FEEDBACK ARTICLE – TUBULAR TALES – AN INVESTIGATIVE STORY

Well done and about time this subject was fully addressed.  Don't stop until you have all the answers, the life or lives you save will be worth the effort. - Mike Wood

Great job guys.  I appreciate your willingness and courage in writing such an article.  Definitely overdue considering the losses and near losses we have had in our sport. - Alan Bradshaw

There has been as much hand washing as there has been finger pointing.  What every organization involved should take into consideration is that if there is in fact another catastrophic failure resulting in death, the sport of drag racing as we know it will be litigated out of existence. To the fan base as well as the sponsors contributing their corporate funds, it makes all wonder what the hell is going on? Lest we forget, Goodyear is on the verge of a "faith collapse" with their tires. Can you imagine being a driver and wondering what will ultimately betray me - chassis or tires? How did we ever get to this point? - David L. Gutierrez

Thank you for the new article about the chassis issue going on right now. Two things I would like to point out. The chassis that Todd Paton got was originally built for John Force, not Paton.  Todd bought the chassis new from John and purchased a body from Del Worsham to run with it, but the car never saw the track.

The other one is where you mention Medlen hit the wall the day before his fatal crash. Medlen hit the wall Sunday with his white AAA body, but was running his back up Syntec body for Monday testing, so there would be no issue with the body from hitting the wall the day before, since it was a different body. - Paul Songas

Jon, thank you so very much for trying to save Wally's baby! Hopefully cooler and "smarter" heads will prevail, and NHRA will once again become what Mr. Parks had envisioned! - Raymond Rupert

I cannot believe that an NHRA person would say that we have to accept fatalities in drag racing. Why would ANYONE make such a statement? One is too many! - Ed Quay

Great investigative reporting

The problem is not just the hardened versus normalized 4130 debate - it's about a need for a complete and extensive analysis of the loads affecting T/F and F/C and a rewrite of the specs - research indicates a lack of proper strength and safety from front to back not just cage and back half, plus weaknesses in Funny Car body mounting.

If NASCAR was faced with a dilemma like this I'll bet Mike Helton would call ALL the owners and fabricators into the "Trailer" and tell them . . ."Fix this stuff, boys!"

Mr. Compton, Mr. Light? - Norm Porter

Very good article. This is the only way to force NHRA to further evaluate the problem and come up with the right solution. I've seen Chuck Haase's device in person and it is impressive. This is something he does with his own time and money with only self satisfaction as a reward. - Greg Schenck

After reviewing the fix by McKinney and Co. I believe the heat treated chassis with the fix installed will break again at the same place if the tire problem reoccurs. I do not think the fix addresses the problem of a compressive flex of the top rail at the roll cage juncture. - Dave Benjamin

I'm a roundy round guy with a love for the T/F side of drag racing. I also think that John Force is a tremendous asset for all of motor sports and it saddens me to see the tragedy and injuries John, his team and family have had to endure this season.

As a builder of NASCAR Modifieds as run in New England several years back, I was very particular about the tubing I used, and have been very alarmed about the use of heat treated "pipe," even though I can understand the acute desire for repeatability and consistency, especially since they are trying to control so much weight transfer.

That said, considering the variances in heat treating results, I think you could get better and more consistent results using Condition N tubing, as long as you are willing to buy a production run of a mile of tubing. While that sounds like a lot of pipe, in reality, according to my hand held, that would involve no more than 35 Dragster chassis or about 50 chassis built for Funny Cars. While even Murf McKinney might not build that many chassis in a season, there is no reason why several builders couldn't share a production run and divide the tubing between themselves.

It seems to me that even if there is just a modicum of doubt about the reliability and safety of heat treated tubing ALL builders would be willing to err on the side of driver safety and abandon heat treated tubing. I just don't understand how McKinney and his bunch can justify the hard line resistance.

I commend Jon Asher for his excellent, well researched and documented work. I admire his courage as well, because he has obviously taken a counter-establishment position, because it appears McKinney has stacked the deck on the safety committee.

