Brake Upgrade, E34-540 to 850CSi

[Porschmn]

Has anyone upgrade to the 850CSi brakes? I want to be sure they will fit before I purchase them.

[632 Regal]

why?

[Porschmn]

I am unsure of the question. Why the upgrade?

[632 Regal]

Yes exactly

[BigD]

I haven't but here are a few words of wisdom from a friend who races an M5 and has tried it all. He thinks the 4 pot brembo 840i brakes are ideal for this car. The 850CSi are a bit bigger and stronger but the discs are CRAZY expensive (not that they're cheap for the 840 setup, or even on my 3.6 M5 for that matter, but take that to the next level). More importantly for the performance freak, they are heavier. The Brembos are aluminum and are about a pound lighter than the 850CSi, so you are saving a lot in unsprung weight.

Also, I'm not 100% sure (if you still need to know, I'll ask him when he gets back) but I think he said that unlike all the other potential setups, you need to modify the tower to take the 850CSi calipers.

Has anyone upgrade to the 850CSi brakes? I want to be sure they will fit before I purchase them.

[Porschmn]

I just got this car, or I should say I just bought one and it will be here in a couple of weeks. I am looking to upgrade the brakes to accomodate the ESS super charge that the car will get.

[Porschmn]

Big D, I would like to know. If you would ask him I would be appreciative. I can get them no problem I just want to be sure before I spend the money.

[DrewZ]

Euro 850CSis got huge 345mm front brakes with iron 4-pot calipers (same as the '95 euro M5). US 850CSis got 324x30 rotors with iron single-piston calipers (same as on the regular 850i). 840Cis got 324x30 rotors with aluminum 4-pot Brembos. Both versions of the 324x30 front brakes are a direct bolt-on upgrade for an E34 (I've had both on my Touring).

Now tell us more about the ESS project . . .

Drew Zacharda
6-speed Touring now with E31 4-pot Brembos

I haven't but here are a few words of wisdom from a friend who races an M5 and has tried it all. He thinks the 4 pot brembo 840i brakes are ideal for this car. The 850CSi are a bit bigger and stronger but the discs are CRAZY expensive (not that they're cheap for the 840 setup, or even on my 3.6 M5 for that matter, but take that to the next level). More importantly for the performance freak, they are heavier. The Brembos are aluminum and are about a pound lighter than the 850CSi, so you are saving a lot in unsprung weight.

Also, I'm not 100% sure (if you still need to know, I'll ask him when he gets back) but I think he said that unlike all the other potential setups, you need to modify the tower to take the 850CSi calipers.

[Bruno]

Yep Yep Yep....

[Bruno]

If you read BMWE34.net, all the info with part# is there.