DZeckhausen

Try following the bed-in procedure I have on my web site: http://www.zeckhausen.com/bedding_in_brakes.htm. It has been my experience that most people are simply not agressive enough when following the bedding procedure and if I take their car out and do it for them, the squeaking goes away. Give it a shot and see what happens.

If it doesn't work for you, there are other things to try. Often, the squealing is a high frequency fluttering of the pad in the caliper. In order to damp out those vibrations, you can apply a rubbery goo (anti-squeal compound) to the back of the pads where it comes in contact with the caliper piston in the inboard side and the caliper "fingers" on the outboard side. This damps out the vibration and stops the squeal.

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Also I notice that sometimes when I do hit the brakes they tend to pull to one side or the other. Like if I take my hand of the wheel and hit the brakes that it would pull either left or right instead of braking in a straight line. It dosen't happen every time, just some times. Are the brake calipers adjustable in anyway? The pads seem to be in contact with the rotors at all times.

This is usually caused when you apply the brakes on an uneven surface, especially where the road has some crowning from heavy trucks or lots of traffic or from frost heaves if you live up north. It's completely normal. And no, the calipers are not adjustable. I suggest you don't brake hard with your hands off the wheel!

DZeckhausen

It's possible you exceeded the MOT of your pads at the track event. Which pads did you use?

DZeckhausen

None! The Axxis Ultimate pad has an MOT of over 1,000 degrees, which is a couple hundred more than most. However, when it exceeds that MOT, it is a misbehaving pad in terms of depostion problems. In laymen's terms, this pad "poops" on your rotors and you end up with vibration and shimmy if you use it on the track.

I don't even recommend the Ultimate pads if you have the StopTech BBK and take it on the track. You might get away with it since your car is so light and (forgive me) low powered. Most of the issues come from BMW M5 owners (4100 pounds, 400 hp) who ignore me and use the Ultimate pads anyway. I strongly encourage the use of a club race type pad (e.g., Pagid Orange) for track events.

If you really, really must have a pad that you will use on the street and on the track, the Porterfield R4S may be an option. It loses friction at high tempertures and wears away rapdily, but it doesn't give you the same depostion issues as the Axxis Ultimate. If you use R-compound tires and you are an intermediate, advanced, or instructor level driver, then you may be frustrated by the pad fade you experience. But that's what you get when you use the same pad for track and street. Note: The Porterfield R4S pad should not be mistaken for the Portefield R4 pad which is a true club race pad.

DZeckhausen

Don't misinterpret me on the Axxis Ultimate, though. For anything short of a track event, it is a wonderful pad. It's just that it becomes "evil" when you take it to the track.

DZeckhausen

Similar bed-in. After doing a series of 60 - 10 mph slowdowns, you'll need to do a few from 80 mph. It's a bit harder to get the Pagid Orange pads hot enough to bed them in. Full race pads require a series of slowdowns from 100 mph.

By the way, slowing a car from 120mph to 104 mph generates the same amount of heat as stopping that car from 60 mph. The energy converted to heat goes up with the square of the velocity. So a stop from 120 mph creates four times as much heat as one from 60 mph.

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Where can I get the Pagid Orange pads and is there a certian model number or is it just "Pagid Orange"?

The Pagid Orange is called the RS 4-4 compound. I don't know if they make it for the Subaru WRX front calipers or not. I can look into it and then point you to a vendor. I don't want to cross the line here and make inappropriate posts, since I'm not a paying sponsor. I only came here to answer a few brake questions because someone emailed me and told me you guys could use a little help.

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So the Axxis Ultimate's are just a high performance street pad then right?

You've got it, by jove!

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Will it be a waste of time to do the bed-in procedure again on the Axxis pads if the exceeded the MOT? They seem to be working great still but just the squealing at low speeds.

No, you should go ahead and try again. You may be able to elimiminate the squeal entirely.

By the way, pads can unbed themselves when they are run at low temperatures exclusivly. They operate in an abrasive mode and wear away the layer of pad material from the rotor faces. If you drive like a granny for a while, your brakes may start to squeak and it's a good idea to rebed them.

Also, when switching back and forth between street and track pads, you need to go through the bedding procedure each time.

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I also noticed all the pads on your site are Axxis. Do they carry any track pads like the Pagid Orange?

No comment. I'm here as a technical resource, not a vendor. It would be inappropriate for me me to "hawk my wares" here without coughing up some cash to the administrators who run the site.

DZeckhausen

Yes, the Pagid Orange is also called the RS 4-4 compound. No, that particular compound is unique to the Pagid Orange. Nobody else uses it.

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StopTech carries a bunch of Axxis pads as well. It looks like the ones that may work are the Axxis Race Pads, Front Pads - StopTech Club Race.

Axxis makes the Deluxe, Deluxe Plus, Metal Master, and Ultimate. None of these are club race pads.

The StopTech Club Race pads are made for them by a company called Kerr Friction and have a very similar compound to the one used in the Porterfield R4 track pads.

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If you use Club Race pads on the front it would make common since to use club race pads on the rear as well, correct?

Not necessarily. The majority of the braking is done by the front brakes, especially on a dry day and even more so if you are running with sticky tires. That means that the rear rotors don't usually reach the same temperatures as the front. If you visit my write-up on the track testing day I participated in with StopTech, you can scroll to the bottom and look at the summary results in the table and compare rotor temperatures. See: http://www.zeckhausen.com/Testing_Brakes.htm With the stock brake system, the rear rotors were 250 degrees cooler than the front after a series of 100 mph stops.

Bottom line, it's very common to run with Club Race pads in the front and high performance street pads in the rear. It depends on the car, the driver, and the suspension set-up. For example, a car with a lowered suspension will have less forward weight transfer under braking and thus the rear brakes will do a larger percentage of the work than the rear brakes on a stock suspensioned car. However, you throw some sticky R-compound tires into the mix and the weight transfer forward becomes MORE pronounced and the rear brakes do LESS work. There's no single answer. You may need to experiment and see what works for you or else find someone with a similar car who is doing well at the track and ask what he/she is using.