[Fot] TR4 axle shafts

[fubog1]

Just a few thoughts on the TR raxdiscussion, based on my observations over the
years...
Obviously the problems are largely dueto the nature of the design, a live
axle, not really ideal forracing, and the components, again, not made for
racing stresses.Since we have to keep the original design, going by the rules,
thatcan't be changed.
The axle shaft, taper & key issueshave been discussed.
The other failure mode is that of thewheel hub, which can crack
circumferentially at the inside corner ofthe wheel flange face and the drum
locating boss, down at about a 45degree angle through to the inside corner of
the seal journal andinside of the hub. These inside corners don't have good
radii and arepretty rough, and the little weep hole is another stress raiser,
andthe cross-section isn't that impressive to begin with. The
flange/hubobviously has a lot of lateral load on it from cornering forces
butalso the heavy load that is applied when the hub is removed forinspection.
I suspect that these cracks are sometimes initiallycaused during the hub
removal, since the factory tool pulls on theflange and puts all of that load
through it to the center of the hub.A good crack check will show it but it
just adds to the potential forfailure of the stock components.
The bSouthwickb conversion retainsthe original (poor) design, live vs
floating axles, and eliminatesall of the known failure points. It offers no
performance advantageat all. Since one of the main objectives of the rules
makers andsanctioning bodies is to allow us to race safely, I would think
thatthey would encourage the conversion...
Glen







-----Original Message-----
From: MadMarx <tr4racing at googlemail.com>
To: fot <fot at autox.team.net>
Sent: Mon, Jan 20, 2014 5:12 pm
Subject: Re: [Fot] TR4 axle shafts


Ken,

I had this talk with the tech people of the ASN.
Answer:
"A axle upgrade in this way is an advantage in performance and not allowed.
You can run harder on curbs than the car without upgrade and might gain
speed from it. Not granted."
Then I came up with safety issues.
Answer:
"You choose your race car. If your car is not suitable for racing, it's your
problem. Where should it end? One car has small brakes, other ones have soft
wishbones and so on. You have to run it as it is."

So the only thing I can do is to change the shaft.

Cheers
Chris