[TechieCarGuy]

I realize that this has been addressed over the years, but most of the DIY’s and related post are older and any pictures have been lost to the PhotoBucket Goonies, so I wanted to ask yet again another Big Brake Kit questions, but this time specific to the US Spec E91 328 Xdrive Touring, or 328XiT as it has been referred.

I have read agnosia, that the ‘FRONT’ BMW Performance (135 6-piston and rotors) and the F30 M Brakes are a fairly easy swap. As are the larger brakes off of the 335 sedan, however it gets a little confusing as it relates to the rear installation options and maintaining the use of the parking brake. I recall reading on more than one forum, that the 328XiT has a different rear spindle assembly than the regular or Xdrive sedan or RWD wagon. While many have commented on this, I have not found any details about this or anyone that has made a conversion on a 328XiT using any of these options.

I am looking at doing either one of the OEM BB options, or the 335 upgrade and would like to confirm before I buy parts to learn which, if any is a direct fit in the rear. I am aware of the various modifications needed on the 335 Xdrive to get the F30 rears and the 135 brakes to work, but recall hearing the Xdrive Wagons are an exception to the rule and would like to find out which option would be the most straight forward, with least amount of modification. I can confirm that at least the rear parking brake shoe and ring on the328xiT, the e90 335 and the F30 335 are the same 185mm part number, but am not certain this is the problem

I drive a highly modified N54 135 on a daily basis and love the 6-piston brakes on it, and have an extra set of front calipers for it and since I am contemplating an ESS Supercharger on my e91, would love to go that route, but am also conscious that I could get equal or better performance from the 335 upgrade. As of May 2018, the options for Performance parts for this 8 plus year old platform is either going up in price, or becoming harder to find in kit forms, i.e. BMW Performance, or ECS build F30 kits, so I am trying to get a definitive answer so I can start building up this car and know what is needed. My goal is to use OEM parts when at all possible.

[feuer]

Since you have extra 135i front calipers used them but upgrade the pistons first. e91 have 185mm parking brake so you can mount 135i rear calipers with 335i rear rotors and 1-2mm washers between caliper and spindle.

[TechieCarGuy]

What was the deal about the rear of the Xdrive wagons being different? Did I imagine that? or is that what will facilitate using the 335 rotors?

[feuer]

Don't know if xdrive wagons are any different from RWD wagons.

[ChazCulver]

Any updates on what you went with?

I thought I found that the BMW Performance Front BBK (135i Stock Front Brakes?) was a Direct Fit for E91 X Drive.

Also the 135i Rear Brakes were a Direct Swap.

Maybe I'm Mistaken?

[TechieCarGuy]

Originally Posted by ChazCulver

Any updates on what you went with?

I thought I found that the BMW Performance Front BBK (135i Stock Front Brakes?) was a Direct Fit for E91 X Drive.

Also the 135i Rear Brakes were a Direct Swap.

Maybe I'm Mistaken?

Its funny you decided revive this thread when you did, I had forgotten I started it and have only recently revisited this upgrade.

I have not found any thing other than hearsay that the rears from a 135 will work on an e91 xdrive without modifications and will allow for rear parking brake functionality. The biggest challenge I think is the rotors, which from what I have found the stock 328xi E91 are 300x20, with a 185mm hat diameter for the parking brake to work in. The 135 rears are 324x22, hat diamter I am unsure about.

From what I have found the 300x20 are a little small for the 135 rear caliper and will create problems in that the pads do not fit complete on to the rotor and hang off a little. Some feel this isn't a big deal, but I want OEM fitment so that is a no go.

Others efforts have show a European part from a 7-series 6cylinder (730/735) which is a car that we do not have in the U.S. The rear rotor on the 730i is a 324x20 rotor. But I can not confirm if doing this will give you the parking brake function or not.

That is as far as I have gotten. I am selling my 135 so have held off buying any additional components until money changes hands from that deal, once I finalize the sale of my 135 it'll be between the BBK upgrade or new wheels for my E91 wagon. Decisions, decisions....

If anyone has any additional information please share. I think we have established that the fronts are fairly simple, minus a little grinding of the caliper bracket and cutting of the dust shield, but the rears seem to still be an issue. So few people have e91's that want to do this conversion, I suspect that is why detailed confirmation is hard to comeby.

[ChazCulver]

Does the Performance BBK Come with a dust shield that does not require any modification?

[TechieCarGuy]

I believe so, yes.

[eljay]

I'm interested in this as well as I would like to install 135i brakes at some point on my E91 328xiT.

[tlow98]

I believe the only difference in the rear end on the x-drive is the lower diff ratio of 3.91 (?). I forget the exact number, but it’s different than rwd versions

[TechieCarGuy]

There have been several threads that eluded to the rear on the xdrive wagons being more of a direct bolt on for the 135 brake upgrade as far as getting the emergency brake working. That functionality is key for any such upgrade for me.

However, that is part of my problem, I can not confirm this and comments in other forms such as " your golden if you have an Xdrive wagon" do little to explain the difference and whether or not it is that simple. I've read that its more about the rear rotor assembly than anything else but that is what I am trying to find out.

[zstreet86]

If you want to see what's different between models, go to realoem.com and compare configurations.

[ChazCulver]

Or you could put an end to it all, and just try it out! =) We'll all thank for you the useful knowledge! and It would give me the push to buy the brakes now =)

[tlow98]

Originally Posted by Quart

There have been several threads that eluded to the rear on the xdrive wagons being more of a direct bolt on for the 135 brake upgrade as far as getting the emergency brake working. That functionality is key for any such upgrade for me.

