Can you buy any set of good brake callipers, whether from EBay or new from a dealer, and get a bracket made up to fit any car, subject to size/space restrictions? I just wonder because you see calipers for sale, but rarely specifically for an E34 M5. Is it just the bracket that makes the callipers model specific?
No offence to OP offcourse, I respect the question but it's too scary to answer. And being in the UK means you have AP, Tarox and Wilwood available everywhere and Movit available through DickRS on here or Benjamin in the UK. Why chance it?
__________________
Dragracing a BMW is like taking Jessica Alba fishing. Some might considering it fun, but think of what they missed....
yes you can,i used a pair of ap racing calipers cp5551 as ap reccomend for the specific upgrade kit. i also used e39 m5 discs and machined brackets myself although most good engineering shops would do this for you.
also have 4 pots for the rear but still have to source handbrake shoes/backplates for the e39 rear discs.
in my opinion its the best upgrade the car needs,even the 343 4 pots cant cope with the cars weight on the ring.
mine has now done over 50 laps with these on the front and ive done 8 laps back to back, with the rears done it should be perfect
I readily accept that I know very little about what can and can't be done here, which is why the question. And ultimately whatever gets done won't get done by me because if it did, I'd end up embedded in a tree somewhere in the English countryside. That doesn't stop me working out what I want someone else to do for me though, or at least having some ideas.
As far as I can see, these are the issues:
1. Clearance - will the callipers and discs physically fit under the wheels. I'm running 18" Hartge wheels, so I'm thinking most callipers will. I'm guessing the wheel offset might also be a factor, possibly meaning spacers. Not at all sure on that as steering geometry could be adversely affected?
2. Mounting - Brackets are unlikely to be available, so will need fabricating. Not something I could do, but I know a man who can, so that should be relatively easy. Probably / maybe.........
3. Discs - Larger callipers have a minimum disc size requirement as well as a maximum. BMW have the later 343 x 32 floating discs, but does anyone sell larger discs, say 355? Will discs specified for other BMW models fit? Ian used E39 M5 discs, so I assume at least some will. The bolt patterns are the same, but are the hubs different sizes and what other factors kick in?
4. Pipes - I'm not sure how much play there is in model specific pipes, but worse case scenario is that some need making up. I don't imagine that will be the biggest problem.
5. Brake bias - Really exposing my ignorance now, even more than above. I have no idea whether this is controlled by the performance of the components at either end, or whether the system adjusts in some way. I'm guessing it is led by the components, so now the bias is out and at some point the rear needs improving. Hopefully better discs and pads are a decent halfway house, or even bracket spacers and a slightly larger rear disc.
6. Performance - If the callipers are upgraded too much with too many pistons, does everything else need upgrading to get the fluid to all the lovely new pistons?
There are probably lots of other factors, mostly more important than those that I can think of, but having impulsively bought a set of enormous 6 pot Alcon callipers, (EBay is a terrible thing when you're bored), I'm kind of inclined to see if I can make it work. No problem if not, I'll sell them and take my loss, but it's always worth a shot. Even though it will probably end up costing the same as AP!
Don't take Stevie's sharpness personally - he usually has good points to make with little time to do it!
But he's right in that you cannot buy 'any set of good brake caliper'.
Companies like APR and MovIt offer matched sets of front and rear calipers and discs for E34 M5s (as do others) - not sure if mounting brackets are needed/included. But in some countries such brackets are in fact illegal!
Do a search there are many threads on brake upgrades. Good luck!
__________________ Look on the bright side, if I don't drive it for a year (2 years) the engine rebuild will pay for itself.(I'll make a profit!!).
As Stevie mentioned there are plenty of very good brake manufacturers that offer BBK's (Big Brake Kits) for the E34 M5. These are made specifically for the car and are a simple bolt on job. I would go for a kit from AP Racing or Mov'it, as I have only heard good things about their kits. Check out this link for a nice Mov'it setup on a famous E34 M5: movit - the high performance brakes for BMW E34 M5
Another thing to keep in mind is the intended use of the setup. Track or street? Personally I find the OEM setup satisfactory for street use.
When it comes to brakes, it really boils down to safety. I would not replace my OEM setup with some cheap aftermarket calipers just because they look better, combined with drilled discs (that are prone to cracking if not cast from factory). Save up and go for a tried and tested kit made specifically for the E34 M5.
Another thing to consider; I believe APR calipers don't come with dust seals (please correct me if I'm wrong), so ongoing maintainence is also a consideration.
__________________ Look on the bright side, if I don't drive it for a year (2 years) the engine rebuild will pay for itself.(I'll make a profit!!).
The standard brakes are a weak point on the car, and will be getting changed at some point. The later, larger set-up is better by every account, but costs as much from BMW as any of the BBK kits available, so probably drops out of contention against better alternatives.
This wouldn't end up being a cheap or cost cutting 'bling' option with questionable quality discs. Alcon are as good as any aftermarket calliper, and significantly better than most. My partner had a Ford Racing Puma with the Alcon race brakes, (so yep, no seals on that one), and they are eye-poppingly good, hour after hour, so long as they are looked after. Yes they need an annual service, but nothing good is cheap. Clearly that is a different car with different size brakes, but the quality of those brakes is beyond doubt.
I believe most Alcon callipers do use a seal, it is their race callipers that don't. Certainly they sell seal kits for them. Whatever Alcon are, they are not merely window dressing.
If it happens and if it goes according to plan, they will be stunning brakes. If not, live and learn.
Sorry! I guess it wasn't a PC day today..... 
Linear Mode
