Intro & big brake questions

[Jake]

Hello everybody.

I'd like to say hi and thanks for providing a place to talk shop about our E34's. I'm US Air Force stationed in the UK and a confessed BMW nut. I started with an E30 323i about 5 years ago, picked up an E30 M3 about 4 years ago and now share my obsession with a constantly changing collection of E34's.

My first E34 was a 525iA (M20) that I picked up as a non runner and put back on the road. That one took me all over the UK and Europe. From towing an E30 M3 from Denmark to transporting family through Wales, Ireland and Scotland, that first E34 was a true work horse.

I'm now on my 4th E34 and have paused to turn her into something slightly special. She started life as a '93 530iT 5spd with the 3.0L M60 V8 and at some point received a 4.0L transplant. I've owned her for just over a year now and I'm in the process of correcting everything the previous owner sorta um.... well, half assed.

To make a long story short, someone stuck a 4.0L engine in her engine bay but neglected to upgrade all her supporting systems. I found that she'd been breathing through a 3.0L intake system to include everything from the airbox to the inlet manifold and exhaling through a 3.0 exhaust, headers to tail pipe. To my surprise, she even had the original 3.0L ECU!

So as things were beginning to get interesting I decided to get a bit more serious with this 'ol girl and do her the way the BMW gods intended, plus a little tweak here and there of course. You know the old saying, "while you're in there....", so this is where I'm at currently:

Intake system

- 4.0L specific cone filter and heat shield
- 4.0L MAF
- 4.0L throttle body
- 4.0L intake manifold

Exhaust system

- 4.0L headers, down pipe and cats
- Supersprint cat back system

Suspension

- Koni SA dampers front/rear
- Eibach Pro springs front/rear
- Racing Dynamics anti-roll bars front/rear
- Racing Dynamics strut brace
- BMW crash mounts (for more camber up front)
- Urethane front control arm bushes (thrust only)
- Note: self level eliminated

Misc

- 18 X 8.5 ACS replicas with Pirelli P Zero Nero 235/40ZR18

Soon

- Ignition Solutions coil on plug packs

At this point she's still on jack stands and I'm expecting to have her back on the road by the 1st of May. This project started in January when I needed to change a water pump and a self level hydraulic valve which quickly turned into a mod fest. I have a bad habit of going in to do something simple and then getting bit by the mod bug.

So anyway, now the dilemma; she still has the stock 530i brakes which use 302 X 22 vented front and 300 X 10 non vented rear rotors. I'm fairly confident they will be a bit overwhelmed with the additional output and handling. After all, BMW themselves saw fit to upgrade the brakes on the 540. I'd think a once 530iT now tweaked 540iT would need a bit of an upgrade over the stock 530i set up, especially as I will be tracking this pig on the Ring and various UK tracks.

And so the shopping begins. I'd prefer to stick with BMW if I can afford it. The write up on BMWE34.net has proved to be VERY useful. Thanks to the people responsible for that awesome collection of E34 info. The two obvious options from BMW stack up like this:

Full E34 M5 Nurburgring package -

Front - 345 X 32 floating rotors with 4 piston calipers ($$$!)
Rear - 328 X 20 non floating rotors (vented) with single piston calipers

~ or ~

Late 850/840 spec fronts with M5 3.6/540 rears

Front - 324 X 30 non floating rotors with 4 piston calipers
Rear - 300 X 20 non floating rotors (vented) with single piston calipers

The standard 540 stuff runs with 302 X 28 fronts with 300 X 20 rears. Compare that to the standard 530i stuff I currently have which will now need to control a slightly uprated 540iT bouncing on a modest suspension upgrade. I could just find a used 540i set up but then we come back to... "while you're in there...". I just may as well uprate while I'm at it.

Of course I'd really like the full Nurburgring package but that's a hell of a price jump from the 850 front/540 rear set up and I'm not sure it's justified. There is one other option that I find very interesting but I have a few doubts. It comes from Ireland Engineering as a front/rear kit for about $2100 and comes with:

Front - 334 X 32 non floating rotors with single piston calipers
Rear - 328 X 20 non floating rotors (vented) with single piston calipers
Plus - Pads, brake lines ect...

