# Brake upgrade question



## dchen (Jul 2, 2002)

Is it possible to upgrade the e39 540i brakes to the e60 545i brakes? Or is it easier to upgrade to M5 brakes? My 03 540 brakes look pretty small behind the M parallels that came with the car.


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## DSPTurtle (Oct 4, 2003)

Wow... good question. Are the 545i brakes any bigger? DaveZ, didn't you already have one in for a CDV delete? Did you look at the calipers/rotors?
JB


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## DZeckhausen (Mar 11, 2003)

dchen said:


> Is it possible to upgrade the e39 540i brakes to the e60 545i brakes? Or is it easier to upgrade to M5 brakes? My 03 540 brakes look pretty small behind the M parallels that came with the car.


The hub diameter of the E60 is 1.6mm smaller than the E39, so, even if the rotors and calipers did bolt on, they wouldn't fit the hubs properly.

Upgrading to the M5 brakes would be easier. Don Jacobson ([email protected]) acquired M5 brakes, front and rear, for his 1997 540i, but then decided to install StopTech front brakes instead. You might try contacting him to see if he would part with the M5 front brakes at a reasonable price.

Alternatively, the Brembos and StopTechs fit behind the front wheels without spacers:









*Left front wheel of my 540i*


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## tsaros (Nov 24, 2003)

DZeckhausen said:


> The hub diameter of the E60 is 1.6mm smaller than the E39, so, even if the rotors and calipers did bolt on, they wouldn't fit the hubs properly.
> 
> Upgrading to the M5 brakes would be easier. Don Jacobson ([email protected]) acquired M5 brakes, front and rear, for his 1997 540i, but then decided to install StopTech front brakes instead. You might try contacting him to see if he would part with the M5 front brakes at a reasonable price.
> 
> Alternatively, the Brembos and StopTechs fit behind the front wheels without spacers:


I have allways wondered why you choose Brembos over Stoptechs on your own machine


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## dchen (Jul 2, 2002)

Thanks for the info Dave. M5 brakes looks like a good option although your Brembo brakes look way better. :thumbup:

I assume M5 rotor and calipers bolt right on. Do you need to change the master cylinder to handle the bigger brakes or will the one on the 540 handle it? Also in terms of brake feel, how does the M5 brakes feel compare to the Brembo/Stoptech kits?


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## DZeckhausen (Mar 11, 2003)

tsaros said:


> I have allways wondered why you choose Brembos over Stoptechs on your own machine


I started out with a 4-wheel Mov'it system on my 2000 540i/6. That car was destroyed in an accident, but the brakes were undamaged. So I swapped them into my new 2001 540i/6. Shortly after that, I started Zeckhausen Racing. It made sense for me to have one of the products I carry on my car, so I considered StopTech first. The fronts fit under the stock 17" Style 66M wheels without spacers, but the rear kit doesn't even come close. I really wanted to keep those wheels, so that nixed the StopTech kit. I installed the Brembo 4-wheel kit, but required 15mm rear spacers and 10mm front spacers. It worked, but I would get occasional fender rubbing in the back with passengers. Then BMW rolled out the 2003 540i/6 with 18" Style 37 wheels. I really liked the look, so I decided to update. An added bonus is that I could eliminate the front spacers and drop down to mere 3mm spacers in the back. Much better!

My Style 66M wheels, by the way, are listed in the 4-sale forum. See: http://www.bimmerfest.com/forums/showthread.php?t=53796 :thumbup:


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## DZeckhausen (Mar 11, 2003)

dchen said:


> I assume M5 rotor and calipers bolt right on. Do you need to change the master cylinder to handle the bigger brakes or will the one on the 540 handle it? Also in terms of brake feel, how does the M5 brakes feel compare to the Brembo/Stoptech kits?


The M5 brakes do bolt right on, although you won't be able to use a rotor retaining screw unless you change to the M5 front wheel bearings. The M5 uses a smaller 5mm retaining screw which does not have a countersunk head like the 6mm 540i rotor retaining screw. That's not a big deal. Plenty of folks are running around without retaining screws.

In order to retain the factory balance, you probably want to upgrade the rear brakes to the M5 parts. The master cylinder is the same in the M5 and the 540i, so there's no issue there. As for feel, there is not really any difference between stock 540i and M5 brakes. The systems use the same 1-piston sliding caliper design, so you won't end up with a firmer pedal. Basically, you are just buying yourself a bigger margin in thermal capacity as well as longer pad and rotor life. You're also hurting your acceleration and handling a bit, since the M5 rotors are several pounds heavier and have greater rotational inertia. I've heard from several 528i owners who upgraded to M5 brakes and really noticed the hit in performance. The difference is not so dramatic on the 540i.

The Brembo and StopTech brakes both significantly REDUCE the weight of the calipers and the rotors. Install one of those systems and slap on a set of lightweight SSR competition wheels and you are going to notice a difference!


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