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How-to: Cheap brake upgrade

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ZetaTre
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How-to: Cheap brake upgrade

Post by ZetaTre » Wed Jan 07, 2009 1:37 am

A problem I've noticed with the brakes of my roadsters is not so much braking power but heat dispersion. I recently upgraded the brakes on the Z3 after get them hot to the point of not being able to stop while trying to keep up with IMZ4N (it's always his fault if I have to upgrade something :poke: ). The Z3 came with 286mm SOLID front rotors and was able to upgrade them to 300mm VENTED for $160 (plus new rotors, but that's more of a maintenance item).
Bigger brakes run cooler because they require less friction to generate the same torque. If you're thinking about upgrading your brakes to increase braking power, first make sure you're ABS doesn't kick in already; if it does, then your problem is more so with tires and suspensions, than brakes (or at least, brakes are not the place to start from)...

I've being doing some research about doing something similar on the Z4 and I thought I would share some thoughts since I read of people asking about it:
1) The 2.5i (as well as the Euro version 2.0i and 2.2i) have 286mm vented in the front and 280mm solid in the rear
2) Both 3.0i (and the Euro 2.5si) have 300mm vented in the front and 294mm vented in the rear
3) The 3.0si has 325mm vented in the front and 294mm vented in the rear
4) The ///M have their own things, so it might not be as easy to put ///M brakes in a non-///M car (the different offset and the ///M tradition makes me think it require some suspension parts to be changed as well... The ///M experts might be able to help more)
5) 300mm is the most you can fit with 16" rims; 325mm require 17" rims
6) All Z4 share the same master cylinder (although the p/n changed they are interchangeable): this simplifies the swap a lot.
7) The Z4 share the same brakes as the E46, making a lot easier to find parts at the junkyard

I would recommend you grab the whole caliper and carrier assembly by removing the brake fluid line and the two bolts connecting the carrier to the king pin/suspension. This doesn't apply only if you're planing on upgrading from 286mm to 300mm front: if so, all you need is the carrier (calipers, sliders and clip are the same). Remember that if you have 16" front rims, 300mm is the biggest you can go without having to change your rims.

Upgrade combinations

300mm vented front brakes
This is a good upgrade for the 2.0i, 2.2i and 2.5i. It will allow you to keep the stock 16" rims and you'll keep a good front-rear brake bias. The cheapest way to go...
All you need is the carrier and can be taken off the following cars:

E46 318d Touring
E46 318i Sedan
E46 320 All (Gasoline & Diesel)
E46 323i Convertible & Touring
E46 325i All
E46 328i All
Z4 3.0i Roadster
Z4 2.5si Roadster
Z3 3.0i (Roadster & Coupe)

325mm vented front brakes

This is a great upgrade for all Z4: you'll have the same front brakes as the 3.0si so I'll recommend upgrading the rear to 294mm. You will need 17" to clear the calipers.
You'll need the whole front caliper assembly from one of the following car:

E46 330i All
Z4 3.0si (Roadster & Coupe)

If you wanna be a perfectionist: the protection plate behind the 325mm rotor is bigger than what the 300mm or 286mm have (these two setups have the same cover). The rotors should fit with no particular issue as the cover does not interfere with the rotor. The problem with replacing this covers is that the wheel hub has be removed (you need a 46mm socket and an impact wrench) make it impractical if you are sourcing the parts from a junkyard. My friend Ed has been able to fit 325mm on a 323i Touring (originally equipped with 286mm as some Z4s) and had no issue. You can see some pix of his setup here.

294mm vented rear brakes

Another good upgrade for the 2.0i, 2.2i and 2.5i. It will allow you to keep the stock 16" rims and you'll have the same front-rear brake bias as the 3.0i.
If you go with 325mm in the front, I'll suggest you upgrade the rear as well to keep the bias within BMW specs.
You need the whole caliper-carrier assembly from one of the following cars:

E46 318d Touring
E46 318i Sedan
E46 320 All (Gasoline & Diesel)
E46 323i Convertible & Touring
E46 325i All
E46 328i All
Z4 3.0i Roadster
Z4 3.0si Roadster & Coupe
Z4 2.5si Roadster

320mm vented rear brakes

If you find a E46 330i, you might also want to consider a full brake setup off this car: it would give you 325mm in the front and 320mm in the rear and it would be a bolt on swap...
Alternatively, 320mm rear vented rotors can be sourced off of an X3 (any model, old or new). As noted below, the X3 might not be able to provide you a full front and rear swap: the front calipers are the same as the E46 330i, but the caliper carrier has a different p/n.
In summary, 320mm vented rear rotors can be sourced from the following cars:

E46 330i All
E83 X3 All

320mm can be used only with 325mm front as you don't want to have your rear rotors bigger than the front. Although many variables go into calculating brake bias, the disk size ratio of a 325mm front - 320mm rear conversion is similar to what the 3.0i has so it should be fine. However such a brake setup was never chosen by BMW as a setup for the any Roadster.

