335i Fronts + 328i Rear Calipers on my 128i

[DarthBeardy]

Not a guide or walkthrough really, just follow a standard Caliper/Rotor guide, swapping in the front rotor/caliper from a 335i, and the rear caliper from a 328i. This enables more stopping power, without sacrificing our e-brake on the 128i. Since I needed new pads/rotors anyway, my net cost was around $200 for the upgrade.

Anyways, while not perfect (The G2 reacted oddly with the front calipers, seeming to be "repelled" from sections), but you can't see the imperfections when mounted, so I am satisfied with how they turned out.


Before/After:



The goods:





Small Walkthrough:


















Some notes:

• Gotta have 18" wheels
• Front Calipers on ebay are ~$40/each, rears are ~$25.
• No need for steel lines, especially for a DD. These are Kevlar reinforced.
• Front bleed screw is now significantly larger on the front 335i calipers.
• I noticed a more "refined" pedal. Probably by using DD style pads vs race style, the initial bite is much more refined, and I feel I have more control over the amount of braking.
• You 100% can lock up all four corners with DTC off, I don't recommend it.
• You can use rotors from a Z4 35is which are two piece with an aluminum hat to save ~2lbs each. I ordered directly through the dealer, with the Z4 part numbers, and I got single piece steelies. Not super upset, it is what it is.

Not sure why I can't resize the images. So apologies on that.

[swagon]

Nice job, dude. I like the blue color.

[DarthBeardy]

Originally Posted by swagon

Nice job, dude. I like the blue color.

Thanks!

Just picked up some VMR’s and some PSS’s! Very happy.

[Eau_Rouge111]

Originally Posted by DarthBeardy

Thanks!

Just picked up some VMR’s and some PSS’s! Very happy.

Looks good!! I just finished installing and bedding in a set of 4 piston F30 calipers with the 340mm disks on my 128i...have the 328i rear calipers but will mount those on when they have been properly cleaned. I've done a few hard stops...100km to 0 and it feels normal...the bias is still normal.

[andawheee]

I have a 128i as well and wow, you've got me officially inspired My rotors need to be changed anyway so why not get some paint ready for the calipers too? Question, as a noob, why can't you paint every part of the pieces? Will it reduce/alter performance?

[BikeNHV]

Great work!
This conversion is definitely interesting to me, but I do want to stay with 17" wheels.

Searching the E90 forums, it seems that SOME 17s will fit over the 335i front calipers (335i base non-sport coupe came with 17s) but it's not always easy to determine from the wheel specs.

I guess I could find someone with a 335i and try test fitting a front wheel.

[gjm120]

Originally Posted by BikeNHV

Great work!
This conversion is definitely interesting to me, but I do want to stay with 17" wheels.

Searching the E90 forums, it seems that SOME 17s will fit over the 335i front calipers (335i base non-sport coupe came with 17s) but it's not always easy to determine from the wheel specs.

I guess I could find someone with a 335i and try test fitting a front wheel.

Most won't work because the 1er offsets are so unique.

[chris82]

Great write up, very good info here.

Originally Posted by BikeNHV

Great work!
This conversion is definitely interesting to me, but I do want to stay with 17" wheels.

Searching the E90 forums, it seems that SOME 17s will fit over the 335i front calipers (335i base non-sport coupe came with 17s) but it's not always easy to determine from the wheel specs.

I guess I could find someone with a 335i and try test fitting a front wheel.

Apex ARC8 17" should fit over them no problem as they can clear a 355mm Stoptech BBK (Apex says so in the thread I'm linking). I was just browsing this thread as I'm also upgrading to the 335i front caliper/rear 328i calipers and plan to use my current ARC8 17x8" wheels.

https://www.e90post.com/forums/showthread.php?t=651864

Question though, the 328i caliper bolts right up to the stock 128i rear parts right? No new rotors needed? I see for the pads I use, DTC70, they're the same between 128i/328i, are rotors the same though? Appreciate it!

