texasprostocklover
Nitro Member
Ok, the best part of this thread were the videos - they were just awesome and hard to believe! And Paul, dude, chill before you blow a gasket! 
Toliver's runaway tire. (1 Viewer)
- Thread starter HEMI6point1
- Start date
In 1998 I believe, at Topkea, Pat Dakin had a blowover and from what I recall the engine rpm soared when the back tires came off of the ground and I believe the center of the wheel broke out. He slid down the track but the wheel bounced down the track to the racers section of bleachers and hit a lady a row or two in front of us. She was very lucky as it hit her in the face / head.
In boats with jet units they call that cavitation , its when the load (which in boats would be water but in this case is the tires having to grip on the ground) gets lifted which in this case would be caused by the wheels leaving the ground the entire engine and driveline suddenly will over rev because there is nothing holding it back which can cause major damage . A good example of this is the blowover that larry dixon had where his car broke and the wheel went flying into the car park .
What happens is the when the wheels are on the ground they are under load and can only spin as fast as that load allows them to but if the wheels come away from the ground the wheel has no load on it and if the driveline is still spinning then that lack of load will cause it to be like a spring where the wheel now can spin with no restriction and with so much force built up from when it was on the ground it will try to spin faster then what the diff will allow and that is usually why so much load builds up on the wheels studs causing them to share off .
A different thing can also happen if you get too much grip when the diff is trying to move the wheel but the wheel has so much grip that it rips the studs off because the wheel doesnt want to move .
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BrettV
Nitro Member
Actually that isn't what cavitation is at all. From Wikipedia: "Cavitation is defined as the phenomenon of formation of vapour bubbles of a flowing liquid in a region where the pressure of the liquid falls below its vapour pressure." It is the trail of bubbles that come off the tips of propellers (or impellers). Perhaps what you are alluding to is that if the motor over-revs the prop (or impeller) is likely to cavitate.
Yeah apart from hydroplanes I don't go to many boat races , I only said they call it cavitation because when I was at a jet sprint boat race once we were talking about the stress of over reving on an engine when it leaps out of the water and they kept calling it cavitation . But anyway thats not important , what I was trying to say and get across is whats important and I think I explained that part pretty well .
Bob
Nitro Member
Dakin's slicks didn't leave the car until the car made a very hard landing on the top of the retaining wall. Both of them broke off due to that impact.
BrettV
Nitro Member
No problem, you just stirred some old memories from the (little used) ocean engineering part of my degree. See ma I was paying attention in class!
Paul
Nitro Member
Anybody know of any followup effort on this incident by the NHRA?
There is a pretty good model in place to insure driver and spectator safety that NASCAR has put in place to handle situations like this that the NHRA could easily put in place also. Impound parts when something unexpected like this has happened, find some experts to take the best your best shot at figuring out why by examining the parts, and if its reasonable, take steps to insure it can't happen anymore.
Not doing anything is just not right, and saying nothing looks like you're not doing anything. Sorry if this is annoying to some readers, but its lame to keep open the possibility of somebody getting hurt when it likely could be avoided with a little action. NHRA executives appear to be being paid pretty well, and they need to make efforts to take reasonable care in protecting both racers and spectators.
Paul T.
There is a pretty good model in place to insure driver and spectator safety that NASCAR has put in place to handle situations like this that the NHRA could easily put in place also. Impound parts when something unexpected like this has happened, find some experts to take the best your best shot at figuring out why by examining the parts, and if its reasonable, take steps to insure it can't happen anymore.
Not doing anything is just not right, and saying nothing looks like you're not doing anything. Sorry if this is annoying to some readers, but its lame to keep open the possibility of somebody getting hurt when it likely could be avoided with a little action. NHRA executives appear to be being paid pretty well, and they need to make efforts to take reasonable care in protecting both racers and spectators.
Paul T.
Theres not exactly much they can do apart from make sure it wasn't human error , this kind of accident isn't just a drag racing thing . It can happen in anything from kids mini stock cars to nitro drag racing . What happens when a wheel comes off at speed is unavoidable it is just physics . Sure you could make the studs stronger but if by chance one still comes off it is going to do the same thing as I explained in my earlier post .
Here are some examples of wheels coming off , and remember that when you get an out of control spinning wheel if it hits something the way it is spinning will cause it to be more out of control and fly off anywhere .
YouTube - a cars wheel comes off and smashes another car
YouTube - 2008 Coca Cola 600 - Brian Vickers Wheel Hits Camper
YouTube - Wheel Comes Off Car
YouTube - Horrific dragster crash
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Exactly and that is done by doing a Root Cause Analysis. To do that, you must do a thorough investigation, including interviewing the person who installed the wheel, which should of included the method(s) and tool(s) which were used. How accurate was the torque wrench, if one was used. etc. etc. etc. Does anyone here honestly believe all that was done? I have my doubts or else people wouldn't be saying "Oh well stuff just breaks". JMHO.
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none
Nitro Member
So Paul,
Because you haven't heard about it you assume that nobody is doing anything. And that by extention nobody cares?
That's wrong. In the first place NHRA ALWAYS invetigates these events. If there is something conclusive that can be done to make the situation better it is done. Outlawing the ti. studs is a perfect example. After the investigation it was determined that ti. studs should not be used to hold the wheels on so the rule was changed.
Also even if NHRA wasn't looking into it DSR is. Don doesn't scrimp on anything safety related and Don himself came to the top end before the car was on the flatbed. He wanted to know exactly what happened, and then he started looking into what could be done to insure that if it could be prevented from happening in the future it would be.
