What brake pads to use?
Discussion
I recently installed EBC reds for a track day. During the first few laps under hard braking the brakes would shudder real bad, violently shaking the stearing wheel. After what I asume are the pads warming up, the shuddering goes away. The last lap the brakes just plain old worked like CRAP. Lots of brake fade.
I still have the EBC reds on for the street. They work fine. No shuddering because I'm not braking from 140. But they do seem to be grabbing. Warped rotors?? Don't know. I can't get the damm things off because I stripped the bolt/screws that holds the rotors on.
Any suggestions on good street/trackday pads. Willing to switch pads before track days. For a 99' with Brembos
Thanks, Eric GREAT FORUM!!
I still have the EBC reds on for the street. They work fine. No shuddering because I'm not braking from 140. But they do seem to be grabbing. Warped rotors?? Don't know. I can't get the damm things off because I stripped the bolt/screws that holds the rotors on.
Any suggestions on good street/trackday pads. Willing to switch pads before track days. For a 99' with Brembos
Thanks, Eric GREAT FORUM!!
Hi,
The brake shudder that you experienced was probably due to an incomplete transfer layer on your rotors from the new pads. When changing out pads (of different compounds) you really are supposed to either change rotors or have your rotors turned to remove all of the old pad compound transfer layer. The layer is applied during a proper pad bedding procedure and an old layer of different compound will cause an inconsistent layer to be applied which can cause different levels of friction over the operational circumference of the rotor. This would have the effect of juddering brakes and the steering wheel jumping out of your hands. Uneven distribution of pad transfer layer can also lead to hot spots on the rotor that can ruin them.
The fact that you experienced brake fade towards the end was probably because EBC reds aren't the greatest pad in the world and were just plain overheated.
During street use the problems of pad transfer layer are not always apparent since the brakes usually have to be up to full operating temp for the symptoms to occur.
My advice to you is to figure out how you plan on using the car. There is no rotor/pad combo that is perfect for the street as well as for a spirited track day. If you track your car a lot as I do I would suggest running a race pad with a high level of friction at cold temps, this way they are still usable on the street. If you drive on the street 95% of the time you either have to get yourself a dedicated set of pads and rotors for the track or deal with the short comings of swapping pads onto improperly prepared rotors.
P.S. I hear Porterfield R4's aren't bad.
Mike R.
94'S4 NY/NJ LEO
The brake shudder that you experienced was probably due to an incomplete transfer layer on your rotors from the new pads. When changing out pads (of different compounds) you really are supposed to either change rotors or have your rotors turned to remove all of the old pad compound transfer layer. The layer is applied during a proper pad bedding procedure and an old layer of different compound will cause an inconsistent layer to be applied which can cause different levels of friction over the operational circumference of the rotor. This would have the effect of juddering brakes and the steering wheel jumping out of your hands. Uneven distribution of pad transfer layer can also lead to hot spots on the rotor that can ruin them.
The fact that you experienced brake fade towards the end was probably because EBC reds aren't the greatest pad in the world and were just plain overheated.
During street use the problems of pad transfer layer are not always apparent since the brakes usually have to be up to full operating temp for the symptoms to occur.
My advice to you is to figure out how you plan on using the car. There is no rotor/pad combo that is perfect for the street as well as for a spirited track day. If you track your car a lot as I do I would suggest running a race pad with a high level of friction at cold temps, this way they are still usable on the street. If you drive on the street 95% of the time you either have to get yourself a dedicated set of pads and rotors for the track or deal with the short comings of swapping pads onto improperly prepared rotors.
P.S. I hear Porterfield R4's aren't bad.
Mike R.
94'S4 NY/NJ LEO
Eric:
Try the CarboTech (www.CarboTechEng.com) Panther Plus for the track or the Bobcat for the street. If you are like me(lazy some days), use the Panther Plus on the street too. Little squeaky but work well.
Talk to Matt Nicholson at CarboTech.
Feff
Try the CarboTech (www.CarboTechEng.com) Panther Plus for the track or the Bobcat for the street. If you are like me(lazy some days), use the Panther Plus on the street too. Little squeaky but work well.
Talk to Matt Nicholson at CarboTech.
