[parapaul]

Originally Posted by m1bjr

I also went the EBC slot and dimpled discs all round route. Only as mine were shot after tracking it.

Just out of interest, how do you find these discs in terms of noise? I had a set of grooved discs on a previous car and the constant humming became a real PITA, really quickly. I've wondered whether the dimples or their wierd crescent shaped slots would help cut down the noise.

[F31-340i]

Found my thread which maybe of use, not sure if links still work....

http://www.e90post.com/forums/showthread.php?t=375886

[Kerr]

Have a look here. These are the same ones being sold on ebay. http://www.google.co.uk/url?sa=t&sou...3lG79IrkPq9vkQ

The brand of discs is MTEC.

I read through a few sites and the opinions seem to be good, especially for the money.

One guy had issues with the black discs where the coating had not cured and it ruined his redstuff pads.

MTEC replaced the discs and also refunded the costs of the redstuff pads and the guys garage costs too.

The 335i brakes come under E93(they are the same are they not?) and come in at £212 for a full set of discs and pads with free delivery.

[markymark34]

Originally Posted by MEGA

I've never heard of this before.. Then again I'm not particularly long in the tooth or mechanically savvy.

Is there a site or resource that explains the benefits and procedure of having this done?

It seems to me like it would just wear down the disk and cause you to need it replacing sooner which is not a good thing.. But you know your stuff so I'm sure it's worthwhile.

I usually just bed them in with 10x 40-0mph stops followed by 10x 70-0mph stops or similar?

Ive never been a big fan of wearing the brakes in at all! My mechanic that also works as a mechanic for a rally team always tells me just to go mega gently for the first 100 ish miles and it will give me much longer out of a set of pads rather than any of the wear in methods which he says are really for cars being raced. So far ive had about 5 or 6 brake pad changes (over 17 years) and never had any issues at all.

Similar to you though i dont know anything about the +s or -s of all this mechanical stuff.

I bought front pads from BMW and they were £100 so looks like decent savings to be had.

[m1bjr]

Nothing to do with bedding in pads gents.
All to do with a very large spinny disk that has a manufacturing tolerance.
And hubs that may not be totally true.
The two together give a cumulative error, a tiny 'wobble' actually.
Its barely noticable when new, but a few K miles later the disc thickness wears unevenly.
Exactly why so many people complain of 'warped' discs every 6m

Not every car/disc combination will suffer, but the EBCs tolernace was not so tight from the factory.
Add to the fact that my hubs are not perfect (most are not) and it juddered a lot at speed.

[m1bjr]

Originally Posted by parapaul

Just out of interest, how do you find these discs in terms of noise? I had a set of grooved discs on a previous car and the constant humming became a real PITA, really quickly. I've wondered whether the dimples or their wierd crescent shaped slots would help cut down the noise.

Hey Paul,
Yes they do make a noise. I dont like it much but its only noticable windows down driving past walls

Kind of a light ticking sound, my guess is the air through the grooves chattering the pads.
As I know my rotors are perfectly true

Under braking they make a quiet whooshing sound, only audible with windows open too.

Cold they stop a bit better than oem.
Hit them hard a couple of times to heat them and they are 50% bette than oem.
Very powerful and I havent had them fade yet

[3erdriver]

Originally Posted by m1bjr

I also went the EBC slot and dimpled discs all round route. Only as mine were shot after tracking it.
OEM are overpriced and I couldnt justify 4k on 2pc Brembos etc.
With redstuff first (no better than oem) now Yellowstuff - much better at high temps.

Better than new

ok, so i've been reading up on pads and rotors. i thought i'd do redstuff and either zimmerman blanks or ebc blanks. no tracking but i do appreciate good braking. you feel yellow is much better? how's the dust compared to red? that seemed like a nice bonus compared to the oem!

[Kerr]

Originally Posted by m1bjr

Nothing to do with bedding in pads gents.
All to do with a very large spinny disk that has a manufacturing tolerance.
And hubs that may not be totally true.
The two together give a cumulative error, a tiny 'wobble' actually.
Its barely noticable when new, but a few K miles later the disc thickness wears unevenly.
Exactly why so many people complain of 'warped' discs every 6m

Not every car/disc combination will suffer, but the EBCs tolernace was not so tight from the factory.
Add to the fact that my hubs are not perfect (most are not) and it juddered a lot at speed.

I'd genuinely hope that all machined surfaces are held to within just a few thou.

The nature of cast iron is you are not likely to have anywhere near an exact metal consistency and have various hot spots through the metal. This will cause discs to wear slightly uneven.

Also cast iron does distort under high temperatures.

How often are you having your discs skimmed?

Do they just skim both faces or skim the outer diameter too?

[m1bjr]

Originally Posted by jimH6

ok, so i've been reading up on pads and rotors. i thought i'd do redstuff and either zimmerman blanks or ebc blanks. no tracking but i do appreciate good braking. you feel yellow is much better? how's the dust compared to red? that seemed like a nice bonus compared to the oem!

Less dust than red or oem.
Less aggresive on the metalwork too.
My top choice would always be Carbotech.
But cant justify it on what is this year going to be a 99% roadgoing car tbh.

[m1bjr]

Originally Posted by Kerr

I'd genuinely hope that all machined surfaces are held to within just a few thou.

The nature of cast iron is you are not likely to have anywhere near an exact metal consistency and have various hot spots through the metal. This will cause discs to wear slightly uneven.

Also cast iron does distort under high temperatures.

How often are you having your discs skimmed?

Do they just skim both faces or skim the outer diameter too?

Check out the BMW allowable runouts, you may be surprised.
And EBC iirc quote <0.05mm.
Thats very low.

I only did this on-car machining once, now I am a convert.
The tooling has a gyro and everything to allow for every circumstance.
Its very common practice in a lot of EU, we are just doggedly ignorant