A quick Alcon brake review (glass half full for Dan) ;-)

[titan]

Righto, first trackday in the CSL...Snetterton. I've done Snet around 4 times in the past so it should make for a reasonable assessment on the car rather than trying to learn lines etc etc

Initial assessment is that they have all the stopping power you need, certainly (it was dry) I was seeing some ABS action on hard braking (conti sport tyres). I think a quote from someone else sums it up "King of the Late Brakers"

However longevity, feel and noise/vibration is an issue. After a few laps I was getting slight wobble in the wheel, moreso under braking, the pedal didn't feel as rock solid and braking produced that droning, rumbling noise.

Quick inspection of the discs and they show a "smearing" in sections and the surface is lined rather than a smooth finish.

Driving the car home and its pretty bad now. Now I'm no brake guru, so I'm open to suggestions here, but this seems to be exactly what happened on my brothers R26R when we used an incorrect pad compound. The pad can't deal with the heat and starts to break down, putting deposits onto the disc and generally its all a bit crap.

I am using RS29's. One suggestion offered up was to try RS19s.

As I say, I've experienced this before and to a lesser degree on the evo using carbotech pads - the fix was to simply move up a compound.

I think I'll have a go at cleaning up the discs (unlikely that they are warped) and switch over to carbotech XP10s - this being what I run on the evo which is a similar weight car. I have zero issues with longevity using these pads and I think they'll work just fine. I believe the pads are the exact same on the evo so it would be nice to only keep stock of one pad for both cars.

UBs assessment of the brakes were that they are "monsters" certainly I have been surprised at how much the rear brakes seem to bring to the party. From what I've seen my generalisation is that people who choose AP tend to do only the fronts whereas people choosing Alcon do the whole kit. Not sure why this is, Alcon do recommend doing front and rear as a matched set to not upset bias, I'm sure AP recommend the same as well.

Anyhow a good day and made a lot better by turning off the DSC entirely - I was under the impression that "track mode" was lots less intrusive, my reality was that it cut in far too much and got in the way. I note that on Gareths car with his R888 he didn't get much telltale light on the dash so no surprises big rubber also helps.

[shimmy]

RS29 are superb so not the cause so dont bother replacing them. They are hard as can be and you certainly dont want harder metal based pads and all that entails.

giove them a clean and see what happens.

Most likely cause is that you have not bedded them in properly (assuming they were fitted new). Did you do the full sickeningh bedding in process?

Originally Posted by titan

Righto, first trackday in the CSL...Snetterton. I've done Snet around 4 times in the past so it should make for a reasonable assessment on the car rather than trying to learn lines etc etc

Initial assessment is that they have all the stopping power you need, certainly (it was dry) I was seeing some ABS action on hard braking (conti sport tyres). I think a quote from someone else sums it up "King of the Late Brakers"

However longevity, feel and noise/vibration is an issue. After a few laps I was getting slight wobble in the wheel, moreso under braking, the pedal didn't feel as rock solid and braking produced that droning, rumbling noise.

Quick inspection of the discs and they show a "smearing" in sections and the surface is lined rather than a smooth finish.

Driving the car home and its pretty bad now. Now I'm no brake guru, so I'm open to suggestions here, but this seems to be exactly what happened on my brothers R26R when we used an incorrect pad compound. The pad can't deal with the heat and starts to break down, putting deposits onto the disc and generally its all a bit crap.

I am using RS29's. One suggestion offered up was to try RS19s.

As I say, I've experienced this before and to a lesser degree on the evo using carbotech pads - the fix was to simply move up a compound.

I think I'll have a go at cleaning up the discs (unlikely that they are warped) and switch over to carbotech XP10s - this being what I run on the evo which is a similar weight car. I have zero issues with longevity using these pads and I think they'll work just fine. I believe the pads are the exact same on the evo so it would be nice to only keep stock of one pad for both cars.

UBs assessment of the brakes were that they are "monsters" certainly I have been surprised at how much the rear brakes seem to bring to the party. From what I've seen my generalisation is that people who choose AP tend to do only the fronts whereas people choosing Alcon do the whole kit. Not sure why this is, Alcon do recommend doing front and rear as a matched set to not upset bias, I'm sure AP recommend the same as well.

Anyhow a good day and made a lot better by turning off the DSC entirely - I was under the impression that "track mode" was lots less intrusive, my reality was that it cut in far too much and got in the way. I note that on Gareths car with his R888 he didn't get much telltale light on the dash so no surprises big rubber also helps.

