Scelzi Sez (and sez it to the point) (1 Viewer)

[The Counterfeiter]

Maybe I reading this differently, but I'm reading the 'or equivalent' as the documentation, not the material... and we've done enough 'government work' that it has come up once or twice... the documentation must show the material meets the spec.

not exceeds it without approval, all variance of the spec must be signed off on by the project engineer and the O.I.C. of the project...

in this case, that would be the NHRA and their Staff Engineer

d'kid

NHRA has a Staff Engineer? That's news to me! If this position actually exists, the guy probably has a degree in accounting -

 

[d'kid]

NHRA has a Staff Engineer? That's news to me! If this position actually exists, the guy probably has a degree in accounting -

sarcasm, one of our many services...

How can any of these calls be made without experts being a part of the rule makers... you need experts without a 'dog in the fight' and excluding people that are not building the pipes question is the opposite of what needs to happen. I'm not throwing anyone under the bus... I'm saying that if you're building, you're too close to the issue to help write or intrepid the rules... ask for variances if you feel you've got a better mouse trap... submit you design and built examples for testing... i.e. prototypes for destructive testing... and NHRA PRO must have the test jigs for the testing and an NHRA engineer to perform the tests...

The same should apply to changes in brakes, tires, every part of the cars related to safety... if good year says we need a rear tire 42" tall and a 20" inch width, so be it... but get prototypes, submit them to a disinterested 3rd party, and test before the rule change is made...

can a safe 4.3 T/F car be built, can a 4.5 flopper be built? Yes, but Glendora needs to be about safety foremost and get out of the way when it comes to engine redesigns, gearing, and non-safety related items...

Idea... Ballistic enclosures over engines and rear tires on T/F cars....

d'kid

 

[Keith Burgan]

For those who did not see this in an earlier post by me:
The FEA analysis performed by both the Ford and McKinney engineers show that under the unique induced oscillations suffered by Force's car (for whatever reason) the frame would have broken whether it was fabricated from 4130N, the higher tensile modified 4130 used by McKinney, or mild steel, all in thicknesses up to .120 wall.
No other team's cars have suffered these major failures and any other breakages experienced have been in standard 4130N tubing.

Roo

 

[ex-nsp]

At lunch today, a Nostalgia Funny Car owner/driver mentioned he had talked to Steve Plueger (who kicked butt at the HotRod Reunion with his apprentice Fuel Funny car driver, Bucky) about the Force fiasco- and told me what I- modesty, aside - suspected. Force's bodies generate more DOWNFORCE, and thus higher loads on the chassis than everyone else. And thus, breakage.

However, we're all speculating on what has become an emotional issue as well. Some, wth more information that others, but with all, IMHOP, not enough at this time.

Personally, I'll be afraid to visit Randy G's pit @ Pomona after my challenging his comments on the FC spec being OK,especially if he hears I've been doing minor repairs on the OTHER Randy's (and Sam's) TAFC s. DING!

I'll have the white flag waving!

 

[The Counterfeiter]

The FEA analysis performed by both the Ford and McKinney engineers show that under the unique induced oscillations suffered by Force's car (for whatever reason) the frame would have broken whether it was fabricated from 4130N, the higher tensile modified 4130 used by McKinney, or mild steel, all in thicknesses up to .120 wall.
No other team's cars have suffered these major failures and any other breakages experienced have been in standard 4130N tubing.

Roo - could you explain what an FEA analysis is and where we might view the results? And . . . does this mean that the chassis failed and punctured a tire instead of rumors to the opposite? Recieved a third opinion tonight that this is what occured.

 

[Keith Burgan]

Jim,
FEA is the acronym for finite element analysis and it is a program where a computer model of the component or part in question is subjected to various scenarios. In simple terms (and this is a basic overview) the tubular frame is broken down into its components with each tube junction assigned a code and the mechanical properties of the tubes connecting those points are input into the program. In the case of the analysis of the Force incident a "vibration module" was also used in addition to the standard program into which are input bending and twisting moments. The basis of these inputs are data that was gathered by putting load measuring modules on chassis in competition.
In the case of the Force episode it appears that the failure of the left rear tire induced the rotational oscillations which appeared to induce the failure of the frame rails. The additional X bracing in the top and bottom of the cars is designed to damp those oscillations and spread any loading throughout the frame.
By the way, a couple of crew chiefs that i have spoken to feel that the new bracing may have made the cars more consistent.
As for viewing the results of the FEA deal you will probably have to spend $50,000 plus on the software and then find a funny car to instrument so that you can input the correct values.