Feff
I went through this exercise last year. Mike is 100% spot on. You probably got bad transfer to the rotors. Read the article from Carroll Smith on "warped rotors" -- rarely if ever happens. What happens is you get uneven transfer of pad material when you first put the new pads on and the juddering is those imperfections that result in the rotor. You can "clean" them off with a turning of the disc, but it is temporary.
In addition to Mike's comments, what you really need to do is bed in the brakes properly. Most pads come with bed in instructions, but the gist of it is several increasingly harder stops from 60-80 mph followed by a cool off period. This is THE most crucial step in getting a new set of pads and rotors to work and to avoid the issues you had.
Second, Mike is right in that you never want to use new pads and rotors at teh same time. Turn the old rotors and use them to bed in the pads, then put new rotors on and use the scruffed pads to bed in the rotors.
Last, I tried EBC greens. Terrible pads. Avoid them. Went to Porterfield R4s (I track 2-3 times a year, drive on the street 2-3 times a week). I like them.
Carbotech is a great bunch, local to me (Charlotte NC, I'm in Raleigh). The last time I called they did not have pads made up for a pre-Brembo SE/S4 and they wanted me to send in the backing plates for a model. They do have premade V8 pads, and Brembo S4s pads made up. Panthers and Bobcats are decent street pads. Talk to them about their Hawk equivalents (XP-9 and 10 I think) if you track the car a lot.
>> Edited by JeffYoung on Tuesday 13th December 15:25
In addition to Mike's comments, what you really need to do is bed in the brakes properly. Most pads come with bed in instructions, but the gist of it is several increasingly harder stops from 60-80 mph followed by a cool off period. This is THE most crucial step in getting a new set of pads and rotors to work and to avoid the issues you had.
Second, Mike is right in that you never want to use new pads and rotors at teh same time. Turn the old rotors and use them to bed in the pads, then put new rotors on and use the scruffed pads to bed in the rotors.
Last, I tried EBC greens. Terrible pads. Avoid them. Went to Porterfield R4s (I track 2-3 times a year, drive on the street 2-3 times a week). I like them.
Carbotech is a great bunch, local to me (Charlotte NC, I'm in Raleigh). The last time I called they did not have pads made up for a pre-Brembo SE/S4 and they wanted me to send in the backing plates for a model. They do have premade V8 pads, and Brembo S4s pads made up. Panthers and Bobcats are decent street pads. Talk to them about their Hawk equivalents (XP-9 and 10 I think) if you track the car a lot.
>> Edited by JeffYoung on Tuesday 13th December 15:25
Thanks everyone,
I will try the Carbotechs.
Just so I don't sound like a complete idiot. I did follow the break in procedures that came with the EBC reds. Sounds similar to what you said. I think my main prob was that I didn't get the old rotors turned. I did use brake cleaner, and the rotors were in great shape.
Thanks
I will try the Carbotechs.
Just so I don't sound like a complete idiot. I did follow the break in procedures that came with the EBC reds. Sounds similar to what you said. I think my main prob was that I didn't get the old rotors turned. I did use brake cleaner, and the rotors were in great shape.
Thanks
Porterfields r4s are fine for the street but are useless on a track - you will wear them out very quickly.
I've used pagid rs14 which were great for hard /track use if a little noisy.
If you are going to do a lot of track work the AP set up is much MUCH better than the brembo. I updated my 98 from brembos to AP - huge difference IMO.
Have also used Ferodo DS2500 with the AP calipers which were great.
I've used pagid rs14 which were great for hard /track use if a little noisy.
If you are going to do a lot of track work the AP set up is much MUCH better than the brembo. I updated my 98 from brembos to AP - huge difference IMO.
Have also used Ferodo DS2500 with the AP calipers which were great.
JeffYoung said:
Rob, I've had decent experience with the R4s on track -- get 2-3 track weekends out of them, but then again VIR is not too terribly hard on brakes. How much wear do you usually get?
dermot had porterfields in for vmax. about 10 stops from 165 mph and they were toast ie back to the backing plate. rob c had a set (brand new) in his 350 for a track day at goodwood a few years back. he had no material left after only a few hours on track.. had to drive back very carefully..
for the above reasons, i'd already removed my porterfields before i did any track stuff
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