Max Heim wrote:
>
> Your experience illustrates why I was so skeptical of rear discs on a street
> B when the idea was proposed recently.
I have no doubt that a street B would benefit very little from the
addition of rear disk brakes - unless the car was very hot (maybe V8)
and you drove it at speed - and maybe a little less safely than you
should. I would never really consider rear disk brakes for a street B.
In fact, I really wasn't considering rear disk brakes for the track (I
was usually safely outbraking lots of other more poerful cars with my
drum brakes - they would lose me on the straight and I would catch them
through the corners and under brakes). But I really wanted the Limited
Slip Diff and these brakes were almost thrown in for nothing more - they
were hanging on the end of the axle with the difgf I was offered so I
said OK, I'll have them all.
Remember, I am running on soft compound 195/60 tyres on 14" rims. They
can use and benefit from a lot of braking.
> What you need is a
> proportioning valve to dial back the rear braking...
Trust me - I am going to be hunting the better/perfect balance (after I
get my proper tyres on the back).
>
> My understanding was that a limited slip diff would promote understeer,
> unless you had gobs of power. That seems to be what occurred when you
> understeered straight off the track.
>
> So now you seem to have a combination of power-on understeer and rear
> lock-up under braking -- that doesn't sound like the optimum setup for
> predictable handling (to say the least).
Hey, there was no way I was going to know what was going to happen,
exactly, until I put them to the test (remember, I asked here first) but
there was a combination of factors involved (including learning how to
drive the new setup) and I believe they are all solvable with work on
the current setup.
>
> It looks like you are faced wth another round of upgrades: vastly improved
> front braking, and greatly increased horsepower. Or, I suppose you could
> just chuck it and go back to where you were. You might want to talk to
> fellow racers with similar setups (if there are any) to see if they have any
> suggestions.
The bar-talk about my problems started shortly after the day finished,
trust me. But I generally just had most of thoughts re-affirmed. I
needed, however, some external verification as to what happened on each
difficulty because from inside the car I wasn't always sure. I don't
need more front brakes - the slotted/grooved disks I have now are great.
But hey, how else would I have experienced a 100mph spin (and survived
to tell the tale) unless I did this sport for a hobby - none of my
workmates have! And it seems I entertained the crowd somewhat on a
generally lacklustre day for actual performances :-)
--
Eric
'68MGB MkII
Adelaide, South Australia
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