This set up is VERY attractive as it's big and cheap, but I'm just not sure how those fist type single piston calipers are going to feel up front and how compatible they are with the stock master cylinder. Last thing I want is to go cheap at the expense of crappy feeling brakes. No matter if they never fade, they need to "feel" good too.

So does anybody have experience with the kit from Ireland Engineering? My priorities are:

#1 - Increase fade resistance (I've had fade on the current set up during simple spirited road trips before uprating output and suspension)
#2 - Not break the bank
#3 - Maintain or improve feel

Well I think I've gone on long enough. Thanks for the space here and I appreciate any input you all might have for me.

Cheers,
Jake Larsen

[AllanS]

Yeah, new calipers alone for the NBBring package are almost 800$ each (priced from BMA), and would require timely shipping from Germany, but they don't require carriers, so I guess you save in that regard

I tried pricing out the 850 front brakes, brand new, and they came at around 400$ per caliper and 150$ per carrier, so it's not a HUGE deal cheaper than the 4 pots. I ended up buying the single piston 850i brakes from Bruno on this forum (and using early 540/530 rear brakes, non vented, in the rear), for a great deal cheaper, and repainting them. Aside from a carrier bolt stripping out, they've been fantastic.

From what I've read (from Rob Levinson of UUC, in a thread in Bimmerforums), the PBR calipers in the Ireland Eng. kit are in some ways based on the ones that some models Corvettes used. UUC used them in one of their older kits before moving to 4 piston calipers. Once again, according to Rob Levinson, they're very nice, but firsthand experience would be a lot better, of course.

[Jake]

Hi Allan.

I don't know if you noticed but there are 4 pot 850 front calipers too. They run about $800 cheaper than the Nurburgring calipers (per set) but use a 324 X 30 front non floating rotor. The Nurburgring package uses the nice floating rotors with a hike in size as well at 345 X 32.

If it were only a choice between the 850 4 pots or the Nurburgring 4 pots, I'd just go for the 850's. Rotors for those 850 4 pots are about half the price as the big floaters, so running costs would be more affordable as well.

When it comes down to it, 850 4 pot fronts with 540/M5 (vented) rears costs around $800 more than the single piston front/rear set up from Ireland. It would be nice to have a factory brake set up but.... 800 bucks is 800 bucks.

Shipping costs will certainly come into play. I live in the UK so anything from the US (Ireland Engineering) is going to take more time and cost a fair chunk of change. Any factory option I'd go with could be picked up at my dealer next day. So I need to take this into consideration as well.

Cheers,
Jake Larsen

[AllanS]

I'm aware of the 4 pot 850i calipers, but they didn't really interest me- I don't take my car on a track, and find the single piston calipers to be more than sufficient.

Since you're in europe, have you considered the Mov'it brake kits? They're not really sold in the states anymore but, they run from 2300euros and up.

If I were in your shoes, I would try and figure out how much torque is given by the PBR calipers that the Ireland kit uses, and compare it to the 593lb/ft that the 4pot 850 calipers put out. I would assume that the PBRs put out more since they are single piston. Likewise, you could then compare the PBRs to the early single piston 850 calipers which produce 737lb/ft of torque.

[DrewZ]

It's good to see another 4.0l wagon with a manual tranny out there. My car also started out as a 530iT, but got a 4.0l and 6-speed transplanted into it. I put in factory sport springs with Boge shocks, factory 20mm rear sway bar with 25mm Dinan adjustable front bar. The ride is still very comfortable, but cornering and turn-in are nice and crisp. As for brakes, I have the E31 front Brembos with the 540 rears. The Brembos are aluminum and super light. The Nurburgring 4-pots are iron, so they're much heavier than the Brembos. Other things I like about the Brembo/540 setup are: there is (in comparison) a nice variety of pads available: Porterfield, Hawk, Mintex, etc.; rotors are cheap and easy to find; they fit under 16" wheels; and the setup does very well at the track.

My $.02
Drew Zacharda
6-speed Touring

Hi Allan.

I don't know if you noticed but there are 4 pot 850 front calipers too. They run about $800 cheaper than the Nurburgring calipers (per set) but use a 324 X 30 front non floating rotor. The Nurburgring package uses the nice floating rotors with a hike in size as well at 345 X 32.