However, that is part of my problem, I can not confirm this and comments in other forms such as " your golden if you have an Xdrive wagon" do little to explain the difference and whether or not it is that simple. I've read that its more about the rear rotor assembly than anything else but that is what I am trying to find out.

You’re Golden if you have a RWD wagon, that’s for sure. It has to do with the parking brake sizing - they’re the same between the 335i and the 328i RWD wagon. The reason is mass and reserve capacity in the brakes - it takes more force to slow down something either heavy or fast. The wagon is heavy so it has the same size parking brake assembly as the fast and relatively heavy 335i. I’d be shocked if the Xdrive wagon had a smaller parking brake as its even heavier yet...

There are already several 335i brake upgrade threads on here for the RWD wagon. It’s an easy conversion. Buy 335i rotors, install, profit.

Check realoem.com. If you have the same rear rotors as the rwd wagon then your good to go for a 335i brake upgrade.

[E91 M Sport]

When I get my pool/backyard completed I'll pursue this company. Best price I've seen hands down for reputable calipers.

http://store.revolutionbrake.com/14-0142.html

[TechieCarGuy]

Originally Posted by E91 M Sport

When I get my pool/backyard completed I'll pursue this company. Best price I've seen hands down for reputable calipers.

http://store.revolutionbrake.com/14-0142.html

Interesting, can't say I've seen a Wilwood option for our cars come up before. I am unaware of a difference in the front from '06 to 2011/12 which is what I have and it appears you have from your signature. That would be an interesting thing to learn as well. Price is much better than I have seen, the F30 option when it was still available from ECS was $2300 for front so this is promising.

[TechieCarGuy]

OK, I am still trying to work through this and after reading and re-reading all the post am hoping I can rekindle the discussion and get some of the folks who have done this mod to offer their input. I am specifically looking at the rear brake conversion on the LCI 328xi Wagon (e91).

I have sourced all the calipers and am confident the front will fit with minor modifications, but it is the rear brakes I am confused about... this thread indicates a solution in part #34216795755 and speculates it will fit a 328xi. But they individual who claims this did the conversion on a 325xi, which has different original rear brakes and the same thread goes on to incorrectly claim that the 325, 330 and 328 all have same sized rear brakes as the 328xi, a 300x20 rotor. However, my US spec 328xi according to realoem has a 312x24.

The suggested part that is said to be a rear performance rotor for a 335 is a 324x22 rotor. A number of people speculate this should fit that, but the only evidence I can find is this being done on a straight rwd 328i and the brake pad not reaching the edge of the rotor, and on a 325xi in europe which has different oem rotors and parts to the US spec 328xi.

In this same thread there is a suggested e65 eurospec 7series rotor, but again it is unclear as to whether it worked on the wagon. I'm at point of buying my rotors and would like to do it once, so am obviously looking to get some confirmation for which rotors work on a US spec, 328ix wagon.

The 135 rear rotor from factory is a 324x22 and has part number of 34216795754 for the performance rotor, has the same sized 185mm parking brake as the 34216795755 but having had a 135 I know that the rotor hat is to tall for the e91, so am left to assume the*5755 part number being one number off may be correct, but am looking for some validation.

[K9Leader]

Quart:

I'm glad I found this thread and hope to learn from your experience. I have a 2010 E91 X-drive that I would like to upgrade the brakes, and, as you are, I want to keep it as close to OEM parts as possible and keep the parking brake. I had the chance to do a BMW track day at Pocono last month and drove a couple of laps in an M550 and, Wow!, do those brakes make a difference in what you can do!

Had been looking to do it immediately but just had to drop a lot of coin on a transmission for my '99 Corvette, so brakes for the BMW will probably be a "next Summer" project.

So, are you going with the 135 calipers/rotors up front or the 335s? You mention minor modifications - what are they and how minor?

And, do post up when there are any developments or progress on the project.

K9Leader

[TechieCarGuy]

As shown, I've got a set of BMW Performance brake calipers, which are the same as the 135 brakes but Phoenix yellow instead of Graphite grey metallic. I'm contemplating having them powder coated another color since I normally go with more subtle colors. I went as far to get a quote of $90 per caliper to chemically remove the current paint and redo it in the color of my choice, however this guy can't do the painted on logo so I'd have to do stickers which I am not sure I want to do. I think it would look cheap.

I have the 135 Performance front rotors and as I've stated its the rear I am uncertain about, but will probably try the BMW Performance ones mentioned before (34216795755).

When I say modifications, I'm referring to the front caliper and how it mounts. I believe you have to remove a portion of the knuckle on the bracket that connects the caliper to the car and you have to remove a wedge out of the thin aluminum dust shield as well. But that seems to be the only thing that needs to be done to get the front to work.

[tlow98]

At this point you’ll only be buying a couple different rotors. Just buy them and return the ones that don’t work. You’ll only be out shopping right?

Appreciate the info you’re unearthing!

[ChazCulver]

I had read on this forum multiple times that ALL E91 have the same rear parking brake as the 335.

There for, all 335 Brakes will fit on E91 with zero modification.

There for, there should be no issue installing a Performance BBK thats synonymous with 335.

A simple search for 335 to 328 brake upgrade will yield the results you're looking for i believe.

[chuckn0rr1s]

Originally Posted by Quart

however this guy can't do the painted on logo so I'd have to do stickers which I am not sure I want to do. I think it would look cheap.

When I worked at a performance shop my boss had Lamborghini calipers painted to match the color of the car. Our painter added the "Lamborghini" stickers before adding the clear coat then added the clear coat after adding the decals. It actually made it look really nice! logos looked like they were somehow embossed onto the caliper. We never had issues with decals coming off that I know of.