[SKI-R]

Originally Posted by chris82

Question though, the 328i caliper bolts right up to the stock 128i rear parts right? No new rotors needed? I see for the pads I use, DTC70, they're the same between 128i/328i, are rotors the same though? Appreciate it!

Correct. Simply a larger caliper piston.

[amg6975]

Originally Posted by chris82

Great write up, very good info here.



Apex ARC8 17" should fit over them no problem as they can clear a 355mm Stoptech BBK (Apex says so in the thread I'm linking). I was just browsing this thread as I'm also upgrading to the 335i front caliper/rear 328i calipers and plan to use my current ARC8 17x8" wheels.

It's not no problem they are very, very close on a 9" wheel. Not sure about the 8". Barrel should still juuuust fit, but I'm not sure about the spokes.

[chris82]

Originally Posted by amg6975

It's not no problem they are very, very close on a 9" wheel. Not sure about the 8". Barrel should still juuuust fit, but I'm not sure about the spokes.

Made a typo there, I plan to use 17x8.5", not 17x8". According to Apex, they SHOULD fit no problem and I certainly hope that's the case. Their fitment guide says absolutely nothing about clearance issues with stock brakes on the E9x (and those are usually up to date) and the thread I listed says the 17x9 will clear the stock and even larger 355mm Stoptech kit. Also, one model of 335i came with 17s no?

[amg6975]

Originally Posted by chris82

Made a typo there, I plan to use 17x8.5", not 17x8". According to Apex, they SHOULD fit no problem and I certainly hope that's the case. Their fitment guide says absolutely nothing about clearance issues with stock brakes on the E9x (and those are usually up to date) and the thread I listed says the 17x9 will clear the stock and even larger 355mm Stoptech kit. Also, one model of 335i came with 17s no?

All I know is I had 17x9 et42 ARC8s on my 135 that had the 335 brakes and it was super close. I would be incredibly surprised if they fit under any factory 17s.

[chris82]

Originally Posted by amg6975

All I know is I had 17x9 et42 ARC8s on my 135 that had the 335 brakes and it was super close. I would be incredibly surprised if they fit under any factory 17s.

Oh didn't know you were speaking from experience. When did you buy those ARC8s? I think they might have gone through a redesign but I'm not 100%. Im really hoping they fit over mine now..

[SKI-R]

Fit my square setup 17x9 Flow One Race Spec F2s without issue (10mm spacer up front IIRC)….can’t recall if I tested my K1s, but my 17 inch winters also fit without issue = don’t panic.

[chris82]

Just mounted up my 17x8.5 et40 Apex arc8 and can confirm they fit with no issue at all

[bender128]

Any concerns for brake bias?

[j128id]

Any specific model year I should look for when sourcing 335 and 328 calipers? What should I look for included with the calipers?

[Blau]

Originally Posted by j128id

Any specific model year I should look for when sourcing 335 and 328 calipers? What should I look for included with the calipers?

https://www.1addicts.com/forums/show....php?t=1132152

I'm in the research process of this as well. My hangup is the various reports of a longer brake pedal. I don't want to do the master cylinder and may pass if that's a must. I think that stock parts plus great pads might be fine for 1-3 track days a year.

If anyone else can chime in with their brake pedal experience I'd be thankful.

and j128id I don't mean to be a hater, but you've got to use the search function of this sub. It's pretty comprehensive.

[SKI-R]

My experience has been a longer brake pedal feel with the combined front & rear caliper swap and everything else remaining stock (other than Motul fluid).

Spring will bring stainless line (x 6) install and subsequent Castrol fluid flush - doubt that will change anything to be honest, but my lines are now 15 years old and one can always hope!

[spidertri]

Originally Posted by WeShallCallHerBlau

https://www.1addicts.com/forums/show....php?t=1132152

I'm in the research process of this as well. My hangup is the various reports of a longer brake pedal. I don't want to do the master cylinder and may pass if that's a must. I think that stock parts plus great pads might be fine for 1-3 track days a year.