If it were only a choice between the 850 4 pots or the Nurburgring 4 pots, I'd just go for the 850's. Rotors for those 850 4 pots are about half the price as the big floaters, so running costs would be more affordable as well.

When it comes down to it, 850 4 pot fronts with 540/M5 (vented) rears costs around $800 more than the single piston front/rear set up from Ireland. It would be nice to have a factory brake set up but.... 800 bucks is 800 bucks.

Shipping costs will certainly come into play. I live in the UK so anything from the US (Ireland Engineering) is going to take more time and cost a fair chunk of change. Any factory option I'd go with could be picked up at my dealer next day. So I need to take this into consideration as well.

Cheers,
Jake Larsen

[l8apex]

I've been using the front/rear PBR setup on my 1994 540i for two years now. I have no reason to change, as I am quite satisfied with my brake performance at the track.
These are TWO piston sliding-type calipers made of alloy material, so they aren't too heavy. They use brake pads from the C-5/Z-06 Corvette, so you can get just about any brand/compound pads that you want for a decent price.
You can also use 850/750 stock BMW discs with this application.
I had some initial problems with wheel clearance. The wheels I used first were 8.5 x 17'' Mille Miglia II-2, and had no clearance issues. I put on a set of BBS RKs in the same size, and they were too tight. An hour with an angle grinder on the calipers' projecting fins fixed this.
I would recommend using "Speed Bleeders" for the PBRs, or at least use thread sealing compound on the bleeder threads, as air has a tendancy to leak past the threads when you crack the bleeders. I have had good luck with the Speed Bleeders.

Cheers,
Dave Brennan

I'd like to say hi and thanks for providing a place to talk shop about our E34's. I'm US Air Force stationed in the UK and a confessed BMW nut. I started with an E30 323i about 5 years ago, picked up an E30 M3 about 4 years ago and now share my obsession with a constantly changing collection of E34's.

My first E34 was a 525iA (M20) that I picked up as a non runner and put back on the road. That one took me all over the UK and Europe. From towing an E30 M3 from Denmark to transporting family through Wales, Ireland and Scotland, that first E34 was a true work horse.

I'm now on my 4th E34 and have paused to turn her into something slightly special. She started life as a '93 530iT 5spd with the 3.0L M60 V8 and at some point received a 4.0L transplant. I've owned her for just over a year now and I'm in the process of correcting everything the previous owner sorta um.... well, half assed.

To make a long story short, someone stuck a 4.0L engine in her engine bay but neglected to upgrade all her supporting systems. I found that she'd been breathing through a 3.0L intake system to include everything from the airbox to the inlet manifold and exhaling through a 3.0 exhaust, headers to tail pipe. To my surprise, she even had the original 3.0L ECU!

So as things were beginning to get interesting I decided to get a bit more serious with this 'ol girl and do her the way the BMW gods intended, plus a little tweak here and there of course. You know the old saying, "while you're in there....", so this is where I'm at currently:

Intake system

- 4.0L specific cone filter and heat shield
- 4.0L MAF
- 4.0L throttle body
- 4.0L intake manifold

Exhaust system

- 4.0L headers, down pipe and cats
- Supersprint cat back system

Suspension

- Koni SA dampers front/rear
- Eibach Pro springs front/rear
- Racing Dynamics anti-roll bars front/rear
- Racing Dynamics strut brace
- BMW crash mounts (for more camber up front)
- Urethane front control arm bushes (thrust only)
- Note: self level eliminated

Misc

- 18 X 8.5 ACS replicas with Pirelli P Zero Nero 235/40ZR18

Soon

- Ignition Solutions coil on plug packs

At this point she's still on jack stands and I'm expecting to have her back on the road by the 1st of May. This project started in January when I needed to change a water pump and a self level hydraulic valve which quickly turned into a mod fest. I have a bad habit of going in to do something simple and then getting bit by the mod bug.

So anyway, now the dilemma; she still has the stock 530i brakes which use 302 X 22 vented front and 300 X 10 non vented rear rotors. I'm fairly confident they will be a bit overwhelmed with the additional output and handling. After all, BMW themselves saw fit to upgrade the brakes on the 540. I'd think a once 530iT now tweaked 540iT would need a bit of an upgrade over the stock 530i set up, especially as I will be tracking this pig on the Ring and various UK tracks.

