Brake pads and rotors
- Thread starter Spaceman Spiff
- Start date
An awful lot depends on what you want to get out of your track experience coupled with the layout of the track you will be on.
I have about 17000 miles on my car with numerous track events and am still running the OEM pads/rotors with most of the pad material left and very little visible wear at all. I do keep up with a pretty fast run group, so I really don't believe the notion that the OEM brakes aren't sufficient for track use. A lot of that is dependent on the track I mostly drive - Portland Int. Raceway. We don't have mile plus long straights followed by sharp turns like some tracks I know of and those tracks will be much harder on your brake material choices than the one I drive. At the same time I am a pretty smooth driver and I tend to be what is often called a momentum driver. Another driving style I frequently encounter is to leave the throttle on the floor right up to the braking zone followed by replacing that with the brake pedal in the same position. Both driving styles will get you around the track in almost identical lap times but the latter is much harder on your car.
I did notice some brake fade the very first time I had my Z4 out on the track, but that felt like green brake pad fade and after I let the brakes cool off for a couple of laps they had a lot more bite than before and I haven't experienced any fade out on the track since. Bedding in your OEM pads prior to heading out on the track will eliminate that. The OEM brake fluid feels like it does get a bit warm and allows the brakes to feel a little soft after a day of hard use. Some stainless steel brake lines and a good high temp brake fluid like Motul or ATE might help if you are bothered that. I just make sure I bleed the brakes after track days to get the overheated fluid out and they seem like they are working just fine.
Lots of novices go out to the track with the intent to "see how fast my car is" and they gravitate towards the mash the pedal school of thought trying to see what speed they can reach in the straights. These folks will quickly wear out their brakes and tend to not learn as much about driving the car in the turns.
I try to make my students slow down earlier in the straights and be smoother entering the turns because this allows them to come out of the turn much faster than the driver who entered the turn in an unbalanced car. In the long run speed on the straights is entirely dependent on the speed coming out of the turn so the rewards of learning to drive smoothly are less wear and tear on your car while you still get to drive fast.
Bottom line - whether you really need a brake pad/rotor upgrade comes back tto how you want to drive your car out on the track and the layout of the track. If you know you are going to want to try for speed records on really long straights you might find the OEM brakes a little short of the mark. Otherwise I would simply drive the car out to the track and enjoy the experience the way BMW's engineers built it. That's been working just fine for me.
I have about 17000 miles on my car with numerous track events and am still running the OEM pads/rotors with most of the pad material left and very little visible wear at all. I do keep up with a pretty fast run group, so I really don't believe the notion that the OEM brakes aren't sufficient for track use. A lot of that is dependent on the track I mostly drive - Portland Int. Raceway. We don't have mile plus long straights followed by sharp turns like some tracks I know of and those tracks will be much harder on your brake material choices than the one I drive. At the same time I am a pretty smooth driver and I tend to be what is often called a momentum driver. Another driving style I frequently encounter is to leave the throttle on the floor right up to the braking zone followed by replacing that with the brake pedal in the same position. Both driving styles will get you around the track in almost identical lap times but the latter is much harder on your car.
I did notice some brake fade the very first time I had my Z4 out on the track, but that felt like green brake pad fade and after I let the brakes cool off for a couple of laps they had a lot more bite than before and I haven't experienced any fade out on the track since. Bedding in your OEM pads prior to heading out on the track will eliminate that. The OEM brake fluid feels like it does get a bit warm and allows the brakes to feel a little soft after a day of hard use. Some stainless steel brake lines and a good high temp brake fluid like Motul or ATE might help if you are bothered that. I just make sure I bleed the brakes after track days to get the overheated fluid out and they seem like they are working just fine.
Lots of novices go out to the track with the intent to "see how fast my car is" and they gravitate towards the mash the pedal school of thought trying to see what speed they can reach in the straights. These folks will quickly wear out their brakes and tend to not learn as much about driving the car in the turns.
I try to make my students slow down earlier in the straights and be smoother entering the turns because this allows them to come out of the turn much faster than the driver who entered the turn in an unbalanced car. In the long run speed on the straights is entirely dependent on the speed coming out of the turn so the rewards of learning to drive smoothly are less wear and tear on your car while you still get to drive fast.
