you think they weren’t already replaced once?

Cages and other internals were never available, the CV is considered non-serviceable.

All known generally available retail remans pass scrutiny, there is no need to make a BFD about them. That smacks of smoke and fear mongering.

I still don’t see a DQ here, but my old shop teacher had a really wicked paddle...

 

Steve

 

By "new" I meant remanufactured and available from ANY source including Mazda but even any of the standard parts stores.  

 

I would not expect much benefit of the inboard joint.  The outboard joint carries more articulation angle.

 

If most of the reman sourced part look nothing like the modifications that were made on the suspect parts then I think that is the point of the concern.

 

I think the top prep shops leave nothing to chance.  That is why they are the top.  I think the benefit is tough to quantify in normal testing methods.  Corner loading and suspension travel (kinematics) will PROBABLY accentuate the benefit. I just don't know and I have no intention to speculate.

 

By the way Fuel Economy is tested on a chassis dyno so FWD steering angles don't come into the equation for improving FE.  Therefore, if SAE is looking into it, it may be closer to our situation than you are suspecting.

[Tom Hampton]

Yes. WAG was total gain for both sides combined.

[Steve Scheifler]

Steve

By "new" I meant remanufactured and available from ANY source including Mazda but even any of the standard parts stores.

I would not expect much benefit of the inboard joint. The outboard joint carries more articulation angle.

If most of the reman sourced part look nothing like the modifications that were made on the suspect parts then I think that is the point of the concern.

I think the top prep shops leave nothing to chance. That is why they are the top. I think the benefit is tough to quantify in normal testing methods. Corner loading and suspension travel (kinematics) will PROBABLY accentuate the benefit. I just don't know and I have no intention to speculate.

By the way Fuel Economy is tested on a chassis dyno so FWD steering angles don't come into the equation for improving FE. Therefore, if SAE is looking into it, it may be closer to our situation than you are suspecting.

Outer gets more articulation at stock ride heights and in FWD, not so for us. The outer should have less since we’re typically running 3+ degrees negative camber.

I think the FE numbers are based mostly on calculations.

Cornering loads cut both ways, one side is more loaded while the other is less. Suspension travel is a factor due to angle but for us it is low and also cuts both ways.

And of course, unlike FE tests, through much of cornering the difference in efficiency isn’t relevant to us anyway.

[powerss]

Outer gets more articulation at stock ride heights and in FWD, not so for us. The outer should have less since we’re typically running 3+ degrees negative camber.

I think the FE numbers are based mostly on calculations.

Cornering loads cut both ways, one side is more loaded while the other is less. Suspension travel is a factor due to angle but for us it is low and also cuts both ways.

And of course, unlike FE tests, through much of cornering the difference in efficiency isn’t relevant to us.

Steve

Let make this an interesting engineering study and design the test to prove the difference for SM specifically.  You can PM to discuss.  I truly would like to know if this was all in vain. Sorry I am paid to be cynical.

 

I am still holding out hope that John Mueller will elaborate on this known cheat though.

[Steve Scheifler]

We can discuss, I’ve got some time on my hands and plenty of curiosity. I considered ways to test it but knew my time was limited before interest was lost. And I know from the simplest observations and logic that it can’t be much because total loss can’t be much.

And don’t overestimate how much justification and evidence people need. Anyone can feel the difference betwwen an old loose joint and a new one, and the “fix” is even better. So it must be worth something (unless sloppy under load and RPM actually creates more friction). That’s ALL some need, and the rest will follow. Add to that the FWD guys who really do net some minor gains (at least while the wheels are turned) so there is a market already, and someone like Ed Gilfus pitching it, surely HE knows something (how to make money at least), and here we are.

[Steve Scheifler]

Correction: In my post explaining the calculated friction loss and potential benefit I showed a potential gain of 0.16 hp. That was for a greater angle. At 5 degrees and a loss of 0.65 the 20% goal would be 0.13 hp. But I’ll stick with my very generous 0.05 estimate of actual.

[Steve Scheifler]

Doh!! I just realized, for the total loss estimate I used 130 HP, which is reasonable but of course that’s the total to both wheels combined! So the estimated benefit isn’t 0.05 hp per axle, it’s 0.05 hp total. Maybe I’ll save my $$.

Sorry Tom, but you can keep the prize money.

[Johnny D]

Measure twice, cut once.

 

Just sayin,

 

J~

[Steve Scheifler]

Measure twice, cut once.

Just sayin,

J~

They don’t allow me to use sharp implements.