All about BMW: BMW DIY, BMW series, BMW photos, BMW reviews...

Brake upgrade on e34

Cost: $300 - $900

Difficulty:

BMW E 34 M5 "Formula 1" with OZ 18" rims and Porsche GT2 front brakes only by mov´ it worldwide

When the Bmw E34 was produced, it was the sedan that had the shortest braking distance. If I count the number of times people have almost rear ended me... looks like they are not used to it.
But because we love to race our babies too, upgrading the brakes is something to keep in mind. The cheapest way to do it is to use the brake components from an E32 740i or an E34 540i.

E28 and E34 have identical brake fitment.
Here is info about stainless steel brake lines.

Procedure from Rob Levinson (updated by Nick)

Try to find the calipers and brake carriers in a junk yard and buy new rotors and pads. For any of the bigger factory brake option, you need the correct carriers for the specific calipers/rotors.

Front Brakes
E34 540i, E32 735i-il, 740i-il, 750il, front brakes will fit the E34.
E32 front brakes are an upgrade for non M5/M540i, but the real front upgrades are the E31 and E34 M5. 324mm needs 16"wheels and 345mm fits under 17" wheels. Everything in the table will fit:

Bmw Model
Rotor size
Rotor part#
Caliper part# L/R
Clip part#
Carrier
E32 730i (L6&V8)
E34 525i-535i-530i
V 302 x 22
34 11 1 160 936
34 11 1 160 367/368
34 11 1 157 687
34 11 1 160 366
E32 735i/il L6
E32 740i/il-750i/il
E34 540i
V 302 x 28
34 11 6 756 090
34 11 1 160 363/364
34 11 1 157 687
34 11 1 160 365
E34 M5 3.6
V 315 x 28
34 11 2 226 385
34 11 2 226 873/874
34 11 1 157 687
34 11 2 226 875
E31 840/850Csi**
V 324 x 30
34 11 1 159 895
34 11 1 160 325/326
34 11 1 159 957
34 11 1 160 327
E31 840/850***
V 324 x 30

34 11 6 756 087
34 11 1 161 086

34 11 1 16 177/178
none
4 piston callipers
E34 M5 3.8 ('95)
V 345 x 32
34 11 2 227 735/736
34 11 2 227 115/116*
34 11 2 227 506
Requires 17" wheels
* 4 piston calipers, integral carrier V: ventilated
** 93-95 for the US 850Csi and up to 08/93 for other US models.
***840 - 850 from 08/93 on

The larger Euro M5 brakes came standard on the Canadian model M540i. They weren't included on the U.S. 540i Sport model for litigious reasons, i.e. the aluminum floating rotor that requires periodic inspection for cracking. It was deemed US owners would ignore that service and end up maiming themselves and suing BMW. (Thanks David)

Rear Brakes (updated thanks to Gregory B. and Nick)
735il rear brakes will not fit the E34. E32 rear rotors will not fit the E34. However the 750i/il, 740i/il (and 540i) calipers and carriers can be bolted on the E34 when used with 540i rotors.
No E31 rear callipers fits the E34 but the 324x12 non vented rotor will fit. Everything in the table will fit:

Bmw Model
Rotor size
Rotor part#
Caliper part# L/R
Clip part#
Carrier
E34 525-535-530
300 x 10
34 21 1 162 305
34 11 1 160 381/382
34 11 1 157 046
34 11 1 160 383
E34 540i
V 300 x 20
34 21 1 159 659
34 21 1 160 399/400
34 21 1 157 046
34 11 1 160 384
E32 730i/il
L6 & V8
300 x 10
34 21 1 165 259
does not fit
34 21 1 160 381/382
34 21 1 157 046
34 21 1 160 383
E32 735i/il &
some L6 730i/il
300 x 12
34 21 1 165 257
not tested
34 21 1 160 353/354
not tested
34 21 1 157 046
34 21 1 160 355
not tested
E32 740i/il
E32 750i/il from 1/90
V 300 x 20
34 21 1 162 967
does not fit
34 21 1 160 399/400
34 21 1 157 046
34 11 1 160 384

E32 750i/il
to 1/90

V 300 x 20
34 21 1 162 967
does not fit
34 21 1 160 385/386
34 21 1 157 046
34 11 1 160 384
E34 M5 3.6
V 300 x 20
34 21 1 159 659
34 21 1 160 399/400
34 21 1 157 046
34 11 1 160 384
E34 M5 3.8 ('95)
V 328 x 20
34 21 2 227 844
34 21 1 160 233
34 21 2 227 873/874
34 21 2 227 672
34 21 2 227 875

V: ventilated

E39 M5 brakes definitively do NOT fit the E34. Rob tried a set last summer, BMW moved the carrier mounting holes about 2mm further apart. The rotors also do not have the dual 18mm posts required to fit the E34 M5 hubs.