Alan
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Good grief, I can't believe that this thread still has legs. OK, I'm going to go along with a previous poster and ask that the NHRA cancel the 2009 season until this subject has been thoroughly researched. Maybe all those that are concerned that the NHRA is sitting on their hands, with their heads planted in the sand, should contact Glendora and ask that a "Special Prosecutor" be appointed so that blame can be assessed and the appropriate parties jailed and fined, or just maybe sent to their room without dessert. After that a "Blue Ribbon Committee" of engineers should be enjoined to create "The Unbreakable Wheel Stud", with cost being no object, of course. This should only take about two years and a few million dollars to put this problem to rest. Then, when the 2011 season gets underway, the fans can flock back to the races without fear of ever being attacked by a wayward tire, like is so common right now.
I think that the first engineer that needs to be brought in is John Peters, of Freight Train fame. After all, he already has a whistle and the engineer hat. That could save some important money right upfront. What do you guys think???? What else needs to be done?
Pat
I think that the first engineer that needs to be brought in is John Peters, of Freight Train fame. After all, he already has a whistle and the engineer hat. That could save some important money right upfront. What do you guys think???? What else needs to be done?
Pat
Paul
Nitro Member
Alan, it just doesn't look good when an organization responsible for both driver and spectator safety says nothing after a fundamental component failure occurs, that only through the grace of god didn't get somebody hurt.
The NHRA safety head needs to at least let the public know that they are at least taking steps to find out what happened. Perhaps it was just as simple as the studs weren't torqued properly, but who knows at this point?
Sorry, I know you guys hate reading about criticisms on safety, but this is a pretty fundamental issue that probably either has an easy fix, or maybe no fix it all if it turns out it was a torquing issue.
But not to make a single statement about it makes the NHRA look bad, and they can't afford that in this tough time when attracting sponsors is very difficult.
Paul T.
vegasnitro
Nitro Member
Looks bad to whom?
I have not seen this incident talked about anywhere but this thread. It's not like there was a story on Sportscenter that ended with "Still no comment from NHRA".
I SERIOUSLY doubt prospective sponsors are sitting around going "Well ... we were going to sponsor a funny car ... but since we haven't heard anything about those wheel studs ... we'll take our money elsewhere." Ridiulous.
Outside of us drag racing anoraks (and there are very few of us), nobody cares.
NHRA will let those that need to know what to do. To me, in this case, the silence is not deafening.
none
Nitro Member
Paul
Just for the record, as always I am NOT speaking for the NHRA. But I have been around long enough to know how this works. I also am not arguing with you, just having a discussion.
Do you think NHRA should issue a statement, or call a press confrence every time there as a failure of some type?
What they do is decide what if anything needs to happen and then inform the teams if changes need to be made. DSR would do the same thing. If they found something of a safety matter they would certainly let the other teams know what to look for. Performance and safety are two different things and nobody I know keeps safety secrets.
Alan
Just for the record, as always I am NOT speaking for the NHRA. But I have been around long enough to know how this works. I also am not arguing with you, just having a discussion.
Do you think NHRA should issue a statement, or call a press confrence every time there as a failure of some type?
What they do is decide what if anything needs to happen and then inform the teams if changes need to be made. DSR would do the same thing. If they found something of a safety matter they would certainly let the other teams know what to look for. Performance and safety are two different things and nobody I know keeps safety secrets.
Alan
Jenn
Nitro Member
Is the public going to be called upon to torque the wheels? Is Paul T. in the stands going to be forking over $$$ to investigate the issue and stand over the wheel guy checking his work?
When I buy a pair of studs, any kind of studs, there is a bit of information tucked inside the box dictating torque sequence and torque specs.
If you don't trust the techs who put these cars together, you might want to consider coming to the races in an SFI suit and SNELL approved helmet while you watch. Or put in your back pocket, a fence to keep flyaway objects from reaching you in the stands.
Or, you might want to go back to street racing where there is virtually no regulation into safety equipment, see how that works out for ya.
Nitrohaulic
Nitro Member
Changes were made, i.e. cage shields required, for something that happened one time and killed one person. Had ONE of the errant tire/wheel combos that have come off in the past killed ONE person, I'm convinced wheel stud sizes would have been bumped up already. If it happens in the future and something is changed AFTER someone gets killed? How stupid is that going to look?
I think wheel stud sizes should have been bumped up a notch before cage shields were required. I think driveline coupler splines should shear before wheel studs or wheel centers fail. Why do they have full floating rears? To keep tire/wheel assemblies from coming off? This isn't hard.
Going up from 5/8 to 3/4 would strengthen the stud by how much? The cost new would be how much less than a titanium cage shield?
I'm the last person to advocate rounding off all the corners in life but, we're watching occasional bullets flying around and it seems like we're just waiting for one to connect.
Pro stock and nitro drivers wear different thickness fire suits but have the same size wheel studs?
I think wheel stud sizes should have been bumped up a notch before cage shields were required. I think driveline coupler splines should shear before wheel studs or wheel centers fail. Why do they have full floating rears? To keep tire/wheel assemblies from coming off? This isn't hard.
Going up from 5/8 to 3/4 would strengthen the stud by how much? The cost new would be how much less than a titanium cage shield?
I'm the last person to advocate rounding off all the corners in life but, we're watching occasional bullets flying around and it seems like we're just waiting for one to connect.
Pro stock and nitro drivers wear different thickness fire suits but have the same size wheel studs?
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Draw 3D
Nitro Member
On my MW axles for the Ford 9 inch rear-end, the studs have a .6875 diameter shank that actually drives the wheel, if you go to a .750, it will not fit most rims in use now.
I'm pretty sure that no one that has posted on this topic knows exactly what happened, yet, all kinds of "solutions" are being offered.
