[LMB335IS]

Originally Posted by feuer

Have ECS send you new O-ring for the cylinder. Goes between the cylinder and the vaccum booster. Is like $2 and not worth skiping on it only to find out that the old one leaks.

Good idea. Will do.

[LMB335IS]

Originally Posted by LMB335IS

Good idea. Will do.

Getting there

[Cloud9blue]

Originally Posted by LMB335IS

Getting there

I am not sure that's a good idea. Removing that much material from critical load bearing part of the caliper is something I wouldn't do personally. Machining the hub is a much safer choice since that part is made of steel not aluminum (a much weaker material relatively).

[LMB335IS]

Originally Posted by Cloud9blue

I am not sure that's a good idea. Removing that much material from critical load bearing part of the caliper is something I wouldn't do personally. Machining the hub is a much safer choice since that part is made of steel not aluminum (a much weaker material relatively).

I'll be OK. There's others is this thread that have been using calipers machined like this for over two years and with multiple tracks sessions thrown at them with no ill effects so far. That's not to say that you don't have a point, I get it. It's a calculated risk. At least it's the rears so the stress is not nearly as high as the fronts.

[techwhiz]

Looks like the machine job done on mine.
The calipers are forged. That bolt insert is very, very hard.

I didn't worry about it.

[feuer]

Originally Posted by Cloud9blue

I am not sure that's a good idea. Removing that much material from critical load bearing part of the caliper is something I wouldn't do personally. Machining the hub is a much safer choice since that part is made of steel not aluminum (a much weaker material relatively).

Originally Posted by LMB335IS

I'll be OK. There's others is this thread that have been using calipers machined like this for over two years and with multiple tracks sessions thrown at them with no ill effects so far. That's not to say that you don't have a point, I get it. It's a calculated risk. At least it's the rears so the stress is not nearly as high as the fronts.

Very good machining! Look great.
I didn't not have to mill them between the tubs as you did.
Safety wise is OK!
There is 12mm left and that is what you see in most adapters for calipers applications.
Granted, different grade aluminum but still it should hold up well.

[LMB335IS]

Originally Posted by feuer

Very good machining! Look great.
I didn't not have to mill them between the tubs as you did.
Safety wise is OK!
There is 12mm left and that is what you see in most adapters for calipers applications.
Granted, different grade aluminum but still it should hold up well.

The guys that did it designed a fixture to hold the caliper. They're going to start offering this service to locals or maybe even others that want to ship theirs in for machining. They do outstanding fabrication and custom work.

[wshgrntd]

Im going for the same look... on my pre-lci 335i sedan....

[DirtKurt]

Finished this conversion about a month ago, To center this caliper on the rotor you need to take off 7mm. There was no way that was happening on the caliper alone imo. I machined the knuckle 3.5 and the caliper 3.5 The knuckle mounting holes also have to be enlarged and moved outwards 1.5 mm or the rotor will hit the inside of the caliper.

[DirtKurt]

Just to clear up a lot of the gray area that surrounds this swap, This 12mm number that keeps popping up is not correct. If you mill the caliper to 12mm its is NOT centered on the rotor. It is just barely able to fit over and is very much off center. Basically one pad has a bunch of space and the other is dragging. 7mm is the exact number that the caliper needs to be moved inwards or the rotor has to be moved outwards.

[R99]

Is that 7mm measurement the same for pre-LCI & the LCI?

I know that LCI has a wider rear track, which part gives this?

[feuer]

Originally Posted by DirtKurt

Just to clear up a lot of the gray area that surrounds this swap, This 12mm number that keeps popping up is not correct. If you mill the caliper to 12mm its is NOT centered on the rotor. It is just barely able to fit over and is very much off center. Basically one pad has a bunch of space and the other is dragging. 7mm is the exact number that the caliper needs to be moved inwards or the rotor has to be moved outwards.

Just to clear up > 12mm is the thickness of the caliper mounting tab after is shaved 7 to 8mm I have stated this VERY CLEARLY!
It was done few years ago and many have followed suit. You have simply misread.

[feuer]

Originally Posted by R99

Is that 7mm measurement the same for pre-LCI & the LCI?

I know that LCI has a wider rear track, which part gives this?

Is the same pre LCI or LCI, no difference.

[DirtKurt]

Originally Posted by feuer

Just to clear up > 12mm is the thickness of the caliper mounting tab after is shaved 7 to 8mm I have stated this VERY CLEARLY!
It was done few years ago and many have followed suit. You have simply misread.

Actually no, it's not. Your so confident in your b******* you actually had me second-guessing myself

Didn't misread at all if you mill the mounting tabs down to 12 millimeters thickness you move the caliper inwards 5.5 millimeters. This leaves the caliper 1.5 millimeters off center. This just so happens to be the exact amount of space that a fresh pad has in between the rotor and caliper piston with the Piston fully compressed. And the number is 7mm. Not 7 or 8, you seem confused about that.. so yes do it this way and you end up with an inner pad that's dragging and a substantially compromised caliper.