Bottom line - whether you really need a brake pad/rotor upgrade comes back tto how you want to drive your car out on the track and the layout of the track. If you know you are going to want to try for speed records on really long straights you might find the OEM brakes a little short of the mark. Otherwise I would simply drive the car out to the track and enjoy the experience the way BMW's engineers built it. That's been working just fine for me.
20ducks said:
I thought you only needed to replace the sensors if they actually touched the rotors from excessive pad wear...
A little report of my first track expérience !
I had a lot of fun, really. In this regard, the aim of the day is perfectly achieved.
I was a bit nervous at first, not knowing about how my car would react and how I would react as well, in high-speed-sharp-corners and all, but everything went smooth. I'm really glad i took the instructor lesson option, that was really helpful.
I just have one little remark : braking !
OK, the OEM braking fitment of the Z4 is fine, brakes hard and all, but it doesn't last very long. So i want something better. not something which brakes harder, but something which last longer. After 15 minutes of track, the brake pedal was getting a bit soft. And after two sessions, it was reaaaaally soooooft.... i was even a bit frigthened by that (when returning to the parking space, i almost could'nt stop the car at 10 km/h...).
So, what can i do, simply, to upgrade my brakes ?
I was thinking of steel lines and a better brake fluid, at least for a start. Will this have the effect i want ?
I had a lot of fun, really. In this regard, the aim of the day is perfectly achieved.
I was a bit nervous at first, not knowing about how my car would react and how I would react as well, in high-speed-sharp-corners and all, but everything went smooth. I'm really glad i took the instructor lesson option, that was really helpful.
I just have one little remark : braking !
OK, the OEM braking fitment of the Z4 is fine, brakes hard and all, but it doesn't last very long. So i want something better. not something which brakes harder, but something which last longer. After 15 minutes of track, the brake pedal was getting a bit soft. And after two sessions, it was reaaaaally soooooft.... i was even a bit frigthened by that (when returning to the parking space, i almost could'nt stop the car at 10 km/h...).
So, what can i do, simply, to upgrade my brakes ?
I was thinking of steel lines and a better brake fluid, at least for a start. Will this have the effect i want ?
Shooter said:
That is an excellent start point. A soft pedal is an almost certain indication that your brakes are getting hot enough to boil the fluid in the lines. Steel lines will also help a little but a good high temp fluid is the best (and cheapest) place to start.
If your pads had gotten cooked the results would have been far more dramatic because you would have had zero brakes when you were looking for them in the braking zone out on the track. Once you have felt that one there will be little room for doubt about the fact that you want new pads but your description sounds more like overheated brake fluid. Bleed the lines out (I do after every track day anyway) to flush out the stuff at the ends and you should be fine until the next track day. Motul RBF 600 has always been a nice solution for my cars through the years when lots of track time is involved.
Me again ! 
Are there any drawbacks wth the motul RBF 600 ?
Is it a "true" DOT4 fluid, just better, or is it a "false" DOT5.1 which does meet certain requirements to be a DOT5.1 ?
In other word : can i keep the RBF600 fluid in my car as my "every day" fluid for the next two years ?
Are there any drawbacks wth the motul RBF 600 ?
Is it a "true" DOT4 fluid, just better, or is it a "false" DOT5.1 which does meet certain requirements to be a DOT5.1 ?
In other word : can i keep the RBF600 fluid in my car as my "every day" fluid for the next two years ?
I have used RBF600 in my last 3 cars (2004 Audi B6 S4, 2005 Honda S2000, and 2007 Z4 Coupe) year round with no problems.
I do flush the brakes after every event (typically 3/4 of a bottle) so I would be hard pressed to state that I left the same fluid in for 2 years.
I do flush the brakes after every event (typically 3/4 of a bottle) so I would be hard pressed to state that I left the same fluid in for 2 years.
Back from the track !
The RBF600 did its job perfectly : the pedal stayed firm throughout the day, i didn't experienced the same feeling than my first track session.
But... i think i just killed my pads...
At the end of the day, braking was OK for the first 3 laps, then braking distance increased dramatically. I had to stop after 5 laps because i was getting very uncomfortable.