[_Nathan_]

RS29 are fine for longetivity, used in 24H races for a start, no issues with them on mine (Aps all round if that makes any difference).

Quote from Pagid on the RS29
"Yellow Direct development of RS19, with improved initial bite and offering more temperature stable operation at higher temperatures"

Not sure that 19 will offer you anything more?

[Dan]

Cheers Lee, glad you had a good day and gave a decent review on them!

[shane@mbtech]

I rate the Alcons no better than the AP's to be honest.
They look the part, but offer no better braking. #
Ive ran, K sports, ap, alcon, standard all on my CSL.

[NZ_M3]

I had the exact same issues when I started with my Alcons - tried various pad options, STS from Alcon, Ferod DS2500, DS3000 RS2.1, and now Pagid RS29 - it's a bedding in issue and a heat retention issue with the Alcons - especially on a CSL and the lack of cooling vents for brakes.

The DS3000 are boarderline but will start to grumble and rumble and eventually cause juddering after very hard braking, the RS2.1s I've not yet tried, and the Pagid RS29s are brilliant but needs to be bedded in properly.

If you are seeing smearing in sections then the pads are breaking down unevenly.

Another possibility is the mounting - if the caliper isn't mounted parallel to the disc it'll cause this - very easy to do with the Alcons when changing pads as you basically have to disassemble the caliper from the mounting brackets - very easy to put them on slightly offset - measure it.

Check back on an old thread I put up on the exact same issues.

[glendog74]

Isn't it somewhat ironic that you are now getting issues with your Alcons - especially as you pretty much rubbished APs in another thread :

Originally Posted by titan

Past that its all about brakes and suspension on track cars. Don't go wasting money on APs which get so many duff customer feedbacks (rattling, warped/cracked discs) as well as good, so straight for the Alcon kit which *only* gets great reviews. 365 up front (bigger than AP) and 348 rears I think. Either buy from an Alcon place, or get the CSL Cup kit from Thorney, its the same thing.

This certainly isn't the first time that i have read of problem issues with the Alcon kit - there was a thread on this very site some time ago and i have also seen stuff written elsewhere. I think people seem to get blinded by the whole 'Alcon has bigger/monobloc callipers and costs more than AP so must be better' syndrome...

I am on my second full set of AP discs and fourth set of RS29s and have never had issues in 2 years of track abuse. My first set of front discs did have one of the dreaded AP cracks on the inside face of one disc but this was only evident after almost 15k miles. And ok, i do have some of the annoying squeaking and 'thunks' from the RS29 pads - but that is a minor issue to me as i don't use it as a daily driver anymore and certainly don't feel the need to pose around town in my CSL!

At the end of the day all BBKs and any other brake kit for that matter can have the issues that you and others have experienced, especially if not bedded in correctly.

Just my 2p worth...

[glendog74]

Originally Posted by titan

From what I've seen my generalisation is that people who choose AP tend to do only the fronts whereas people choosing Alcon do the whole kit. Not sure why this is, Alcon do recommend doing front and rear as a matched set to not upset bias, I'm sure AP recommend the same as well.

You'll find many people who upgrade only the fronts to AP brakes do so with road use in mind as they don't always intend to track the car. AP fronts are somewhat cheaper than Alcons and have been around a lot longer in the M3 CSL lifespan whereas Alcons are relatively new on the scene with respect to the M3 CSL iirc. A no brainer for someone who purely wants reliable braking would be to go AP and many of these kits would have been fitted some years ago.

Originally Posted by titan

Anyhow a good day and made a lot better by turning off the DSC entirely - I was under the impression that "track mode" was lots less intrusive, my reality was that it cut in far too much and got in the way. I note that on Gareths car with his R888 he didn't get much telltale light on the dash so no surprises big rubber also helps.

'M Track' mode is a lot less intrusive on track - especially if you are a smooth driver. I very rarely get the DSC light up when driving on track. If it does it is usually due to wet/damp patches on track or when the car goes light - on certain points of the Nurburgring for example, Flugplatz, Pflanzgarten, etc.

If you drive the car aggressively or are not smooth then the DSC will cut in - simples!

[shimmy]

I've had at APs for 50k miles and 50 trackdays. More than adequate and the better driver you become the less trouble you get from them.

Swapping out the pads and discs is the easiest job in the world BUT OCCASSIONALLY you get depositsxand rumbling. Key id to bed in very hard and fully after fitting. My callipers have been faultless, I had all pistons seals replaced as preventative repair this year.

I can categorically say that on E46 there can be no other reason for fitting another make other than cost.

[DazBlackCSL]

+1