All,
Bob Lang sent me his thoughts on different rear hubs
for IRS Triumphs, and forgot to cc the List. Well, here
it is.....
Hi Shane.
> Near as I can figure, they're not available anymore.
The parts were offered by SNG Barratt, and they sold out the Triumph line
of parts to Moss Europe. I asked the Moss folks on two seperate occasions
if they intended to have those parts available - they said "no". Not sure
who the supplier actually was, but the axles (and CV joints) appeared to
"adapted" to fit the TR. And the axle stub was either adapted Triumph or
a new piece manufactured from a billet.
At any rate, the option appears to be unavailable.
> If you have a moment, could you tell
> me a little something about the Corvair arrangement?
I'll try.
Group 44 and the West Coast folks (Kas Kastner et al) had noticed that
the stock axles failed pretty regularly. In fact, if you look in the TR6
Competition Preparation Manual, and read if closely, you'll see that they
suggest swapping the axles out from time-to-time. I even recall something
about swapping them out every 8 races (or was it 4)... anyway - an
expensive proposition - even when the parts were "readily available".
Anyone that had a Triumph back then understands the quote marks.
At any rate, Brian Fuerstenau (sp??) or one of the others came up with a
smashing good idea. The Corvair IRS axle stub is quite a lot beefier than
the Triumph piece. All you had to do was make a new hub carrier out of
aluminium, use some slightly different bearings (diff ID's for the axle)
and then do "a few more things" to the axles and adapt to a beefier U-joint.
The extreme case is to swap in axles from another source - the Gp44 TR6
vintage racer that most of us in the eastern USofA are familiar with
reportedly uses axles from a Mercedes Benz 450 SL. However, I'm told that
the stock axles are okay up to and a bit above 200 HP, which probably is a
number that the vast majority of the Triumphs list will _never_ see on
their TR6's. So you don't have to go too crazy on this thing.
An added attraction of the Corvair conversion is that the lug pattern is
4 on 4.5" - just like our big TR's. Yippeee! You don't have to get new
wheels.
Lots of folks that have raced (or currently race) IRS Triumphs in the
USofA use this setup. I have a copy of a copy of the plan from the Gp44
garage somewhere in my house of the dimensions of the hub carrier. A
compentent machinist should be able to mill you out a set - but I have no
idea of what alloy to use or anything like that. The kicker is that the
setup appears to be basically bullet-proof, with no failures reported
that I'm aware of. And this is from serious SCCA racer types. Should way
more than adequate for my simple needs. ;-)
So, I'm about to try to track down a certain mid-west TR6 racer who
apparently makes these things from time-to-time and get me a set so I don't
have to worry about my axles anymore.
If you have a street TR6, this sort of modification is "wicked overkill",
but if I get more info, I will post to the list about it.
Bottom line - it'll cost about $1000 US to adapt, and it's not a "bolt in".
> I'm
> about to go through the rear-end of Rags, and wanted to
> get a little "creative".
Well, if you can get a hub carrier made, you could adapt to just about
anything. If you find a hub that has a 4 on 4.5" bolt pattern - even better!
Gotta find that drawing of the hub carrier I have... _somewhere_.
> Cheers,
> Shane
regards,
rml
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