Brake honesty

[Bruce Fielding]

I should point out that this was on a Mk1 165, so the speeds to be reduced were slighly lower.

As I might have mentionsed, I know naff all about brakes... don't have a clue about the specifics of my brakes -  I have alcon fronts and competition rears - factory standard everything.

[Driver]

Bruce if you were going that long and track days were part of it as well then you should've changed out the pads. I would've sacrificed brake pad life for one with better stopping power (better operating range)  in a heartbeat. You should've gone softer compound.  I think the answer will ultimately be a really soft compound for street driving and a more aggressive one for track use and people will just have to learn how to swap pads. It's not difficult.

[DarthChicken]

I'm honestly not sure what is available for alcons.  On my personal (stoptech) setup, I run carbotech panther xps on the track, and axxis ultimates on the street.

For the wilwoods, I used D pads on the street, and E on the track.  I know of some that have used the "A" on the track, but these same folks always seem to crack their rotors too.  

Here's some reading about the different types of wilwood compounds:

http://www.precisionbrakescompany.com/w ... ounds.html

Interestingly enough, precision brake is where I bought my wilwoods for my wrx 5 years ago, and they are located in Ashland Oregon as well!

Here's the same information for the carbotechs:

http://www.carbotecheurope.com/carbotec ... iction.htm

The carbotech page talks about operating temperature and coefficient of friction - both VERY important things to look at when you're choosing pads.  One of my subaru buddies has a laser heat sensor, and we've used that on our rotors after a track session, to see if we're getting out of the efficiency range of the pads.  In a 3300lb car, its not too difficult  :-\

There is also various temperature paints you can apply to rotors.   I'm talking about temperature indicating paints, that change color when they get to a certain temperature (you apply a stripe to the edge of the rotor).  Some rotors come with this applied, but its something else to play with if you're serious.

http://www.raceshopper.com/temperature_paint.shtml  

With this, you can find out what temp your rotors are getting to, and based on that make an informed decision on pads.

Bruce - agreed on your statement about the difference in the weight of the cars, no doubt about it.  All of my experience is with a 3300lb car with vacuum assist and ABS.  So the compounds that have worked for me, aren't necessarily going to be the best for the Atom.  With the lighter weight of the Atom, I'm sure you can get away with using a non-race style pad a bit longer.  Or maybe you just need to brake a little later and harder  ;)  Seriously though, the pads may be perfectly matched to the car, or the tires may be locking on you (because they are getting hot) so you think you have enough braking.  Race tires not only corner better, they brake better!  

It's impossible to tell without checking the operating temperatures of both and seeing if you're outside the range the operate at, and if their is a pad with a higher coefficient.  

Also, here is some very good general information on brakes in general.  Its a stoptech page, but the theory is applicable for any pad/rotor/caliper.

http://www.stoptech.com/tech_info/tech_ ... pers.shtml

I won't be going down to Ashland until Sept 22nd, but I'll send an email off to Craig asking about which pad is used on both the wilwoods and the Alcons, and what fluid.  I'm hoping Motul, so I can convince my wife "you can't mix fliuids, I HAVE to buy this tiny little bottle for $15!"  ;D

[Bruce Fielding]

[quote="Driver"]
Bruce if you were going that long and track days were part of it as well then you should've changed out the pads. I would've sacrificed brake pad life for one with better stopping power (better operating range)  in a heartbeat. You should've gone softer compound.  I think the answer will ultimately be a really soft compound for street driving and a more aggressive one for track use and people will just have to learn how to swap pads. It's not difficult.
[/quote]

Cheeky sod!

I wasn't aware that you were sitting beside me all the time...

I doubt that softer pads would have slowed me down that much faster to warrant the extra cost of the consumables. I don't race any more. I don't need to spend more money than Croesus on stuff I don't benefit that much from .

By all means splash all the cash you wish on getting that extra 2% out of your car (sorry, I forgot, you don't have an Atom), but since most owners barely use 75% of what their Atom can do, In my view and in my case, it's frankly not worth it.

And it IS difficult, and can be terminally dangerous if you get it wrong. Tinker with stuff that'll make your engine explode all you like, but mess amateurishly with stuff that keeps you alive at your peril, I say.

Good grief...

[Jammer]

Keep up the comments guys!
I usually run carbotechs or hawks on My Z06... and I DO drive home carefully on them... I also run either aToyo RA-1 ot Nitto R2 Extreme RR tires, which work well on street and track.  I have NO experience with NON-assisted brakes...so the tid bit above about rotor size is helpful and at minimum I am goinf with the track package at this point....we shall see if i go to the Alcons... Honestly, part of me want to have some custom 6 caliper brakes made and installed.

[07Atom]

[quote="Jammer"]
Honestly, part of me want to have some custom 6 caliper brakes made and installed.
[/quote]

I have a part of myself just like that..

[Driver]

Cheeky? Maybe. I thought this was more about getting the max from the brakes on an Atom. didn't know you had to have one to participate. Anyway it's not like I'd be amateurishly with anything. I spent almost a decade working as a mechanic. Last dealership I worked at was BMW when I got into electronics. Changing pads doesn't take a lot of knowledge to do. If you can change a flat tire or the oil in your car, then you are mechanically inclined enough to have someone show you how to do it on just about ANY car and then do it yourself from then on.

Life threatening? Not unless your in the habit of leaving bolts loose and clips out. If you are in the habit, then have a mechanic do it for you. For those people that rarely track the car, switching permanently to a pad that will get proper temps into the setup may actually be beneficial and lifesaving if they actually make road driving safer. Not talking handling, talking purely about brake performance and what it can do. If you are not getting enough heat (friction) into them then it'll make more than a 2% difference in efficiency.

07Atom and Jammer: fyi: Brembo sells a pretty nice 6 piston monoblock caliper. The ZO6 Vette uses a 6 piston setup the last few years that have 12 individual pads even.

[07Atom]

I've used a 6-piston caliper made by AP Racing before... it's another company out of Britian I think... like Alcon... though it does seem excessive for a car that weighs next to nothing.

[Driver]

It also would likely force you into running a larger diameter rim on a Atom than one would desire. But for bigger vehicles....

[Bruce Fielding]

[quote="Driver"]
Cheeky? Maybe. I thought this was more about getting the max from the brakes on an Atom. didn't know you had to have one to participate. Anyway it's not like I'd be amateurishly with anything. I spent almost a decade working as a mechanic. Last dealership I worked at was BMW when I got into electronics. Changing pads doesn't take a lot of knowledge to do. If you can change a flat tire or the oil in your car, then you are mechanically inclined enough to have someone show you how to do it on just about ANY car and then do it yourself from then on.

Life threatening? Not unless your in the habit of leaving bolts loose and clips out. If you are in the habit, then have a mechanic do it for you. For those people that rarely track the car, switching permanently to a pad that will get proper temps into the setup may actually be beneficial and lifesaving if they actually make road driving safer. Not talking handling, talking purely about brake performance and what it can do. If you are not getting enough heat (friction) into them then it'll make more than a 2% difference in efficiency.

07Atom and Jammer: fyi: Brembo sells a pretty nice 6 piston monoblock caliper. The ZO6 Vette uses a 6 piston setup the last few years that have 12 individual pads even.
[/quote]

Please don't assume that others on this forum have your spannering skills - most won't. Sorry, but in my opinion, advising people whose level of expertise you are unaware of to change brakepads in and out is utterly irresponsible.

And yes, you do have to have had experience of an Atom, or something very like it, to be able to understand the relevance of braking on a superlight car as opposed to a typical yank tank.

Ultimately, even an Atom has to be a compromise, and brakes are an area where that can happen. However, you are quite right - sometimes race brakes aren't ideal, as anyone with them will tell you, on a cold morning, the first time you press the brake pedal, bugger all happens. My old brakes were great, and all I needed on and off track.

[Myerfire48]

Im running AP 6-pots on my track prepped RX7 and am a big fan.  I love big brakes. I've also considered going with sport brakes from Brammo and then building a set of 6 pots with 12" rotors.  But like I've said in previous posts, I really dont want another car to wrench on.  I want to just get in and drive it.  So Im thinking that Brammo has probably done some homewortk here and am putting faith in the Alcons...

[benyeats]

[quote="Bruce Fielding"]

Please don't assume that others on this forum have your spannering skills - most won't. Sorry, but in my opinion, advising people whose level of expertise you are unaware of to change brakepads in and out is utterly irresponsible.

