I Broke Another... racing story

[roccit_53 at scirocco.cs.uoguelph.ca (C Boyko)]

Well heck! Glad it didn't happen here or you might have been forced to
leave the car in my garage <rubs hands together>

Now here's one, what would the effect of the rain be? Would this add to the
problem as you'd still be heating the friction materials, but the rain
would knock the temp back down a LOT faster. Just wondering if TDN
accelerated the process maybe? Not that you ran into rain here, mind you :)

Glad YOU're okay, and that you guided the car safely out of the way of the
others, and that there were no fire extinguishers involved!
Cathy

On 10:57 pm 09/03/06 Ben <vwtype53@yahoo.com> wrote:
> <long...well, for me at least!>
>
>
> Well, this weekend was not so nice to my mk1...
>
> As most of you know, I road race my '80 Scirocco.  Amazingly enough,
> I am still using many stock components, like A1 hubs, wheel bearings,
> ball joints, axles, 020 trans, etc.  There is no question that I am
> pushing my luck with some of these components.  I am pushing quite a
> few more horses through the drivetrain than the little 1.6 did back
> in 1980.  I am also generating a lot more grip with my 205-width race
> tires... oh, and I'm braking, and generating a LOT more heat, than
> the VW engineers ever imagined that mk1 chassis could.  Needless to
> say, things are being stressed and have a tendancy to break now and
> then.  Now and then was today.
>
> For the second time in 3 years I have succeeded in breaking a hub!
> Yep, the hub sheared at the point where the neck enters the wheel
> bearing.  So basically my wheel was being held in place only by the
> axle and axle nut!  I consider myself lucky that my wheel stayed in
> place (for the most part) as I came to a stop.  I was exiting a turn
> and applied throttle only to have the engine rev freely to redline. 
> I thought at first my clutch had just exploded or possibly the trans
> pinion shaft sheared all it's teeth... I ended up coasting down the
> straight and pulled into the grass to wait for the session to
> end...they hooked me up and towed me back to the pit area where I
> pulled things apart... I hate getting towed back into a sea of
> Porsche's... not that they don't break too (more than one Porsche was
> towed this weekend), but it doesn't help for them to see the vw being
> towed back.  It's happened more than once to me over the years. Then
> again, I try to make up for it when I keep up with most of them on the
> track...   :)
>
> I think that the hub failure was due to a combination of the heat
> cycles from braking and the load cycles from each and every turn I
> make on the track.  The heat generated from my brakes while slowing
> from 120mph down to around 70mph (in about 2 seconds or less) is
> intense.  Then add in all the smaller turns throughout the track and
> you have some serious heat building... not only in the rotor and pad,
> but surrounding knuckle and hub assembly.  And doing this for 25
> minutes straight, 3 times a day for a 2-day weekend, and several
> times a year... yeah, it's a lot of heat cycling.
>
> Obviously, the biggest factor here is that I am racing on sticky
> tires and generating a lot of grip... which puts a lot more load on
> the hub/bearing assembly.  One trick that the A1 race guys use that
> I've read is to over-torque the axle nut.  The axle nut sandwiches the
> hub against the CV and will help reduce some of this stress.  I read
> of guys using massive breaker bars to get the torque on that nut to
> over 300 ft-lbs!  Anyone heard about this?
>
> Well, just wanted to share my experience.  A friend helped me get my
> car home, so no worries there... I'll be repacing the hub and bearing
> soon.
>
> At this point, I think my only option for upgrading would be using
> the A2 knuckle and bearing. But then I would need to use the A2
> strut/shock housing and ball joints I suspect.  Not sure if the A1
> tie rod end would work on the A2 knuckle... has anyone upgraded a rocco
> to A2/A3 front suspension components?
>
> Tighten that axle nut!!  ;)
>
>
>
> Ben Harder
> 1980 Scirocco
> 1997 Jetta GLX
>
> http://www.geocities.com/vwtype53/
>
> __________________________________________________
> Do You Yahoo!?
> Tired of spam?  Yahoo! Mail has the best spam protection around
> http://mail.yahoo.com
>
> _______________________________________________
> Scirocco-l mailing list
> Scirocco-l@scirocco.org
> http://neubayern.net/mailman/listinfo/scirocco-l