Roo

Roo

 

[unclebob]

Roo; help me out here. If I walked into the room with that chassis up on the screen, carrying my three pound shot mallet to help induce a simulated tire shake vibration, do you think the monitor would live?

Bob

 

[john348]

Roo; help me out here. If I walked into the room with that chassis up on the screen, carrying my three pound shot mallet to help induce a simulated tire shake vibration, do you think the monitor would live?

Bob

no Bob because it makes more downforce than any mallet ever made to date...

 

[The Counterfeiter]

Jim,
FEA is the acronym for finite element analysis and it is a program where a computer model of the component or part in question is subjected to various scenarios. In simple terms (and this is a basic overview) the tubular frame is broken down into its components with each tube junction assigned a code and the mechanical properties of the tubes connecting those points are input into the program. In the case of the analysis of the Force incident a "vibration module" was also used in addition to the standard program into which are input bending and twisting moments. The basis of these inputs are data that was gathered by putting load measuring modules on chassis in competition.
In the case of the Force episode it appears that the failure of the left rear tire induced the rotational oscillations which appeared to induce the failure of the frame rails. The additional X bracing in the top and bottom of the cars is designed to damp those oscillations and spread any loading throughout the frame.
By the way, a couple of crew chiefs that i have spoken to feel that the new bracing may have made the cars more consistent.
As for viewing the results of the FEA deal you will probably have to spend $50,000 plus on the software and then find a funny car to instrument so that you can input the correct values.

Roo

Thanks for that information! Couldn't the guys with the $50K software just send me a pdf? -

 

[Randy]

For those who did not see this in an earlier post by me:
The FEA analysis performed by both the Ford and McKinney engineers show that under the unique induced oscillations suffered by Force's car (for whatever reason) the frame would have broken whether it was fabricated from 4130N, the higher tensile modified 4130 used by McKinney, or mild steel, all in thicknesses up to .120 wall.
No other team's cars have suffered these major failures and any other breakages experienced have been in standard 4130N tubing.

Roo

Come on Keith.

How can they say this? Based on a "model" on the screen? A program is only as good as the programmer. That's why I said before, computer models don't make runs, funny cars do. I was told the pipes that broke on Hights car on black Monday showed up as blue (low stress) in the model. Interesting how the computer model verified these pipes with the least amount of measured stress yet they are the ones that broke.

And when Del Worsham was knocked unconscious by a catastrophic tire failure in Reading you are saying all those engineers have direct knowledge of the physics involved in Del's deal and that it could not possible have been as bad as Force's just because his 4130N Grant Downing built chassis stayed together and Force's didn't? And everyone came to this conclusion how? Keep in mind he hit the wall after being knocked out and the chassis still survived!

Sorry, all the fancy wording by the finest engineers (some of whom come to their conclusions by asking the chassis builder what they are supposed to think) are trying to make this go away and it's not going to happen.

Since Nixon Watergate I haven't seen such a rush to cover someone's a$$ as we are seeing now. Unfortunately, we all witnessed John Force just about kiss his good-by. Armed with information from those finest engineers, Force has already said he will "never" have another heat treated tube in any of his frames. What does he know that you don't?

I know what he does that you don't. He sticks his kids and himself in them. And he has made his feelings on the issue perfectly clear, seems to me.

No offense, but...sorry. Only the fires here in So Cal have more smoke than we're being fed on this.

RG

 

[Keith Burgan]

Randy,
Jim asked what FEA was and I explained it with an example of the results from an analysis. If it was just Murf's engineers that were coming to these conclusions I could possibly support your premise but the Ford guys have been heavily involved and a huge amount of input on all aspects of the design, materials and construction of the chassis has come from John Medlen. Have you talked to John about what he has researched? It could be a very long conversation as he has been very busy.
I never referrenced Del's episode, just Force's and the knowledge that I have of it and the subsequent analysis.
There is no smoke here, just facts. I don't know why JFR is the only team that is having problems but Tony Pedregon just cycled out a chassis with around 125 runs on it without breakage and I would guess that some of the other front runners are in the same situation. Did Ashley Force's car come apart when she slammed the wall at Seattle? Did Hight's car suffer massive main frame rail failure when he hit the wall at Topeka? (twice). It killed the frame forward of the motor plate but that was the car that they ran from the Indy test session on.

Roo

 

[CrewMan]

Damn...now that is saying like it is. I've always liked Scelzi, and he has never been one to mince words.