[/quote]

That is a little bit of an overeaction imo, changing pads is really as easy as Driver suggests.

If you are really mechanically clueless then perhaps try once with someone who has done it before and you will wonder what all the fuss was about.

Not sure I could be bothered to swap them before and after track days mind you

Ben

[ross]

Ditto.

Having an Atom should encourage people to become a little more 'spanner minded' IMHO.

Cheers, Ross.

[Bruce Fielding]

[quote="benyeats"]
[quote="Bruce Fielding"]

Please don't assume that others on this forum have your spannering skills - most won't. Sorry, but in my opinion, advising people whose level of expertise you are unaware of to change brakepads in and out is utterly irresponsible.

[/quote]

That is a little bit of an overeaction imo, changing pads is really as easy as Driver suggests.

If you are really mechanically clueless then perhaps try once with someone who has done it before and you will wonder what all the fuss was about.

Not sure I could be bothered to swap them before and after track days mind you

Ben
[/quote]

If anyone had seen big blokes bashing away with copper mallets on various cars as often as I have, they'd be spannershy when it comes to brakes, too!

Oh, and I am mechanically pretty clueless...

And I can't even be arsed to start reading this stuff below. However if it's useful, then please amend it for Atoms and maybe we should put it in the guides on the main site?



STEP ONE: Comfort first. Park the car in a cool, shady spot.

STEP TWO: Now safety. Block the rear wheels so the car won't roll once you jack it up. Put the car in park and set the parking brake firmly.

STEP THREE: Lay out your tools. Grab a tire iron and go to the front wheels. The tire iron is that long metal rod with a socket on the end of it that usually comes with the vehicle. You can also buy a really cool one (called a spinner) that looks like a metal cross -- in fact, it is a metal cross -- with different-sized sockets on each end.

What we want to do here, before jacking the car up off the ground, is loosen the lug nuts on the wheels just enough to break them free. So go do that. Work them off just enough until they loosen their resistance and become easy to turn with the tire iron. Now slip the jack under the car.

There are several places to safely jack up the car. If you have a floorjack, you can roll it all the way under to the center of the engine and jack it up using the K-member that holds the engine. Be careful not to use the oil pan, as you might damage it. If you have a smaller, single floor jack, you'll have to do one side at a time. Look for flat spots on the frame, immediately to the rear of the front wheels, or on the end of each axle.

CAUTION: Always use jack stands. Never attempt to work on an elevated vehicle held in place only by a hydraulic jack.

Okay, raise the front axle off the ground. Put your jack stands under each end of the axle, and lower the car onto the stands. A jack stand (see illustration) is a metal tripod with variable height adjustments. You should own two.

STEP FOUR: Remove the lug nuts and the wheel (the tire will be attached). Best to work on one wheel at a time, leaving the other side intact as a point of reference. As a safety precaution, roll the wheel/tire assembly under the front-center of the car, between the jack stands, and plop it down beneath the engine's K-member. In the event of a faulty jack stand, this will break the vehicle's fall and could possibly save your life.

STEP FIVE: Okay, take a breather. Now let's look at what we have before us.

A disc brake assembly is composed of the following elements: a caliper, two brake pads, a rotor, and some bolts and clips to hold it alltogether. It's a very simple design. Here's how it works.

The caliper comes in two flavors -- floating or fixed. Each works on a similar principle. The caliper's job is to squeeze the brake pads toward a centrally located metal plate -- the rotor -- producing friction, which in turn slows the car. Think of a hand slowly clamping down on a spinning record (or a CD, for you youngin's who've never heard the term "record" before).

The brake pads hover on either side of the metal plate. They attach to the inside of the caliper, depending on your car's design, with clips or bolts. They are composed of heat-resistant material that rubs against the rotor. When the brakes are applied, the pads move toward one another, gripping the rotor between them and slowing the wheels.

The rotor is that shiny metal disc staring you in the face right now. You can almost see your reflection, right? Get your eyes level with it. If you can't see your face, or at least its general outline, it may mean that the disc needs servicing or replacement. Below, we'll show you how to check this disc for scoring or marring, and what to do about that.

