[tylerhart_21]

Looking online and doing some research, I have found out that the e9x 335i uses the same piston as the e9x 328i (57mm). But they use a different rotor and pad size. In addition the e9x m3 uses a 60 mm piston (Key note). On the e60 brake caliper (any non-m) they use a 60 mm piston and a 30 mm (pad I believe). The numbers on the caliper are 60/30/X. The bigger piston is within the 3.17 mm limit that is suggested and is based on the Alpinas where they give the b3 the same calipers as the 5 series. Plus the difference you would be getting is the braking/clamping force. My question is would doing down the e60 brake caliper route would be the best?

[TGTIW]

It's all about a balance of the specs involved and deciding what gives you the best results. So yeah, the 328 and 335 piston is the same size, with the 335 pad being slightly larger and the rotor being larger in diameter and width, which gives you better braking leverage and heat dissipation, but of course more weight.
The e60 calipers have a larger piston, which will give you a greater clamping force but a slightly softer pedal (enough to be noticeable, I don't know) and you get the same benefits and negatives as the 335 rotors.
Another option to consider and the one I went with. 330i rotors and caliper bracket. You can use your 328 caliper and pads, and the 330i rotor is 330x24

So going with the 335 or e60 option, is the additional braking performance worth the weight? I'm inclined to say no, only because I feel the 335 and e60 calipers are oversized for the pistons and pads they carry.

[neilvan]

Honestly yes, E60 V8 and 535(rwd) had the same 348mm dia and 30mm rotor width. Just the piston goes from 57mm to 60mm. As long as the slider bolts are in the same location I don't see why it wouldn't work.

I'm convinced the E90 M3 and the E60 V8 have the same caliper just different stamping

[wrevilo]

Another option is the fixed F3x calipers that have options for 340mm or 370mm rotors. I'm sure the combination of piston sizes and area in comparison to the Exx generation have been calculated!

[tylerhart_21]

wrevilo I will agree with your that the F3x caliper would be better since it has more pistons and it’s allows the pressure to be spread out on the rotor more. The only downside would be playing double for just the calipers but it does look better on the car.

[mattanderson]

Interesting idea. What rotors would you run?

I run the 335i calipers on my 328i, and I get zero fade after a 20min track session (on track pads), so I feel like the 335i brakes are plenty. The F3x brakes look cool, but it's paying a lot more for mostly looks, IMHO.

If the E60's bolt right up, though, they appear to be just as cheap as the 335i calipers (I paid ~$100 on eBay for mine).

[tylerhart_21]

Originally Posted by mattanderson

Interesting idea. What rotors would you run?

I run the 335i calipers on my 328i, and I get zero fade after a 20min track session (on track pads), so I feel like the 335i brakes are plenty. The F3x brakes look cool, but it's paying a lot more for mostly looks, IMHO.

If the E60's bolt right up, though, they appear to be just as cheap as the 335i calipers (I paid ~$100 on eBay for mine).

It looks like 348 mm are the standard size for the brake calipers, but from what I was reading the 535d has the same brake pad as the m5 but that could have been a old rumor. The bigger the rotor would be better so it can spread the heat, but that would also mean more weight. Unless you go with a weight light rotor which would be more expensive compared to Zimmerman or OE manufacturers.

[tylerhart_21]

Another option is euro 535d brake calipers, they are bigger but they have two pistons instead of just one big one.

[mattanderson]

So same size as 335i? 348 x 30mm?

Can confirm that they are a bit heavier than stock 328i rotors, but it's worth it for me.

[tylerhart_21]

Yeah the same size as the 335i ones but rumor has it, the z4 35i rotors are alittle lighter since they have aluminum hats.

[Brandoch]

What's the goal here? Are you experiencing brake fade on multiple hard stops?

[tylerhart_21]

Originally Posted by Brandoch

What's the goal here? Are you experiencing brake fade on multiple hard stops?

The goal would be better brakes for street/mountain driving. Building the car in the style of Alpinas. Plus I want to make sure the brakes feel solid as well when it comes to wet/heavy fog. I had one time where the brake pedal felt more mushy than usual when driving in heavy fog.

[mattanderson]

Thinking about this some more, the bigger caliper piston would apply more brake pressure for the same pedal travel, effectively increasing front brake bias.

If you're planning on retaining 328i rear brakes (like I am), I don't think you'd want that additional bias. The 335i fronts are more than sufficient for the 328i's power and weight.

[Leucosticte]

Originally Posted by tylerhart_21

Another option is euro 535d brake calipers, they are bigger but they have two pistons instead of just one big one.

Do you have an example? Looked on realoem and couldn't find those 2 piston ones.

[tylerhart_21]

Originally Posted by mattanderson

Thinking about this some more, the bigger caliper piston would apply more brake pressure for the same pedal travel, effectively increasing front brake bias.

If you're planning on retaining 328i rear brakes (like I am), I don't think you'd want that additional bias. The 335i fronts are more than sufficient for the 328i's power and weight.

Question would be could this be offset by changing the brake master cylinder. When I do the brake upgrade I am going to be an overhaul for the whole system. Such as m3 brake master cylinder, SS brake lines, upgraded brake calipers/disc.

[tylerhart_21]

Here is a link to the caliper:
https://www.ebay.co.uk/itm/256667881...3ABFBMurnVvdpk
As well here are some pictures of it as well: