e39 M5 brake discs/calipers

[moochofun]

nonuts said:

Define 'upgrade' is the problem most people have. If the only issue is brake fade then you don't need to upgrade the calipers or discs, just the pads and fluid. Also for a number of kits the brake discs are actually a downgrade from the M5 EU OEM discs in terms of size or thickness so it depends on the kit and whether the only benefit is pad area on the disc and whether that's necessary. There are also issues if you just upgrade the front that you may screw up brake balance. After reading all of the potential issues I went with OEM discs, RS29 pads, upgraded fluid and stainless hoses all round and don't regret it at all. Haven't had fade or brake issues once since.

Hmmmm....guess my definition of upgrade (in respect to my M5 brakes) is that I wanted better... Agree entirely with what you are saying - like everything else, there is many ways to skin the cat, how you get there then its each to his own... This thread seemed to be going for OE discs and OE pads, hence my comment about the thinking on staying standard - I'm not implying the way I did it is the only or best way, it was the way I wanted to do it

[Patrick Bateman]

I don't see what the big deal is. For road use, I'd argue if the brakes are letting you down you're driving way too hard for the road personally.

The occasional track venture I could understand but even then the ring taxi only had upgraded pads and fluid. Factor in cost with the fact that I've never had an issue in the first place and it'd be a massive waste of money.

[Patrick Bateman]

Rears up next shortly. The discs are an absolute mess, even in comparison to those old fronts.

[Tom W]

What a vast improvement. Those old discs were certainly looking past their prime. How do they feel, now they are on the car and how are the standard pads?

[Patrick Bateman]

I've always been happy with standard pads. Still need a few more miles of bedding them in but the initial bite is already much sharper and the pedal isn't so soft.

[Patrick Bateman]

Got the rear discs now from that Ocean BMW shop on ebay and they aren't coated like the front ATE ones. I'm curious to see the comparison regarding resistance to corrosion around the circumference between the two types.

Not sure who supplies BMW for the rear discs as ATE only list the fronts in their own parts catalogue.

[Depthhoar]

Pretty sure that if you follow the usual bedding in procedure (10 sequential hard stops from 60mph down to 5mph) then that cosmetic coating will be gone and look very little different to equivalent non-coated BMW OE version that's had similar treatment.

I guess coating rotors is a point of sale thing which some manufacturers have adopted to make their product stand out. From a practical point of view, it's utility is distinctly questionable given the amount of heat & friction involved.

[Patrick Bateman]

I meant on the outer edges of the disc that are untouched.

[Depthhoar]

Ah, yes. Take your point.

A mighty amount of heat will still be transferred the few millimetres to the outside edge. Be interesting to see how long the coating lasts there.