Discussion
We had an interesting discussion about this on the Team3S email list, where there were advocates and doubters. First, an exchange of ideas, then some new and valuable information from one of our Team3S member-vendors, who's an expert in brake technology:
Q: Should Porterfield R4 and/or R4S brake pads be BBQed before use? The coals
are hot! :-)
A: Absolutely! But you don't want them so close to the coals that you ignite
them! You want to bake them at high heat to "outgas" them. Yes, they will
still smoke and stink a lot - you'll probably piss off a few neighbors. :-)
But it makes all the difference in the world at the track... For one thing,
they don't have to warm up as much to work at optimum, as all brakes do. And
they won't stink as much after a few hard stops (and make you think you broke
something). We didn't BBQ the previous set (R4S), and at the track we could
see them smoking and stinking all over the place, especially when we finished
the first few runs and came back to the pits. Fiercely AWful smell... But we
BBQ'd this most recent set and they stopped tight right from the first run.
No smoke, no smell, no muss, no fuss, no bother... :-)
Q: FWIW --- I tried the BBQ on one set of pads a year or so ago and found
that when finished the surface was very uneven, as much as 1/16" or
more. I sanded them down to provide a flat surface although I'm sure that
a few laps would have accomplished the same thing.
A: That's exactly the point! You *can* do it at the track and suffer the smell
and partial brake capacity as the brakes get rid of the impurities OR you can
do it in advance and not have to make the first couple of runs choking on
brake smoke. Perhaps you didn't do a *g-r-a-d-u-a-l* warmup and cooldown when
you did the BBQ? As I pointed out to Jim M, you want to bake them at high
temperature, not put them over the hottest part of the coals to burn. Then
after an hour or so, turn off the heat and leave them in the BBQ after it's
off (as the instructions point out) to cool down slowly (I leave mine
overnight). Fast heating or cooling would no doubt warp the pads and make
them uneven. And I get max performance out of new brakes even on their first
track run with BBQ-ing - I don't get that when I don't BBQ. I get fade and
smoke until they are outgassed, then by maybe the 3rd run I get max
performance...
Q: There have been claims of extended life as a result of barbequeing but I find
that hard to believe --- If Porterfield could get extended use from pads by
heat cycling them I'm sure they would do it. A BBQ may get the pads up to 600º
or 700º while a 20 minute track session may get them up to 1000º. I think it
more a matter of maybe doing some prep work in advance and making a stink at
home rather than at the track. The last few times I've
done the bedding on the way to the track on some open stretches of road.
A: Why would PF want them to last longer? Why not let us waste material and
weaken the pads (so we have to replace them sooner) with rapid heating and
cooling at the track? When I BBQ, I don't have to bed the brakes - they
aren't uneven and they work perfectly first time out. You should try a SLOW
heatup/cooldown sequence in the BBQ and see if you feel differently. For me,
BBQing is much better, and the brakes seem to last longer. I'm copying this
post to Andie Lin (formerly at Carbotech, now with his own company) - perhaps
he can do a test for us with his new pads, with- and without a BBQ procedure.
He runs his NSX at the track and can give us "butt dyno" data, plus he has the
testing equipment to either debunk a myth or prove the validity of BBQ-ing
brake pads once and for all.
Fortunately, Andie Lin *did* respond, and he gave us this primer on the BBQ question:
Interesting and somewhat amusing... BBQ-ing bake pads. But, in the final
analysis, it works to varying degrees, depending on the compound and
manufacturing technique.
Typically, a high-resin and binder brake pad compound will require more
outgassing. Back in the day (when I was in diapers), brake friction
compound technology wasn't very well developed (not to the level it is
today), and a much higher resin and binder content was used, than was
necessary. This resulted in the need for outgassing new pads before
subjecting them to race/aggressive conditions/use. Nowadays, not only is
the resin and binder content kept to the bare necessary minimum (less is
actually better, to a point...provides a better bond strength to the backing
plate for integrally molded pads), but pads are typically outgassed at the
factory as part of the manufacturing process... similar to what you are
trying to achieve by sticking them in the BBQ.
Based on what I have done and seen, you will notice an improvement in wear,
as well as a shortened bedding in time if you bake your pads... But it must
be done gradually. I feel that an open flame BBQ grill will heat-shock a
pad compound, and possibly compromise structural integrity. If you want to
heat-treat your brake pads before use, the following recommended
times/temperatures can be used as a starting point:
High-Performance Street Pads (Axxis Ultimate, Hawk HPS, etc.)
1 hour @ 200F
4-5 hours @ 450F
*allow to cool off overnight to room temperature
Track Pads (Ferodo DS3000, PFC 01, PFC 93, Pagid Orange, etc.)
1 hour @ 200F
2-3 hours @ 400F
4 hours @ 600F
*allow to cool off overnight to room temperature
Most ovens
increase heat at a very gradual rate, so you don't need to worry
about heat-shocking the pad. Same for cooling them down...just let them sit
in the oven until they cool...don't take them out and dunk them in water,
etc. Basically, you need an industrial convection oven to do it "right", but a
standard house oven works: Two notes: 1) Put them in with the pad material
facing UP. 2) It will stink your house up if your oven does not have an
integrated vent.
This being said, a proper "bedding" procedure requires heat AND pressure AND
abrasive friction...basically, they have to be used on the car. Further, I
don't believe in "dyno bedding" of pads...as a dynamometer will maintain
constant torque, while in a real-world situation, torque requirements change
as the car decelerates. Heat-treating your pads will result, primarily, in
less initial dusting (and thus wear), and will hasten the bedding procedure.
This does not mean you can just put the heat-treated pads on the car and
start using them as you would under race/track conditions (i.e., you can't
install them and beat them from lap 1). It simply means they will bed in
faster, and thus last longer. Compound wear on a new brake pad is 20-40%
faster during the bedding procedure than a pad that is fully bedded. If you
heat-treat the pads before installing them, you will improve wear during the
bedding procedure to perhaps 10-15%.
Sounds hokie, but it works. In the case of certain compounds,
heat-treating will also improve the stopping power (i.e. braking torque),
lower the dust level (i.e. due to slower wear), and reduce noise. This is
the case with some street compounds. I can't list which ones they are due
to the nature of my relationship with the manufacturers of these compounds
(i.e. they consider it an alteration of their product, and do not condone
it - and I respect that).
DISCLAIMER: I am not endorsing this procedure by the end-user. I am simply
concurring that it *does* work. Hope this helps...
--- Andie W. Lin
Cobalt Friction Technologies
1013 N. Federal Highway, Fort Lauderdale, FL 33304
Office: 954.828.1512 :: Fax: 954.828.1517
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