more talk on bigger brakes

[angrypancake]

I've been looking into a brake upgrade for a while now, and have poured over the charts that have been provided, the one on bmwe34.net etc. The conclusion is looking to be 850 single pot calipers. Looking on realoem, the price seems a bit prohibitive. Anyone have estimates what used calipers would be going for? Thanks

[MTechnik540i]

I've been looking into a brake upgrade for a while now, and have poured over the charts that have been provided, the one on bmwe34.net etc. The conclusion is looking to be 850 single pot calipers. Looking on realoem, the price seems a bit prohibitive. Anyone have estimates what used calipers would be going for? Thanks

Trick is finding them, really.

[BigKriss]

why 850i single piston brakes?

[BillionPa]

you will NOT be unhappy with M5 (3.6L) front brakes and 530i rear brakes, combined with stoptech lines, some good ceramic pads, and some DOT5.1 fluid.

dont forget speed bleeders!

oh, and those brass bushings are the ****!

[BigKriss]

Nat, maybe you can get some e32 brakes.

[Rigmaster]

I have a clean used set of 750il calipers if anyone is interested.






Bret.

[Brandon J]

you will NOT be unhappy with M5 (3.6L) front brakes and 530i rear brakes, combined with stoptech lines, some good ceramic pads, and some DOT5.1 fluid.

dont forget speed bleeders!

oh, and those brass bushings are the ****!

I guess I will ask more about your lifestyle, driving style, budgets for maintenance, time, down time for car, etc.

The e31 single pot calipers are very good. Though it uses the same piston size as the e34 M5 and stock e34 (FYI, e39s & e39 M5 uses the same size also), so the pedal travel will be the same. The e31 pads are more abundant than for any multi piston BMW caliper. Also, there has been some research/mods where some backing plate massaging for e39 540i, e39 M5, X5 etc....the V8 5-series....can fit into the e31 calipers. So much more types of pads available when balancing out your e34's brakes.

The e34 530i rear calipers are EXACTLY the same as the 6cyl e34s. The only changes were in the big V8s and the ///Ms. The single pot caliper rear big V8 and Ms do have a larger rear piston by 2mm, so pedal travel will increase slightly, and with less pedal effort. Don't be turned away as some drivers like this to better modulate in tricky corners. The increase in piston diameter brings more force to the rear pad. The M5 has a larger master cylinder.

I recommend not to use super blue fluid for street, instead use the Typ 200. It has the same amber color as stock so the blue doesn't dye the plastic and other components. The Typ 200 has the exact same properties as the Super Blue.

As far as brass bushings, they are bad news for the street. Yes they will have better feel initially, but are made for the track. On the street a little bit of give is good for driveability, safety, and as well as performance. If you aren't inspecting the rotors/pads before and after everytime you drive (like in racing applications), then you will want a good set of new oem bushings. The rubber will be new, harder than the old ones, and quieter. The rubber also wears better and lasts longer than the brass bushings.

So, now you can see what you need to get a good basis for your brake upgrade and where you can tweek parts to find the best balance and suitability for your needs.

Good luck with your brake upgrade.

[BillionPa]

the reason i suggest the solid rear rotors is because it lowers the inertial of the rear wheels, actually making it easier to stop the car and accelerate over ventilated, and the decrease in heat dissapation is negligable unless you are tracking the car, and if you get cryo treated rotors they will be able to stay the right shape at higher temps...

only reason to get ventilated rears is if the car gains some weight or you have ever had brake fade in the rear with solid rotors (not likely)

and the reason i recommend the M5 front brakes over the 850s is because there is only a 3% decrease in torque applied to the rotor, and the calipers are a LOT easier to get a hold of.

after 2 years superblue has yet to leave any sort of stain on my reservoir. i use typ200 when flushing so i can tell when all the old blue is out.

so far with the brass bushings, other than regular moly based lubrication, they are better. twice a month i clean the brake dust off em and apply new lithium moly complex to keep em sliding. When i replace them, i will probably have the guide pins coated in tungsten disulfide and the brass coated in titanium nitride.

pedal feel is VERY consistent at the front, applying the brakes with the hand off the wheel keeps the car straight on a straight road. i do feel the increased vibration from the slotted rotors im using, as they arent absorbed at all by the brass. but it is very easy to tell how hard the brakes are actually working by the sound.

my ideal setup would be:
M5 front, stock rear, polymer coated at goldline. carriers xylan coated.
ATE powerdisk slotted rotors, milspec cadmium plated, cryo treated at diversified cryo, then thermal barrier coated where it meets the bearing hub (but not the wheel).
stoptech flexible lines, new steel lines on the trailing arms, 750i master cylinder ( i like the pedal sharp, if you dont this aint for you), Mutol RBF600 fluid, coated brass bushings front, rubber rear.

[BigKriss]

Have you installed the 750i master cylinder? I've asked about this before, but could never get a straight answer.

stoptech flexible lines, new steel lines on the trailing arms, 750i master cylinder ( i like the pedal sharp, if you dont this aint for you), Mutol RBF600 fluid, coated brass bushings front, rubber rear.

[BillionPa]

i have not, the sole function of the swap is to reduce the increased pedal travel caused by using "bigger" calipers.

E34 brakes have almost identical balance, but the position of the bigger calipers on the rotor requires a bit more pedal travel to apply the same torque(i think), even though the pistons are the same.

i also am not sure on how the 750i cylinder effects pedal travel on E34 brakes, as i dont know the variance between stock. but on E28 cars it reduces pedal travel by 10%. the bigger the piston, the less pedal travel. since i dont know the E34 stock piston size, i have no idea what the 750 one would do.