[urq] bomb test variation with S4 brakes?

[Renneisen, Eric 475]

Martin wrote:
> Show of hands to all who have done G60 upgrade (or 4 piston
callipers), 
> did not change MC and still have great brakes (i.e. very little pedal
travel)??

I don't really consider minor variations in pedal travel to be
indicative of the 
quality of braking--consistency and modulation are far more important.
That 
said, both my '85 and current '86 had G60s and stock MC when I got them.

The brakes worked fine (not "great"), but the pedal travel WAS slightly
longer.  
This makes sense because the G60 calipers have an effective piston
diameter 
(equivalent single piston) of 60mm, hence the name.  Similarly, the
stock urq 
caliper (G54) is 54mm.

Currently, I'm running Boxster 4-piston calipers.  My calculations show
that 
the effective single-piston diameter of these is 53.8mm, very close to
the 
stock 54mm.  My pedal travel is noticeably shorter than with the G60s, 
which makes heel & toe action MUCH easier.  In this respect, pedal
travel 
does directly impact my opinion of brake quality.

FYI, even the Porsche 993t (big reds) and 996t calipers have an
effective 
single piston diameter of about 57mm, proving yet again that it's not
the size 
that counts, it's how you use it.  ;^)

Eric R.
'86 urq
'93 S4

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