If anyone else can chime in with their brake pedal experience I'd be thankful.

If you're only doing 1-3 track days each year, I think you'll be fine with the stock brake calipers. Like you said, get track pads and better fluid and you'll have a blast out there. I will say that the stock brakes with the non-m sport bumper get very little cooling air. They can definitely get overheated as you do more track days and work your way up into the faster run groups. Trimming the backing plates and adding scoops/ducts to direct air at the back of the rotor helps a lot in keeping the stock brakes happy.

The simple fact is that going to any of the larger caliper options, 135i, 335i, or F30 brembo, means that you have more brake piston volume than you will with the single 54mm piston in the stock 128i caliper. That means you have to push the pedal further to get the larger caliper's piston(s) to extend the same amount.

I have the bigger calipers on my car and I did a lot of track days with them and the stock 128i MC. It was fine, the car stopped and had no issues.

I did have a longer pedal and ultimately installed the 135i MC, that has been one of the best changes I've made. It got rid of pedal travel and made it much easier to heel-toe since the brake pedal doesn't drop as far under heavy braking.

[Blau]

Originally Posted by spidertri

If you're only doing 1-3 track days each year, I think you'll be fine with the stock brake calipers. Like you said, get track pads and better fluid and you'll have a blast out there. I will say that the stock brakes with the non-m sport bumper get very little cooling air. They can definitely get overheated as you do more track days and work your way up into the faster run groups. Trimming the backing plates and adding scoops/ducts to direct air at the back of the rotor helps a lot in keeping the stock brakes happy.

The simple fact is that going to any of the larger caliper options, 135i, 335i, or F30 brembo, means that you have more brake piston volume than you will with the single 54mm piston in the stock 128i caliper. That means you have to push the pedal further to get the larger caliper's piston(s) to extend the same amount.

I have the bigger calipers on my car and I did a lot of track days with them and the stock 128i MC. It was fine, the car stopped and had no issues.

I did have a longer pedal and ultimately installed the 135i MC, that has been one of the best changes I've made. It got rid of pedal travel and made it much easier to heel-toe since the brake pedal doesn't drop as far under heavy braking.

Thanks for the input. I think I'm going to opt for the m-sport bumper or 1M clone bumper this summer when I do the oil cooler install, so that should help with cooling. If I like track days I'll do the upgraded brakes job, with the larger MC.

[Z3SpdDmn]

Originally Posted by bender128

Any concerns for brake bias?

Yes. It shifts forward.

128i vs 128i Performance vs 335i Brake Bias Calculations

I've swapped a 1M/M3 Master Cylinder and Booster and the pedal feel is AWESOME. The shorter travel is restored, placing the pedal appropriately relative to the accelerator pedal for heel-toe. It's essentially a 1M system now, with a slight difference in rear calipers that's not perceptible to me.
Note that I got the MC and booster from salvage because I wanted to stick with OEM, but new ones were way more expensive than they should be. Well, the MC ended up being gunked up and I had to get a new one anyway. I ended up getting an aftermarket one from RockAuto. I had to pay for the labot to swap it twice, unfortunately, but I'm extremely happy with the results.

So, here's the summary of my swap:
335i front calipers w/ Z4 35is floating rotors, no backing plates. Custom brake cooling deflectors mounted to the control arms.
328i rear calipers w/ stock rotors
1M Master Cylinder and booster
Performance Brake tune coded
Hawk HPS 5.0 pads for street, Ferodo DS2500 pads for track (just what I happened to have on hand)

My Sparco 17x7.5" wheels fit over the brakes, barely, but stock 17"s do not. I'm running on 225/45/17 Michelin PS4S and the car now keeps up with me (pro driver) for continuous lapping, which was my goal for this system. The fact that the brakes feel awesome on the street is a good bonus, because that's where the car spends most of its time. Now that I have Ohlins R&T suspension on it, I'm looking forward to tracking it again. If I'm really enjoying it, I might get some sticker rubber and higher temp pads for it.