Another note regarding 320mm rear brakes. In this case too they have a different protection plate (as for the 325mm front rotors setup), and in this case it gets in the way of the bigger rotor. Once again, removing the plate is not as practical as you have to remove the parking brake assembly and likely the wheel hub. To fix the issue I would personally just bent the plate of the way... Sometimes I agree with the saying that "is something doesn't fit, your hammer ain't big enough"...

Notes and Credits

PS1: the E46 323i

I did some more research about the E46 323i and it appears to be somewhat in between when it comes to front brakes: some body style have 286mm while others have 300mm. Also it appears the same body style could have different configuration between Euro version and US version... I would recommend you bring some measuring tape when going shopping through junkyard just to make sure you get the correct one.

PS2: possible sources

IMHO, buying the calipers new from BMW is not cost efficient, as you might as well go with some fancy non-floating & multi-pistons brake kits. Here's a couple of hints of where to source the parts you need:

1) of course you can check with your local junkyard and car dismantlers: where I got mine the guy actually removed them, in some junkyard you remove the item yourself and then negotiate the price

2) eBay is a good source for the: the US has usually has a lot of calipers off of E46 so that's a source...

3) There are some dismantlers that specialize on BMW and will ship you the product. The two I can recommend because I have personally used are:
- Autobahn in El Cajon here in San Diego
- Bavarian Auto Recycling up in the Bay Area. The nice thing about them is that calipers come tested (the o-rings are replaced if leaking), cleaned, and come with a warranty (not sure of how long)... Of course they are more expensive than what you could get elsewhere.

Just complement any of these setup with some Brembo Slotted or Zimmerman cross drilled rotors (I got mine from Ed @ Bimmerbum). I won't recommend buying rotors on eBay as some sellers get plain rotors and drill them in house.

PS3: sourcing the front brakes from an X3

The X3 has the same front calipers as the 330i (325mm vented); however the carrier has a different p/n so it might not be a perfect bolt on.

Credits

cj10jeeper: comments on several things
mamasuon: comments regarding the dust plates on the 330i and Z4 3.0si being different
Last edited by ZetaTre on Thu Jan 08, 2009 10:24 pm, edited 12 times in total.
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2003 Z4 2.5i
2004 X3 3.0i
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cj10jeeper
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Re: How-to: Cheap brake upgrade

Post by cj10jeeper » Wed Jan 07, 2009 10:23 am

Tis is a really neat and well organised write up of the various stages of brke upgrade and components required :thumbsup:

Looks like I need to pencil the 325mm front conversion in for my 3.0i :)
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Re: How-to: Cheap brake upgrade

Post by t20lau » Wed Jan 07, 2009 10:40 am

Nice write up matey! Very good read!!!

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Re: How-to: Cheap brake upgrade

Post by Shooter » Wed Jan 07, 2009 4:03 pm

A big big big thank you for this, that'a exactly what i was looking for.
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Re: How-to: Cheap brake upgrade

Post by Incompatible » Wed Jan 07, 2009 4:29 pm

Nice write up....plenty of the good technical "stuff" .
Last edited by Incompatible on Wed Jan 07, 2009 7:15 pm, edited 1 time in total.
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Re: How-to: Cheap brake upgrade

Post by WaZZZZman » Wed Jan 07, 2009 5:24 pm

Quote The 2.5i (as well as the Euro version 2.0i and 2.2i) have 286mm vented in the front and 280mm solid in the rear

I have 2004 Z4 2.5i and the front brakes do not appear to be vented at all. I wonder if they were changed to vented on later years? :(

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Re: How-to: Cheap brake upgrade

Post by ZetaTre » Wed Jan 07, 2009 6:33 pm

WaZZZZman wrote:Quote The 2.5i (as well as the Euro version 2.0i and 2.2i) have 286mm vented in the front and 280mm solid in the rear

