i have some thoughts that i think could be helpful for others thinking about going with a brake pad that is marketed as 'high performance' based on my experience daily driving and tracking a pad (brembo sport pads) marketed by tire rack as 'autoX/track'.. ie supposedly similar to hawk hp+ pads
1) most of the time my 'autoX/track' 'performance' pads are doing squat. they are way too cold on the street to notice any of the 'performance' attributes such as aggressive initial bite or pad fade resistance or compression resistance (ie don't waste money on a performance pad unless you will actually be hammering on your brakes at a track or in the mountains)
2) even if you bed in your brakes correctly, you will need to rebed them before doing any serious performance driving... the performance pads stay cold (abrasive) so they take off the transfer layer you put down during bed in.. i didn't realize this before, and that is why i got brake shudder in the first place. in the future before i track my car, i will repeat the bed in procedure on the way to the track to help avoid shudder (ie don't just go to the track and start hammering on your brakes without rebedding them)
3) it might be better to keep an OE pad for street use and a hardcore track pad for track use.. (ie there's really no way for a pad to stay usable on the street and temp resistant for the track. the pads i'm using are definitely rougher on the rotors than OE pads when cold and a real track pad would be like a portable lathe when cold.. i may have overheated these 'dual purpose' pads on the track without using r compounds)
4) it really seems like all 'performance' pads dust like a biatch.. when i get these pads good and hot.. and i am really using them.. i am generating dust like crazy.. (ie if a pad is marketed at 'performance' AND 'dusts less' be wary of teh snake oil salesman)
hope that helps!
even if you bed in your brakes correctly............
Explain how to do this and what it means please.
meford4u,Oct 16 2007, 10:44 PM Wrote:even if you bed in your brakes correctly............
Explain how to do this and what it means please.
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these guys can explain it better than i ever could
theory:
http://www.stoptech.com/tech_info/wp_bedintheory.shtml
procedure:
http://www.stoptech.com/tech_info/wp_bedinstock.shtml
cliff notes:
"the objective of the bed-in process is to deposit an even layer of brake pad material, or transfer layer "
the actual process of bedding in street brake pads is to do 10-15 stops at about 90% of the braking effort needed to engage ABS in the dry or lock up the tires. that's it. nothing to it
what it means takes longer to cliff notes
when the pads are hot they are in 'adherent friction' mode (eats pad) when they are cold they are in 'abrasive friction' mode (eats rotors). in adherent friction a layer of pad material is deposited. at first it is deposited on the rotor, and then after the transfer layer is the surface that contacts the pad. if there is any unevenness in the transfer layer you will feel that as 'shimmy' or 'shudder' in the brake pedal or steering wheel. almost all of the time when people say a 'rotor is warped' really what they should be saying is 'there are uneven pad deposits causing vibration'
so if brake pads are not bed in correctly and you take it to the track and start hammering on the brakes you might get an uneven deposits (instead of a controlled initial depositing that you would get if you intentionally bed in the brakes)
or if you over heat street pads the material will come off in chunks (i got a little bit of this too) and you will actually see the imprint of the pad on the rotor. either way.. same thing.. you will get brake shudder
that whole abrasive vs adhesive friction thing on the stoptech site is the main reason why i think street performance pads don't seem like that good of a deal. you have to trade off rotor wear and low temp stopping to get the high temp resistance from chunking.. so when ppl say hawk blues aren't good for the street it is because they will be portable lathes that chew up your rotors all the time because they would never get hot from street use to become adherent
i sort of semi rambled there your best bet is probably to read the stop tech site =)
I think I may go back to stock for my next brake change.
I am currently on Brembo blanks and Hawk HPS pads. These produce almost no dust whatsoever. The pads have produced a concentric ring grooves pattern on my rotors so I may not be getting them hot enough. I tend to have a light touch on my brakes as I hardly ever slam them (I don't tailgate.)
I find that this setup when wet and cold are not that great. The initial stop in wet weather tends to be pretty hairy. The brakes have to be good and hot for good performance.
I noticed something similar with my KVR brakes...
on a long trip, if I suddenly had to slam on the brakes for whatever reason, the stopping distance would be horrible -- tho consecutive stops after that would be alright.
I'd have to concur in that the Hawk HP+ I have are kinda mushy when stone cold, but one good stop and they're ready to rock (and since I have to play merry go round in my parking lot I always get at least three stops in before I hit the streets)
NefCanuck
re the hawk hps in the wet.. i wonder if that is just water building up between the pad and the rotor? i had hawk hps on a bunch of cars and i found them to be very stock like in all aspects except less dusting.. never had a problem in the wet.. maybe even with the stockers you might have had that issue too ? do you only have it when you are driving for a while on the highway in the rain without pressing on the brake?
nef how hard do you drive on the hp+? have you tracked them? if they can actually take track use without overheating i might try them next time.. i'm trying find ways not pay $250/pair for hawk blues
naz,Oct 18 2007, 01:46 PM Wrote:re the hawk hps in the wet.. i wonder if that is just water building up between the pad and the rotor? i had hawk hps on a bunch of cars and i found them to be very stock like in all aspects except less dusting.. never had a problem in the wet.. maybe even with the stockers you might have had that issue too ? do you only have it when you are driving for a while on the highway in the rain without pressing on the brake?
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Exactly.
From work I have a short jaunt to the highway where I may not even have to hit the brakes once and then I am only on the highway for about 8 km where I don't usually run into traffic. My first real brake application would in most cases be coming off highway speed to the traffic light at the end of the exit ramp. In the wet I usually brake alot earlier because it almost feels like I have no brakes until all of the water is evaporated with the heat build up.
naz,Oct 18 2007, 01:46 PM Wrote:nef how hard do you drive on the hp+? have you tracked them? if they can actually take track use without overheating i might try them next time.. i'm trying find ways not pay $250/pair for hawk blues
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I had paid and was planning on going to the SVTOA track weekend this year but the death of my father had scotched that :(
I've had to slam 'em a few times owing to meatheads on the roads in the few months I've had 'em on. Car hauls down like a boat anchor was on its arse and no ABS engagement ;)
NefCanuck
NefCanuck,Oct 19 2007, 02:54 AM Wrote:I've had to slam 'em a few times owing to meatheads on the roads in the few months I've had 'em on. Car hauls down like a boat anchor was on its arse and no ABS engagement ;)
NefCanuck
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no abs engagement under hard braking is a function of your tires not the brake setup.....
pls let me when you track them.. if you can overheat them too then that means i have to get blues for sure :(
naz,Oct 19 2007, 01:57 AM Wrote:NefCanuck,Oct 19 2007, 02:54 AM Wrote:I've had to slam 'em a few times owing to meatheads on the roads in the few months I've had 'em on. Car hauls down like a boat anchor was on its arse and no ABS engagement ;)
NefCanuck
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no abs engagement under hard braking is a function of your tires not the brake setup.....
pls let me when you track them.. if you can overheat them too then that means i have to get blues for sure :(
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Will do, don't think there are any track days left this season though :iono:
I will be going to the SVTOA clinic next year, no way my luck is that bad that it happens twice in a row <_<
NefCanuck