Randy,

Dead on! I've got the spec right in front of me.

II. Basic Construction Practices

1. All structural material for the roll cage, rear-end mounting, and suspension mounting must be normalized SAE 4130 chrome-molybdenum steel (SAE 4130N) purchased to the requirements of military specification MIL-T-6736B and it's subsidiary document or equivalent. ...

So you and I are reading it the exact same way... Anything other than 4310N of the required Mil-Spec is illegal. And actually that is the case in any type of SFI spec'd chassis, other than the Top Fuel cars.

Does anyone know of an addendum to the 10.1E spec that allows the use of heat-treated tubing?

__________________
Greg Stanley
2007 NorCal Top Comp Champion

From what I have read it's the "..or equivalent" piece that allows the heat treated tubing to be legal, but that could just be one persons interpretations of the spec.

Either way, I am glad to see Gary speak out and let his feelings be known, afterall, it's his life on the line every time he hits the go-pedal. Something tells me that this will not work it's way into a "Scelzi Sez" episode anytime soon.

I do not blame McKinney for building these cars. He may have info that stated it would be superior.
1) What bothers me is when Jim Head finds out after the fact that his car has heat treated rails, when he believed them to be N. That is unacceptable. A long talk should be instigated before the chassis is begun, or sold. That choice should be the teams.
2) What bothers me next is an assumption made from reading the Olsen interview, and could be less than perfectly correct. But it seems that these chassis were being created and tagged without a real understanding from the head of NHRA tech for the nitro classes. If this is the case, this is WRONG!
3) What bothers me is McKinney's lack of coming forth and stating, something like 'We were wrong. Real world testing is showing this may not be an improvement." Take some responsibility to move FORWARD. We all screw up. Accept it rather than hide it.
McKinney builds a good car. Always has. That is why so many people run the stuff. But I have been hearing about these main fraimrail problems since the first Vegas. I don't know how long the heat treating has been going on. I guess I have lots of little concerns, but these main ones really bother me.
This all happens when I am getting finalized to build my own funny-car chassis. Interesting timing.

I don't really know how to put this and I don't intend to sound harsh but... these days saying "we were wrong" is basically an admission of negligence in a court of law. Very sad. Not saying anything would ever come to that but unfortunately we live in a CYA society that goes against the grain of everything I have been taught in life.

Lets hope that there are some people involved that will make all the changes to make it safe and not worry about getting sued. NHRA needs to step it up and make the rules and enforce them to make it the best for everyone and not care about stepping on any toes.

I'm with ya brutha!

Brian,

I don't know how anyone could consider the heat-treated tubing to be equivalent to the normalized. We are talking about completely different Mil-Specs and material properties.

But I'm no metallurgist.

__________________
Greg Stanley
2007 NorCal Top Comp Champion

Greg,

I don't disagree with you, I was mentioning the fact that it seems to be the "loop hole" so to speak that was being used to allow heat treated tubing to used and still keep the chassis within SFI spec.

Remove "or equivalent" from the spec and none of us would be having this conversation. Instead we might be talking about Papa John's run at the championship, or some funny remark he made during a top end interview. We'll never know for sure if John's accident would have ended up with the same results, but if I was a betting man, I know where my money would be.

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

__________________
Comfortably Numb- Fly Navy, Build SEABEES
A friend helps you move, A Real Friend helps you Move Bodies
http://www.myspace.com/ocir_forever

You gotta admire Gary S. for speaking out so candidly on this issue.

Even though its appears that the 4130N tubing is probably a better choice than the heat treated tubing on these chassis I don't think just a decision alone to enforce the current rule on the books requiring 4130N will necessarily fix all the problems that have been occuring.

Both these tubing types are very strong. The 4130N has less strength but more ductility while the 4130HT has more strength but is more prone to crack when very heavily stressed.

If the current chassis designs are such that they are right on the edge so that the minor differences in these tubings are enough to cause a chassis to go over that edge and fail then we're putting the drivers at too much risk with the current designs no matter what kind of tubing is used, the safety margin is just way too thin.

In the short term enforcing the 4130N tubing rule is probably for the best, but the NHRA needs to figure out how to get an aggressive "car of tomorrow" design effort started as soon as possible. If this ends up with cars a couple hundred pounds heavier than the current cars that's not a bad thing, the cars need to be slowed down a little anyway.

The current rules that allow the words "8000 HP" and "0.058 wall tubing" to be used in the same sentence need to be seriously rethought.

Paul T.

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

__________________
"The Counterfeiter"

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

__________________
Comfortably Numb- Fly Navy, Build SEABEES
A friend helps you move, A Real Friend helps you Move Bodies
http://www.myspace.com/ocir_forever

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

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 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.

__________________
"The Counterfeiter"