And so the shopping begins. I'd prefer to stick with BMW if I can afford it. The write up on BMWE34.net has proved to be VERY useful. Thanks to the people responsible for that awesome collection of E34 info. The two obvious options from BMW stack up like this:

Full E34 M5 Nurburgring package -

Front - 345 X 32 floating rotors with 4 piston calipers ($$$!)
Rear - 328 X 20 non floating rotors (vented) with single piston calipers

~ or ~

Late 850/840 spec fronts with M5 3.6/540 rears

Front - 324 X 30 non floating rotors with 4 piston calipers
Rear - 300 X 20 non floating rotors (vented) with single piston calipers

The standard 540 stuff runs with 302 X 28 fronts with 300 X 20 rears. Compare that to the standard 530i stuff I currently have which will now need to control a slightly uprated 540iT bouncing on a modest suspension upgrade. I could just find a used 540i set up but then we come back to... "while you're in there...". I just may as well uprate while I'm at it.

Of course I'd really like the full Nurburgring package but that's a hell of a price jump from the 850 front/540 rear set up and I'm not sure it's justified. There is one other option that I find very interesting but I have a few doubts. It comes from Ireland Engineering as a front/rear kit for about $2100 and comes with:

Front - 334 X 32 non floating rotors with single piston calipers
Rear - 328 X 20 non floating rotors (vented) with single piston calipers
Plus - Pads, brake lines ect...

This set up is VERY attractive as it's big and cheap, but I'm just not sure how those fist type single piston calipers are going to feel up front and how compatible they are with the stock master cylinder. Last thing I want is to go cheap at the expense of crappy feeling brakes. No matter if they never fade, they need to "feel" good too.

So does anybody have experience with the kit from Ireland Engineering? My priorities are:

#1 - Increase fade resistance (I've had fade on the current set up during simple spirited road trips before uprating output and suspension)
#2 - Not break the bank
#3 - Maintain or improve feel

Well I think I've gone on long enough. Thanks for the space here and I appreciate any input you all might have for me.

Cheers,
Jake Larsen[/QUOTE]

[Jeff N.]

Gee...a sibling for Frankenwagen! Purdy cool.

[Jake]

Since you're in europe, have you considered the Mov'it brake kits? They're not really sold in the states anymore but, they run from 2300euros and up.

Yes actually. I checked with Steve D at Ultimate Garage and he quoted me $6500 for a front/rear kit. My poor wallet about keeled over. I knew they were expensive and I'd maybe save a bit by going through a Euro supplier, but at that price, it would have to be one hell of a savings for me to even consider the Movit set up.

If I were in your shoes, I would try and figure out how much torque is given by the PBR calipers that the Ireland kit uses, and compare it to the 593lb/ft that the 4pot 850 calipers put out. I would assume that the PBRs put out more since they are single piston. Likewise, you could then compare the PBRs to the early single piston 850 calipers which produce 737lb/ft of torque.

Good point but I think there is more to it than just torque ratings. I think there are a several factors to consider when up rating your braking system (not necessarily in this order):

- Overall rotor mass/design (which dictates fade resistance to some extent)
- Caliper torque (to obtain the correct front/rear bias)
- Hydro mechanical relationship between the master cylinder and caliper (dictates pedal travel and to some extent, feel)
- Running costs (replacement rotors, pads, ect..)
- And of course, initial cost

After this, fine-tuning can be accomplished with pad choice. Initial bit, heat range, ect..

I think anything above E34 M5 (3.6) spec brakes would have more than enough mass to keep brake fade at bay, but that's just my personal opinion; that's as small (rotor wise) as I'd like to venture.

Compatibility with my stock master cylinder, as far as volume is concerned, is another detail I feel I need to pay attention too. If I choose calipers that require much more volume to operate, I'm going to have excessive pedal travel; very bad for pedal feel. The problem is I don't even have the info on any of these calipers to compare them against each other.