So, considering i will most probably not go to another track session before long, i will change the pads for something more "gentle" to my rims (namely, i will probably go for Axxis Advanced brake pads).
Another question : how do i know i need to change my discs as well ?
The RBF600 did its job perfectly : the pedal stayed firm throughout the day, i didn't experienced the same feeling than my first track session.
But... i think i just killed my pads...
At the end of the day, braking was OK for the first 3 laps, then braking distance increased dramatically. I had to stop after 5 laps because i was getting very uncomfortable.
So, considering i will most probably not go to another track session before long, i will change the pads for something more "gentle" to my rims (namely, i will probably go for Axxis Advanced brake pads).
Another question : how do i know i need to change my discs as well ?
I'm going to bump this up and ask my questions here.
A little back history first,
I found out that once my confidence in the car and knowledge of the track went up I started driving 8-9/10ths on the track, at least for my skill level. So at any rate approx 25 minutes into a 30 minute run session I got brake fade real bad. I'm pretty sure I boiled the fluid as the soft pedal was still there for the next run session approx 40 minutes later. There were lots of brake use slowing from approx 90mph to about 40mph.
I'm currently running axis deluxe pads with ATE TYP 200 Brake Fluid.
I'm thinking that no matter what I'll switch to the RBF600 for track days.
I'll most likely switch pads out too as now i'm paranoid of these pads for track use
So my questions are this:
1) Should I upgrade only one part of the system for my next track event (pads or brake fluid)
2) What set of pads should I get? Should I go with an actual set of race pads or would the Axis deluxe ULT be good enough?
3) What track pads would ya'll recommend?
Oh one more
4) Should I get an extra set of rotors to avoid extra bed in procedures?
A little back history first,
I found out that once my confidence in the car and knowledge of the track went up I started driving 8-9/10ths on the track, at least for my skill level. So at any rate approx 25 minutes into a 30 minute run session I got brake fade real bad. I'm pretty sure I boiled the fluid as the soft pedal was still there for the next run session approx 40 minutes later. There were lots of brake use slowing from approx 90mph to about 40mph.
I'm currently running axis deluxe pads with ATE TYP 200 Brake Fluid.
I'm thinking that no matter what I'll switch to the RBF600 for track days.
I'll most likely switch pads out too as now i'm paranoid of these pads for track use
So my questions are this:
1) Should I upgrade only one part of the system for my next track event (pads or brake fluid)
2) What set of pads should I get? Should I go with an actual set of race pads or would the Axis deluxe ULT be good enough?
3) What track pads would ya'll recommend?
Oh one more
4) Should I get an extra set of rotors to avoid extra bed in procedures?
Interesting thread guys!
I'm also planning on my first upgrade to the Z4, and plan to be using it quite a bit on the track come spring, so I'm going with the following modification;
-StopTech's SportStop drilled rotors/discs,
-StopTech stainless steel brake lines,
-Axxis Ultimate street performance pads
-3 bottles of Motul RBF600 brake fluid.
Ive found this to be available for both front/back for about £750GBP in the UK, seems like an OK price to me?
My personal experience seems to certainly mirror a lot of others - i.e. once the brake fluid has heated up, the soft pedal really results in loss of confidence - and I just want to be able to rely on it for a lot longer. Other than that, for short periods of time, the brakes are very impressive.. So step one, upgrade as above, and then maybe start looking at some new callipers
Krzys
I'm also planning on my first upgrade to the Z4, and plan to be using it quite a bit on the track come spring, so I'm going with the following modification;
-StopTech's SportStop drilled rotors/discs,
-StopTech stainless steel brake lines,
-Axxis Ultimate street performance pads
-3 bottles of Motul RBF600 brake fluid.
Ive found this to be available for both front/back for about £750GBP in the UK, seems like an OK price to me?
My personal experience seems to certainly mirror a lot of others - i.e. once the brake fluid has heated up, the soft pedal really results in loss of confidence - and I just want to be able to rely on it for a lot longer. Other than that, for short periods of time, the brakes are very impressive.. So step one, upgrade as above, and then maybe start looking at some new callipers
Krzys