[techwhiz]

Originally Posted by DirtKurt

Actually no, it's not. Your so confident in your b******* you actually had me second-guessing myself

Didn't misread at all if you mill the mounting tabs down to 12 millimeters thickness you move the caliper inwards 5.5 millimeters. This leaves the caliper 1.5 millimeters off center. This just so happens to be the exact amount of space that a fresh pad has in between the rotor and caliper piston with the Piston fully compressed. And the number is 7mm. Not 7 or 8, you seem confused about that.. so yes do it this way and you end up with an inner pad that's dragging and a substantially compromised caliper.

Can you tone it down a bit?
I have done the mod with 12 mm.
If you use stock rotors, there is not an issue because the stock rotors are thinner. On the other hand if you use the performance rotors, which I did, you will need to shave the pad by about 1-2 mm, which I did.

To not compromise the caliper, you don't go below 12mm which is a hair thinner than ½". If you shave the pads you are good to go.

Been there, done that!

[techwhiz]

Originally Posted by R99

Is that 7mm measurement the same for pre-LCI & the LCI?

I know that LCI has a wider rear track, which part gives this?

The track is wider for LCI and the mounting knuckle for LCI and pre-LCI cars is different.
So they move the caliper by changing the thickness of the mounting face on the knuckle and assorted parts. The caliper and rotor are the same on pre-LCI and LCI cars.

[DirtKurt]

Originally Posted by techwhiz

Can you tone it down a bit?
I have done the mod with 12 mm.
If you use stock rotors, there is not an issue because the stock rotors are thinner. On the other hand if you use the performance rotors, which I did, you will need to shave the pad by about 1-2 mm, which I did.

To not compromise the caliper, you don't go below 12mm which is a hair thinner than ½". If you shave the pads you are good to go.

Been there, done that!

Sick of the misinformation floating around this thread. Apparently I'm the only one who has taken the time to measure the components and get accurate dimensions. I started the swap with the information contained in this thread and quickly realized it was wrong. If people are going to do this conversion they should at least have good information to go off of.

Speaking of misinformation milling the caliper to 12mm does not leave 12mm of material connecting the tab to the caliper it's more like 6.5mm. I'll get an exact number tommorow

[feuer]

Originally Posted by DirtKurt

Sick of the misinformation floating around this thread. Apparently I'm the only one who has taken the time to measure the components and get accurate dimensions. I started the swap with the information contained in this thread and quickly realized it was wrong. If people are going to do this conversion they should at least have good information to go off of.

Speaking of misinformation milling the caliper to 12mm does not leave 12mm of material connecting the tab to the caliper it's more like 6.5mm. I'll get an exact number tommorow

True, when I did this mod few years ago I wasn't thinking of fellow e9x guys who would like to follow suit. I pretty much did it on the fly over night.

I measured the caliper only so I would do both equally and no other purpose. The caliper was milled to 12mm primarily because that was the thickness of the existing caliper carrier.

How accurate my measurements were? It depends on how accurate the tool was. Nevertheless, it worked! Additionally I didn't had to mill/shave the pad because of pad dragging.

I'm going on my 3rd summer on the setup and 2nd rear pads with zero issue. I track it too.

Everybody is modding on their own risk. What work for one doesn't necessary work for somebody else.

You stated your discovery and we value that. I personally give you reputation mark just the other day.

Now, instead of being respectful that somebody was brave enough to try it and encourage others to do it just like in your case (you read hear how I went about it and give it a go) you sound like you have found the correct way how to make water boil or invented the wheel again.

You did not.

[DirtKurt]

Originally Posted by feuer

Just to clear up > 12mm is the thickness of the caliper mounting tab after is shaved 7 to 8mm I have stated this VERY CLEARLY!
It was done few years ago and many have followed suit. You have simply misread.

It took this post as an insult, if that wasn't how it was intended then I apologize for the hostile response. Not sure how the laughing smiley was supposed to be taken.

I 100% agree this is a custom mod and there is know right way to do it, and anyone who takes it on does so at there own peril.

My one and only goal here is to provide accurate dimensions and a understanding of what each approach will give you as a result.

One that note I will sum it up.

- caliper machining to 12mm = fits over the rotor, caliper offset 1.5mm on rotor. Easiest method by a long shot. Inner pad may drag on rotor, caliper mounting tabs are the thinnest.

- knuckle and caliper machining 3.5 mm each. Caliper centered on rotor more material left on the caliper mounts. Most labor intensive, still compromises caliper mounts

- 135 hub swap, machine 3mm off of 135 hub and space out park brake assembly 7mm. No caliper machining. Increase track width 7mm per side

ALL of the above methods require offset boring of the knuckle mounting tabs to fit the larger hardware and move the caliper out 1.5mm.

That's all I got

[techwhiz]

No matter how you do it, it's a custom job.
If you are already running wide wheels and tires, you can't do the hub.
Another 7mm toward the fender on my car worn't work. Also when you do the hub mod, you leave part of the parking brake shoes exposed. They no longer ride completely inside the hub. Not a big deal but each method to make this work in the rear has issues.

If you don't go with performance rotors in the rear you have a lot more room for error.
With the performance rotors 1mm off and your pads are dragging.

[wshgrntd]

anyone thought of replacing the knuckle with the f30 knuckle? Or is it completely different?

[cvincent3]

I'm going to be doing this brake upgrade in the next few weeks.

Going for the M4 brakes, fronts are bolt on as we know.

With the rear, what discs am I going to need with the M4 calipers?

325d E92 LCI.