I consider the Nurburgring spec to have the ideal brake bias for no other reason other than I see them as the last variation applied to the E34 chassis. The last and probably better-designed setups, if that makes sense. So I'd like to stick close to this front/rear bias if I can.

I think the explanation on BMWE34.net is right on as far as brake bias is concerned but the comment made about why that set up "feels" so good may be off a bit. Feel is all about what comes through that pedal. There are several factors that influence this and most importantly, the hydo mechanical couple between the master cylinder and caliper.

Brake bias effects how the car handles under braking but doesn't directly relate to brake "feel". This is the only part I disagree with in this otherwise awesome write up on BMWE34.net under "bigger brakes" (http://www.bmwe34.net/e34main/upgrade/brakes.htm).

Dave Brennan,

Thank you very much for your very insightful take on the PBR set up. It's definitely one of my top choices after reading your input. Really, the only problem I have is that I'm ONLY in sync with BMW so a factory option sounds like the easiest to digest. But I know I shouldn't limit myself like that.

It's good to see another 4.0l wagon with a manual tranny out there.

Ahh yes. All the convenience of a wagon wrapped up in a very inspiring chassis. Can't beat it. Manual is the only way to go! I get depressed without that sensory input.

My car also started out as a 530iT, but got a 4.0l and 6-speed transplanted into it.

I remember looking at your car online a few months ago. Well done! Sounds like it was a really fun project!

I put in factory sport springs with Boge shocks, factory 20mm rear sway bar with 25mm Dinan adjustable front bar. The ride is still very comfortable, but cornering and turn-in are nice and crisp. As for brakes, I have the E31 front Brembos with the 540 rears.

I'm leaning towards this set up over the PBR's actually. If I can find the calipers used then I think I'm sold. If not though, those PBR's just might have to do the trick.

The Brembos are aluminum and super light. The Nurburgring 4-pots are iron, so they're much heavier than the Brembos.

Yah, I noticed that in the ETK. Something like 6.??lbs for the Nurburgring 4 pots but only 3.?? for the 850 Brembo's. That's very interesting.

Other things I like about the Brembo/540 setup are: there is (in comparison) a nice variety of pads available: Porterfield, Hawk, Mintex, etc.; rotors are cheap and easy to find; they fit under 16" wheels; and the setup does very well at the track.

So one each thumbs up for the PBR's and the 850 4 pot/540's. It's going to come down to cost I suppose. Anybody else have input or personal experience with these two set-ups?

Thanks again guys. Great discussion!

Jake Larsen

[DrewZ]

I'm leaning towards this set up over the PBR's actually. If I can find the calipers used then I think I'm sold. If not though, those PBR's just might have to do the trick.

I picked up my used Brembos for about $500, IIRC. They're very hard to find used here in the US; maybe you'll have better luck over there. There's another US serviceman stationed in Europe (Duke from the E28 forum) that was able to get new Brembos from the BMW dealer for something like $750/pair. (Helluva price considering Dinan sells the same brakes as their "Stage 1" kit for $1800!)

I've seen the PBRs in person when UUC was selling those. I was considering getting them instead of the E31 brakes. I tried on several different 16" wheels over the PBR fronts. Since none of them quite fit, I went with the E31/540 setup. (I drive the car year-round, and don't want to spring for 17" winter tires, thus the 16" wheel requirement.)

Drew Zacharda
6-speed Touring

[Jake]

I picked up my used Brembos for about $500, IIRC. They're very hard to find used here in the US; maybe you'll have better luck over there.

Weird coincedence. LOL I just made a $500 offer for a used set from a friend in Germany. He has a set he was going to adapt to an E30 M3. Guess he just changed his mind and now doesn't need them.

Finding rear M5/540 calipers proved to be very easy so if my German buddy bites on my offer I think I'll be set. I'll pick new rotors up from the dealer but I need to figure out what to do for pads. Any suggestions? It would be fun to run race pads on the track and then swap out for the drive home (assuming I don't pack her into an armco somewhere).

Oh yah, one other thing. I already have a Goodridge SS brake like kit for my stock brakes. Anybody know if those 850 front 4 pots have the same line connection as the E34 fist type fronts? Hate to let those go to waste.

Again, thanks everyone for your help with this.
Jake Larsen