I have 2004 Z4 2.5i and the front brakes do not appear to be vented at all. I wonder if they were changed to vented on later years? :(
I would highly doubt it... Just double and triple check. And just to be sure we're talking the same thing, "vented" means there's a space between the front and rear braking surfaced where air can go in and cool down the rotor. Here's how the profile looks like:

Image

And btw, here's how 300mm compare to 286mm (in my case the Z3 had 286mm solid); the 300mm are Brembo slotted

Image

And here's how the front wheel look like with (16" rims)

BEFORE: 286mm
Image

AFTER: 300mm
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2003 Z4 2.5i
2004 X3 3.0i
2002 Ducati Monster S4

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Re: How-to: Cheap brake upgrade

Post by ZetaTre » Wed Jan 07, 2009 6:36 pm

I added a comment regarding the E46 323i...
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Re: How-to: Cheap brake upgrade

Post by ElegantSpoon » Wed Jan 07, 2009 7:13 pm

Some good info there! I have been thinking about this mod so thanx :D

Any idea how much the 3.0si parts would be from BMW to upgrade from a 2.2i?
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Re: How-to: Cheap brake upgrade

Post by ZetaTre » Wed Jan 07, 2009 7:58 pm

ElegantSpoon wrote:Some good info there! I have been thinking about this mod so thanx :D

Any idea how much the 3.0si parts would be from BMW to upgrade from a 2.2i?
All and all you're probably looking at north of $1,500 (excluded rotors and pads)... A full 3.0i front and back can probably be found for about $300-$350 from a junkyard (again excluding rotors and pads)... If you have $1,500 to spend on brakes, go with some non-floating & multi-pistons calipers (just be careful as you might need spacers to clear the rims)...

Personally I think there's no need to buy them new. The car I got mine from had the entire front side ripped off in a collision: the suspension was destroyed, but the calipers were perfectly fine...

If you wanna be picky, you can rebuild the caliper with new o-ring and seals, maybe even a new piston... But unless you get them off some 200K miles car, you're more then fine by just cleaning them...
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Re: How-to: Cheap brake upgrade

Post by ElegantSpoon » Wed Jan 07, 2009 8:24 pm

Yea I understand what your saying :)

I have searched ebay for Z4 brake parts but theres never any on there. Thats why I thought if its not too expensive I could get them new.
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Re: How-to: Cheap brake upgrade

Post by ZetaTre » Wed Jan 07, 2009 8:39 pm

ElegantSpoon wrote:Yea I understand what your saying :)

I have searched ebay for Z4 brake parts but theres never any on there. Thats why I thought if its not too expensive I could get them new.
I ment 3.0si not 3.0i in my hestimate... The 3.0i should be cheaper as in the front you only need the carriers which are about $150 a piece.

Since you brought up the subject I added a comment regarding where to source them
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Re: How-to: Cheap brake upgrade

Post by WaZZZZman » Thu Jan 08, 2009 1:10 am

ZetaTre wrote:
WaZZZZman wrote:Quote The 2.5i (as well as the Euro version 2.0i and 2.2i) have 286mm vented in the front and 280mm solid in the rear

I have 2004 Z4 2.5i and the front brakes do not appear to be vented at all. I wonder if they were changed to vented on later years? :(
I am sorry I was confused between vented and slotted. Mine are vented as well. Thanks :o

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Re: How-to: Cheap brake upgrade

Post by cj10jeeper » Thu Jan 08, 2009 4:32 pm

ElegantSpoon wrote:Yea I understand what your saying :)

I have searched ebay for Z4 brake parts but theres never any on there. Thats why I thought if its not too expensive I could get them new.
Well you might want to search under other models that use what you need... try searching '330 caliper' or similar. You can see remanufactured LHS for £45 as an example.

I spent 10 minutes on Ebay and 2 phone calls this morning and have a pair of 330 calipers and carriers in the post to me. Total price is £120 inc. P&P all tested and warranted

Need to think about rotors sometime.

Perhaps I'll have a set of 3.01 calipers and carriers to trade away if anyone needs them.
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Re: How-to: Cheap brake upgrade

Post by ElegantSpoon » Thu Jan 08, 2009 7:15 pm

I might be interested in those cj if you do sell them drop me a PM :)
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