STEP SIX: Back to work. Remove the bolts holding the caliper in place. Gently slide it out and away from the rotor. Inspect the inside of the caliper. See the pads? They will be held in place by a bolt or a series of clips, sometimes both. Remove the bolts or clips holding the pads in place (remember, you left the other side intact to use as a reference) and work them free. Examine the pads. Is there any "meat" left on them, or are they worn down to the screws? If they're completely worn, you should've been hearing a metallic scrape for a while every time you applied the brakes.

Lay the pads aside and inspect the rotor. Can you see yourself in it? If the pads were worn into the metal, your rotor will be scored; you'll have trouble seeing yourself. Run your fingernails along the surface of the rotor -- careful, though; if it's been less than 20 minutes since you last drove the vehicle, they might still be hot -- first the side facing you, then the side facing away. Is it scored? Deeply? This next point is very important. If the rotor has any grooves at all in it, remove it at once. Now you have a decision to make.

If you have a scored rotor, you must decide whether to have it "turned" or to replace it. If you're short on money, take it to a local mechanic and ask him to "turn" it for you. What they do is put it on a special metal-cutting lathe and shave off several thousandths of an inch of metal until the disc is shiny again. Remember, though, one of the real advantages of disc brakes over drum is their heat-handling capability. By removing metal, you reduce the system's thermal transfer capacity. We recommend turning the discs only when you are short on bucks. The better way is to take the disc to the auto parts store, match it up with a replacement, and buy a new one. Last time we did this, it only cost us twenty bucks for a new rotor, a cheap investment in safety. You have to go there anyway to buy the new brake pads, as well as a few other things, so why not make it one trip. In fact, here's your shopping list:

    * new rotor, or rotors, if needed
    * new brake pads (bring the old ones, to match them)
    * brake pad grease (comes in little packets; they're cheap, so buy two)

STEP SEVEN: Go home and have a lemonade.

STEP EIGHT: Before you go any further, you must move the piston back to its "full open" position. The piston? you ask. Ah, we didn't tell you about that one, did we? Remember the hand-and-record analogy. As the fingers push down (equivalent to the brake pads wearing) the distance between the brake pads shortens. Now that we have brand new pads, we must return the system -- the hand -- to its original "open" position, to accommodate the new pads. There are several ways to do this.

First, find the piston. It is located along the back (closest to the engine) portion of the caliper. It's usually about three to four inches across, and resembles a small metal promontory with a flat top. See it? Depending on its condition and age, there are several things you can do to move it back (toward the center of the car). If it's new, try pushing it in with the heel of your hand. Doesn't work? Okay, then try a channel lock or a vise grip. Still won't budge? Then here's a suggestion. A neighbor of ours turned us on to this once, and it works great. Get a large C-clamp, place a thin piece of wood or cardboard over the face of the piston to protect the surface from marring, and work it back that way. As you turn the handle on the clamp, it will increase pressure on the piston, until it becomes flush with the surrounding metal. Then loosen and remove the C-clamp.

STEP NINE:Install the new rotor, if necessary. Remove the old brake pads from the caliper (usually held in place by several clips), but, before putting on the new ones, you must do something. Remember the little packets of grease you bought? These are used to lubricate the brake pads. Careful now -- not on the front of the pad, which comes in contact with the rotor, but on the back. The pads attach to the caliper via a plate-and-clip arrangement. The lubricant goes between the plate and the back of the brake pad. Got it?

Don't overlook this. If you don't do it, you'll get a horrible screeching sound every time you apply the brakes, like a dinosaur in heat (and you know how horny those velociraptors used to get). After you apply the grease, attach the pad to the plate and slide the whole thing into place.

STEP TEN:. Basically, at this point, just reassemble the system in reverse order of the way you took it apart. Now do the other side. Take the car for a test spin. Sometimes, with new brakes, you can get some weird scraping and scratching sounds; these will usually go away in a few days. Clean up, and you're done.

Don't underestimate the importance of a brake reline. As we said at the outset, absolutely nothing is more important than your car's ability to stop itself. Knowing more about your car's braking system -- getting in there and actually seeing what's going on -- empowers and informs you in a way that going to the corner mechanic doesn't.

[benyeats]

The above guide could be changed to suit the Atom and drastically simplified, the first several steps cover jacking up the car and removing the wheels, if you can't do that already then I agree changing the brake pads is too much !

Ben