Cross drilled rotors are a waste of money, if you want to use your E34 on the track you can consider the ATE slotted rotors. If you want the ultimate in braking and have 17" wheels, consider upgrading to the Mov'it/Porsche kit. Check ultimate garage.

Brake balance: front/rear:

The type of brakes you install on your car has a large influence on how the car feels and handles, especially when driven hard. BMWs with semi-trailing-arm rear suspension tend to have some squat under acceleration and a certain amount of dive under hard braking.
For example, certain choices of front or rear brakes will increase the front brake bias over stock, which will obviously exacerbate the brake dive problem--not a good thing! Changing the bias will also affect the car's susceptibility to having the ABS kick in prematurely on the front or rear axle. Finally, it affects pedal travel--a lower-torque brake setup will require more pedal travel for the same amount of braking force compared to another setup. Even if you change the front and rear brakes simultaneously and maintain something close to the stock bias, if the new brakes are lower torque than the stock brakes you'll end up with more pedal travel. With some cars this can even mean having to change the master cylinder to a higher-volume unit.

To give an example, the E34 540i brakes develop 686 lb-ft of torque on the fronts at 500 psi line pressure; the rears produce 313 LB-ft, so the f:r bias is 69:31 (as a percentage). Adding the M5 front brake (rears are the same on US E34 M5's), which generates 720 LB-ft, changes the bias to 70:30. The '95 Euro M5 brakes generate 646 LB-ft front and 336 LB-ft rear, giving a bias of 66:34. Everyone raves about this setup, which is interesting as the front brakes actually generate LESS torque than the earlier E34 M5 (or the 540i, for that matter)! Chances are that this perception of awesome brakes has more to do with the better balance front-to-rear than the massive cooling capability, which only comes into play when you're driving the piss out of the car and the brakes are generating many kilowatts of heat. Unless you go to the track, you'll never encounter that aspect of their performance.

Here's where it gets interesting: the 850i single-piston front brake (like I have) generates 737 LB-ft, the highest of any BMW brake I know of. I assume you put the 540i rears (313 LB-ft) on your car, so the bias is 70:30, same as the US E34 M5. However, if you instead use the later 840i/850i (not CSi) brakes, which generate only 593 LB-ft of torque, the bias would be 65:35--very close to the Euro '95 M5 brakes. I believe, though haven't proven it yet, that this might be the ideal setup for the majority of E34 owners who don't want to spend the huge bucks for the '95 M5 brakes. It's still not cheap, but it's half the price of the alternative.

Street Pads

Raybestos pgplus:
Improvement over stock, stop well , quiet, no dust... Much better than the metal master pads.

• PBR - Repco - Axis Deluxe:
Good pads for non aggressive street driving. Low dust. Might squeal a little. Not suited for extreme or track use.

• EBC GreenStuff:
Kevlar compound pads for non aggressive street driving. Low dust.

Street Pads, may be used on track

• Stock Pads:
Fine on street, decent on track. Dusty pads. Can overheat by a strong intermediate or advance driver.

Raybestos QS series which is the ceramic:
Improvement over stock, stop well , quiet, no dust.... but the QS ceramic raybestos seems to be a big step better than the pgplus.

• PBR - Repco - Axis MetalMasters or EBC RedStuff:
Average pads for aggressive street driving, after little warm up. Low dust. Tend to squeal. Better choice than the Deluxes on track.

• PBR - Repco - Axis Ceramic
New compound yet to be tested

• Pagip:
German sport pads for street use. Exact fit. Dusty pads. Work better than stock on track.

• Performance Friction Z-rated:
Good street/track pad. Better bite and less dust than stock. Needs little warm up.

• Performance R4S:
Carbon Kevlar street/track pad. Impressive bite and heat resistance. No warm up needed.

• Carbotech Panther:
Street/track pad. Good bite, resistance to fade, quiet.

Track Pads (not suited for street use)

•Porterfield R4 or EBC YellowStuff:
Carbon Kevlar pad. Great bite, fade resistant. Squeal a bit under light braking.

•Performance Friction 90:
Racing brake pad used in GT2, GT3 racing. Great braking power and fade resistance. Last's long.

•Hawk HT10:
Strong braking, heat resistance, noisy and dusty. Warm up needed for max efficiency.

Be sure to change the brake fluid annually using BMW Brake fluid or ATE SL Dot 4. Racing fluid like ATE Super Blue or AP racing 5.1 and 600 (available at Raven) are designed to be used in extreme track conditions, but tends to be more hygroscopic than the street brake fluid.