PAGID Tech info
PAGID Friction Graph
Graph shows friction vs temperature. PAGID materials are very linear as far
as rubbing speed and line pressure is concerned. Since the coefficient of
friction is related among other things to the brake disc material we do not
show friction levels in this graph. It is only considered to show the
difference among the Pagid compounds.
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PAGID Friction Compounds
PAGID racing compounds are complex formulations with very high content of
ceramic materials. All Pagid materials are asbestos free. The difference to
competitor’s ‘metallic’ compounds is the superior thermal insulation and the
higher heat resistance of ceramic compared to iron. Ceramic has, to the
contrary of iron, very low heat conductivity. Consequently less disc (rotor)
temperature goes through the pad into the caliper. We measured up to 60°C
(140°F) less caliper temperatures with PAGID pads vs competitor’s pads. This
is very crucial when it comes to brake fluid boiling.
PAGID friction compounds, especially the color-coded yellow endurance
materials, have a very low wear rate and
are extremely discs friendly. This fact is proven by numerous race wins in
24 hour races world-wide.
Brake modulation and pedal feel with PAGID pads are excellent. Consequently
it is not only less likely to get (tire) flat spots but also drivability is
better.
PAGID Steel Backing Plate Design
PAGID uses a unique and patented system to ensure the friction material does
not delaminate from the steel backing plate. The friction material is
attached to the backing plate in two ways, adhesive bonding and mechanical
retention. The mechanical retention (patented) is accomplished by inserting
‘brass torpedoes’ (studs) -which are welded onto the steel backing plate –
deep into the friction material. The ‘brass torpedoes’ do not harm the brake
disc (rotor).
PAGID is the only race pad that features a retention system which not only
connects the steel backing plate with the under-layer (adhesive bonding) but
also with the friction material itself.
It has turned out that this system, invented in the first place only for
racing, has become also the best retention system for heavy truck and bus
disc brake applications.
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PAGID Race Pad Fitting
Instructions
The new brake pads must move freely in their guides. If necessary remove
paint from the contact faces. Delayed release and taper wear can occur if
pads do not have enough clearance.
The outer radius of the friction material must align with the brake disc’s
outer radius. Especially with custom made uprights (knuckles) or custom made
caliper mounting brackets very often pads do not align properly with the
brake disc. It is advisable to place a note at the steering wheel to let the
driver know new pads had been installed.
Never lay hot pads up side down i.e. with the friction material onto
the ground unless you throw them away anyway. Asphalt, rubber, oil etc. can
melt into the friction material.
PAGID Racing Brake Pad Bedding
If pads do not get bedded properly and / or used to hard right out of the
box will likely lead to pad glazing. Pad glazing is a condition where the
resins in the pad crystallize on both, the pad friction surface and the
brake disc surface, resulting in poor stopping performance, brake judder and
vibrations.
Also rapidly escaping volatile elements and moisture from the resin would
seek an immediate escape route out of the friction compound, creating small
fissures that would lead shortly to cracking and chunking.
Heat Cracks in Racing Brake Pads and Discs
Multiple small heat cracks (hairline cracks) are normal and accepted for
this type of use. Heat cracks on brake discs must not reach to the outer or
inner edge of the disc.
Racing Brake Pads and Humidity
When washing the car we recommend removing race brake pads or driving the
car after washing and apply the brakes a few times in order to dry the brake
pads. Water and even humidity of the air can slightly alter the friction
behavior of racing brake pads. Some pro race teams use “storage” or
“transport” pads and store the real race pads in a Zip-Lock bag until their
next race.
Avoiding Brake Judder
During bedding and shortly after, some judder is quite normal but should
disappear after 5 to 10 laps. Changing back and forth between two
incompatible friction materials (e.g. racing brake pads of different brands
or street pads) can cause uneven build-up of pad material on the disc
surface and can consequently lead to brake judder. Judder is the result of a
thickness variation in pad buildup on the disc surface. Brake judder can be
from a barely noticeable vibration to a violent judder. When you install
Pagid race pads on top of a layer of an incompatible pad material, bedding
might take much longer or in worst case won't work at all. It can also
result in sub-optimal brake performance.
Another reason for uneven pad transfer is called 'imprinting'. After coming
to a complete stop with hot brakes (in the pits or after a spin), do not
keep your foot on the brake pedal. The hot pads can leave a deposit behind
that in turn again can cause judder and vibrations.
Bigger vs Smaller Pad
A larger friction surface will not improve stopping power. The amount of
pressure applied, coefficient of friction and the disc diameter determine
stopping force. A bigger pad does not apply more pressure, only the same
pressure over a bigger area. The size of the pad matters in terms of heat
capacity and wear rate. A larger pad will absorb more initial heat and has
better wear characteristics.
Pad Fade vs Brake Fluid Fade
1.) pad fade
When the temperature at the interface between the pad and the disc exceeds
the thermal capacity of the pad, the pad loses friction capability mainly
due to out-gassing of binder (matrix) materials in the pad compound. The
brake pedal remains firm and solid but the car will not stop no matter how
hard you push on the pedal. The first indication is a distinctive smell, a
signal to back off. Solutions: better cooling, higher mass brake discs size
and vane configuration or higher heat range pad compound.
2.) fluid fade
Boiling brake fluid develops gas bubbles in the calipers. The brake pedal
becomes soft and pedal travel increases (because gas is compressible). One
can still stop the car by pumping the pedal but efficient modulation is gone.
This is a gradual process with advanced warning. The damaged fluid must be
completely replaced. Correcting the problem is improved cooling and / or may
only require new or higher grade racing brake fluid. The importance of
keeping fresh brake fluid in the system and regular bleeding (before every
session) cannot be overstressed.
Watch The Temps!
It is highly recommended that brake temperatures are being monitored. Three
temperature brake paints or similar products should be used. Ideally, the
green paint (430°C / 806°F) should be completely oxidized (turns white), the
orange paint (560°C / 1040°F) should be symmetrically beginning to oxidize
and the red paint (610°C / 1130°F) should be un-touched or change only
slightly.
Caliper temperatures can be monitored with temperature strips.
Checking the temperatures in the pit lane with a thermometer is a good way
to oversee brake bias.
Disclaimer of Warranty
PAGID racing brake pads are developed for high performance events.
Motorsport is dangerous. PAGID racing brake pads are sold without warranty
expressed or implied. No warrant or representation is made as to this
product’s ability to protect the user from injury or death. The user assumes
that risk.
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