Radial thrust on the axle flanges is the cause of the failure. The first axle was maybe 5 races old (not sure with the rain outs) the second axle was discovered after it's second night of use. The axles were in fact stock GM units from slavaged cars. The bearing areas were inspected and polished prior to installation.
The failure eminates from the stress riser created at the axle flange to drum pilot diameter junction. This can be discerned by inspection of the shore line indications which also prove the mode of failure is fatigue caused by an overloading of the axle stud flange in a axial direction.
It would suggest the axles is being stressed well beyond it's designed safety factor, thereby concluding stock axles are not the safest option at these speeds using the tires we use. This would necessitate the need to use alternative parts of a better quality and design to reduce if not eliminate the above mentioned condition from occuring.
In short the stock GM axles are not safe for racing at these speeds due to lateral force generated during cornering.
Of course I'm only guessing 😉
And I think the tracks decision is a sound although I disagree basing it on cost but rather think driver and fan safety is the issue at hand 🙂
So your listed 2 failures were with stock GM axles.
I know that alot of teams are running after market axles and you'll likely find that as the norm.
I'd suggest before people dive into a floater 9" that after market axles maybe the quickest, lightest (as in weight savings 100#) and cost effective.
I know the Mark William axles I had in the 71 SS ran about $800CDN for the pair at about $1.20 exchange rate, and are likely the most expensive, but there is also Bear, Moser and Strange to check out.
Give Matt on the 77 a call his axles are aftermarket and were not a bad price, for the piece of mind and safety.
when it comes down to it, if an axle is going to break it going to break, regardless if its a high dollar one or a lower cost one. axles dont just break for no reason, we have had the same axles in the 55 street stock since we started and never have had an axle break or anything at all (knock on wood) guess we are just lucky, and yes they are not expensive axles, stock oem cheap axles. my only conclusion would be that something else (rear end wise) is causing these axles to break, some people seem to have no issues others seem to have issues, and i really dont think it is beacuse of how much you have spent on such axle be it oem or a racing application axle.
as far as 16v bats, the rules say 12v system plain and simple, but once again we see the tech groups "clique" on who can get away with what, not saying jason isnt deserving of the championship he was consistant and that won him the championship not the 16v system but it clearly says 12v system in the rules, and they let him get away with it, its never a problem till the next guy gets it and then all hell breaks loose.
overall was a good meeting (werent all crammed into a small dang room like the first one i went to), first one ive been to for 3 years now, got the questions i had answered looking forward to april 17th now.
Give Matt on the 77 a call his axles are aftermarket and were not a bad price, for the piece of mind and safety.
You can PM him here. He's Laker77. Or look up London Drive Systems.
Jim bought a new set of aftermarket axles to set up new axles along with some other goodies just at the end of last season....and before the rule for the 9" floater came out.... :'(