It is heartening to note that Gary Scelzi and Alan Johnson have weighed in on the side of Condition N tubing. I only hope that JFR will opt for the Steve Plueger chassis for Robert Hight in the last two events, and not run Ashley or any other driver if Plueger chassis can't be secured for them as well. - Miles Nelson

Great article!  I have been asked by several people on my thoughts about the recent John Force racing incident.  I feel using the term accident is not really correct.  This is the first where I have seen some real analysis of the situation with some facts, not just opinion without sufficient investigation.

Now for some of my opinion, based on what your article presented.  As a metallurgist (CA State registered P.E. in Metallurgy) I agree with your general conclusion that heat treated tubing is certainly a contributing factor in the chassis's tearing apart problems, if not potentially a main factor.  I think there are many variables that are present here and to assign a singular root cause will take additional failure analysis, lab investigation and testing.

One thing that I might add is that heat treated tubing will lose any heat treating strength benefit in the HAZ (Heat Affected Zone) of the weld.  Any welding stress analysis will always assume that the weld and the HAZ are lowest possible properties (similar to normalized).  Besides having the lower elongation in the heat treated tubing versus normalized, you also create a metallurgical notch.  A metallurgical notch is best described as having a difference in properties, causing an increase in the localized stress at the transition area.  I feel this is a factor in the tubing tearing apart.  Not just because heat treated tubing has lower elongation.  The lower elongation makes this metallurgical notch problem worse.

The problem of significant stresses on the tubing due to a catastrophic event (tire failure, hitting a wall, engine shrapnel damage, etc) can increase the loads far beyond design limits when using static or fatigue based analysis.  While heat treated tubing may offer fatigue life benefits, I feel these are lost due to the heat of welding destroying the strength in the weld and HAZ.  Dynamic analysis is very difficult to model or even test in real world conditions.  Since each catastrophic event can be a unique set of conditions.

Unfortunately in most of racing, the safety rules are developed after the fact from bad accidents.  The post accident analysis develops theories and potential corrective actions which are then evaluated.  Those that are effective are implemented for prevention or limitation of the failure from that cause.  I can only hope that there will be substantial failure analysis and real root cause is determined.  Not just treating symptoms.  Only when a true root cause is identified can an effective corrective action plan be put into place to prevent recurrence.

I have to question why the heat treated tubing is considered acceptable for a dragster chassis, but is (depending on your specification interpretation) is not allowed for Funny Car?  I see these as essentially similar applications and would not recommend heat treated tubing for either of these applications.  In fact I would not recommend any heat treated tubing for a race car chassis, regardless of class the car is run in.  For nearly all steels, there is an inverse relationship between strength and ductility (which is measured in a tensile test by elongation).  In general, a higher strength version of the same material will have lower ductility.

For catastrophic events, the ductility of metals can be a much more significant factor than the tensile strength.  As the ability of the metal to deform and plastically deform without failure is more important than the higher yield strength.  Heat treating has a definite place in the application of metals, but as in all good design practice, there is a right and wrong way to use the advantages of heat treating.  In the case of chassis tubing, it seems that heat treating is not one of those applications where heat treating provides a benefit.  In fact it would seem to be a negative application where it has detrimental results. - Terry Pehrson

THANK YOU for your article.  Not only from a spectator who has a mechanical interest in the cause of the accidents, but also as a Mechanical Designer, who has long complained to anyone who would listen about the long rash of chassis failures in the fuel classes.

The black politics of NHRA (the IMAGE of safety) just plain disgusts me.  I have written to them many times on many issues, and never received replies.

Thank you again for taking this stand.  There are many of us lowly spectators on your side.  Please keep us informed. - Chris Saulnier

This is an excellent article that is dead on correct. I was approached two years ago by a T/F crew chief about the affects of welding HT4130.  I said why are you using HT4130 in the first place? He hooked me up with various experts involved with NHRA so I could get a better understanding of how this evolved. After a few weeks of investigation the picture started to take shape.  I grew up in this sport and I love it dearly. As kid I use to help Gordon Collet when he built his own T/G cars. From what I know so far it's beyond me how certain people can sleep at night. This is common sense stuff.  Make the right decision. - Stephen J. Studer