E34 M5 Nurburgring rotors and calipers - United Bimmer Community

**dinan540** · 03-07-2006, 10:17 PM

Anyone know if these would install on a 540i? Just curious.

**euro driver e34** · 05-01-2006, 04:02 AM

Depends, compare the spacing of the diameter on the hub ifnot find the whole assembly it should match up with the linkage. Or you can just upgrade to a ceramic big brake kit depending on what you are trying to do.

Storamin · 05-01-2006, 07:27 AM

no idea, but i'm guessing that e39 m5 rotors/calipers would fit.

**dinan540** · 05-01-2006, 02:35 PM

I just picked up some e39 m5 rotors and calipers. The rotors are 20 mm wider and the calipers are bigger, but both are still single piston.

Storamin · 05-01-2006, 02:56 PM

there's nothing that says multi piston is neccesarily better...

**dinan540** · 05-01-2006, 05:57 PM

Storamin,

I always thought that multi-piston would be better. Is there a similar argument about vented and non-vented rotors? I would assume that the bigger piston would help with braking.

Storamin · 05-01-2006, 06:14 PM

theoretically, yes, more pistons will help with braking. multi-piston caliper works more efficiently and transfers a larger area of friction to the rotor because pressure is exerted equally on both sides of the rotor by a series of individual pistons working together. There's a lot of science and engineering required to formulate the most efficient ratios between the fluid moved by your master cylinder to the number and size of pistons in the brake caliper. Virtually dozens of companies sell multi piston disc brake calipers for performance applications. Some work great and some do not work any better than the stock calipers.

don't get me started on the crossdrilled rotors...
Cracking is limited mostly to drilled discs, which get small cracks around outside edges of the drilled holes near the edge of the disc due to the rotor's uneven rate of expansion in severe duty environments. Manufacturers that use drilled rotors as OEM are doing so for two reasons: looks if they determine that the average owner of the vehicle model will not overly stress them; or as a function of reducing the unsprung weight of the brake assembly, with the engineering assumed that enough brake rotor mass remains to absorb racing temperatures and stresses. A brake disc is a heat sink, so removing mass increases the heat stress it will have to contend with.

how much are the e34 m5 nurburgring rotors/calipers versus e39 m5? i think the e39 m5 setup with a nice set of pads will do wonders.

**cainchapman** · 05-02-2006, 03:01 AM

Unnecessary expenditure in my opinion. My car has Mintex 1166 pads, excellent tyres (do more for braking than bigger discs under normal conditions). I have fitted Brembo slotted rears (to no significant performance increase) that are the standard size 300mm. OEM 302mm from rotors.

As tested by NZ Autocar 100kph-0 (62mph-0) in 30.92m (101feet). This was the 3rd fastest stopping ever tested by them at that time. Faster than a V10 M5, Ferrari F430 etc.

And at not a lot more than fitting standard components.

If you got them cheap and know someone that can fit the M5 gear, then you will get a better braking package. Pads & tyres are where bigger gains can be made.

**jybute** · 05-02-2006, 08:51 AM

^^^ agreed, but the big disks sure do look cool. I just picked up some zimerman cross drilled rotors, but I did this purely for looks, as I am not a race driver.

Storamin · 05-02-2006, 09:14 AM

If your brakes can lock up your tires aka ABS kicks in, the tires are the bottleneck in your system. Almost all the time the tires are the bottleneck.

**dinan540** · 05-02-2006, 09:28 AM

I picked up the e39 M5 calipers and rotors for $250. For new rotors on an M5, bavauto.com sells them for $250 per side. So, I got a good deal on the used ones. I spoke to Dave at zeckhausen.com and he has installed e39 M5 rotors and calipers on an e39 540i. I have cleaned up the calipers and will paint them sometime in the next several weeks. Then I will pick up some SS brakelines and do the front brakes on my car. Hopefully in time for the next track day.

Storamin · 05-02-2006, 12:25 PM

did you ever rebuild the calipers?

**euro driver e34** · 05-02-2006, 12:57 PM

calipers for regular bimmers(not m-series) seam pretty easy. Couldn't tell about the M calipers. Never touched them. At least not yet. When I'm at home I have a part time job at dealership in Germany, and you do a lot of brake work. So I do the work on a few calipers and rotrs

**dinan540** · 05-02-2006, 03:21 PM

I didn't rebuild them. They came off an M5 with 15,000 miles, so I didn't bother. The seals were intact.

**euro driver e34** · 05-02-2006, 03:28 PM

Ya, I see the point at 15,000 thousand miles I wouldn't bother either. Most of the cars I work on get used and abused, but not in a good way!