Re: Front Rotors and Pads

[smarinel@Flint.Mines.Colorado.edu (Steve Marinello)]

>Steve Marinello sez:
>> I have Repco Metal Masters on an '83 quattro coupe. As you'd expect, they
>> are not the best until they heat up a little.  They were great at the
>> quattro club's Second Creek Raceway outing in Denver (last June), at least
>> until the rest of the brake system went "soft" while I was trying to keep
>> up with a modified 300+ HP S4 from Dallas.  On the coupe, the dust was
>> dramaticaly reduced from the OEM pads, initial cold weather braking
>> suffered ever so slightly, and "sporting" performance was dramatically
>> improved.  I've run Metal Masters on modified Fiats, Alfas and Triumphs
>> with only good results, especially when you get "sporting".
>
>Metal Masters are Ferrodo DS-11 compound, a compound designed originally for
>heavy GTP cars (it also happens to be the most winning compound in GTP).  It
>likes/needs to be hot for optimum performance.  DS-11 also tends to dump lots
>of heat into the brake fluid (the pads run very hot), but that depends on the
>brake manufacturers' choice of backing, and on caliper piston heat shields,
>etc.
>DS-11 will work better if properly "bedded" when first used; DS-11 pads are
>subject to "green fade" though glazed DS-11 pads will work fine on the street.
>Because of the "gassy" nature of DS-11, it will also benefit from a fire break
>milled into the rotor, or cross-drilled rotors.
>
>I'm not surprised with the performance on Fiats et al; DS-11 is really only
>useful on heavy and fast cars.
>
>For racing use, DS-11 causes extreme rotor wear, though this is probably not
>much of a consideration for street and occaisional track use.
>
>-frank
>-- 
>fhd@interport.net  | [M]athematics is not the study of intangible Platonic
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>1 718 746 7061     |    --  Saunders MacLane

To add to the info Frank has provided...you should be aware that the "cold"
performance of the MM's/Ferodos (sorry Frank, should have mentioned the
compound) will be slightly less than OEM, but that the "warm" and "hot"
performance is drastically improved.  In fact, some people don't seem to
feel that there is much degradation in "cold" performance and that it is
only in comparison to the improved "warm" performance that the pads have
any negative effect.  

Also, Frank is right about the rotor wear; in racing it's significant, but
on the street it's not too noticeable.  Comparing a modified 1608 cc FIAT
124 Coupe with MM's vs. a modified 1756 cc 124 Spider w/o; in "racing" over
Coldwater Canyon (during those younger, crazier days with much less
traffic) the Coupe got better and better as we ran, while the Spider was
loosing it with burning/smoking pads by the end of the downhill...and the
rotors on the Spider needed replacement before the Coupe's, which saw much
more sporting driving while carrying more weight and more horsepower.  So,
on the street and occasional track I'd say that driving/braking style
probably will effect rotor wear more than the pads.

Steve