[tlow98]

Originally Posted by Volasko

Super tempted to take a shot at these. I can't stand how much my "geomet" coated rotters from ECS tuning have rusted.

Yeah, ECS, has great pictures, but it doesn't always mean they have great stuff. At least, that's what I've found out.

I've always used the Centric painted 'premium' rotors. They're super reasonable and have yet to rust on me - even in the salty winters of Chicago. I don't take it easy on them at the track and they work well.

Oh, and RockAuto is great. They carry most of the OE/OEM brands and their prices are the best around. Trick is to dig deep and choose the correct brand/part number you're after.

[AtlasM]

So far the only cheap 2-piece rotors I've been able to confirm are the Z4 28i/35i 330x24 mm size. They are:

DuraGo BR901054
Pronto 30422-05264501
Pilenga W0133-1935021

The US-market cars that use this size but come with 1-piece rotors are the E9x 330i/330xi and E84 X1 28i. There are tons of EU-spec cars that use this size, but most other US-spec E9x/E8x models use the smaller 312x24 mm rotors.

As for Z4 35is 348x30 mm 2-piece rotors that would fit the 335i/xi, I've not yet been able to find any part numbers listed in the Pronto catalog, which is just pulling from showmetheparts.com. The BMW part number is 34116782593 and the best price I've found on them is $171.99 each at eEuroparts.

[AtlasM]

Originally Posted by tlow98

Oh, and RockAuto is great. They carry most of the OE/OEM brands and their prices are the best around. Trick is to dig deep and choose the correct brand/part number you're after.

I'm definitely a RockAuto fan. The only thing that bugs me about them is they're right here in Madison, literally 3 miles from my house, but they don't do local pickup. I think they pull from multiple warehouses so probably wouldn't be possible. Doesn't stop me from feeling a little annoyed to pay 20 bucks for shipping something heavy like rotors when I drive past their HQ all the time.

[tlow98]

Originally Posted by AtlasM

I'm definitely a RockAuto fan. The only thing that bugs me about them is they're right here in Madison, literally 3 miles from my house, but they don't do local pickup. I think they pull from multiple warehouses so probably wouldn't be possible. Doesn't stop me from feeling a little annoyed to pay 20 bucks for shipping something heavy like rotors when I drive past their HQ all the time.

Hopefully you get the goods quickly tho!

But yeah, that's annoying.

[weehe126]

Originally Posted by AtlasM

As for Z4 35is 348x30 mm 2-piece rotors that would fit the 335i/xi, I've not yet been able to find any part numbers listed in the Pronto catalog, which is just pulling from showmetheparts.com. The BMW part number is 34116782593 and the best price I've found on them is $171.99 each at eEuroparts.

Just found them on sale and only $32 shipping:

https://parts.bmwofsouthatlanta.com/...116782593.html

$344.20 shipped, probably going to get them. Only $170 more than stock zimmermans

[weehe126]

Actually, the stoptech drilled/slotted on ECS are only $255/set. Does anyone know the weight on them? This link makes me think they are lighter than the Z4 2-peice at 22.5 lb each. http://www.e90post.com/forums/showthread.php?t=627141

And yes I know there is no performance gain to the drilled/slotted. This will only be for aggressive street use.

[Volasko]

Originally Posted by AtlasM

So far the only cheap 2-piece rotors I've been able to confirm are the Z4 28i/35i 330x24 mm size. They are:

DuraGo BR901054
Pronto 30422-05264501
Pilenga W0133-1935021

The US-market cars that use this size but come with 1-piece rotors are the E9x 330i/330xi and E84 X1 28i. There are tons of EU-spec cars that use this size, but most other US-spec E9x/E8x models use the smaller 312x24 mm rotors.
$171.99 each at eEuroparts.

Is there not another dimension other than 330x24 that matters when sizing rotors? When researching the above part numbers with online sites, most say the rotor will NOT fit an E90 330i. Found a supplier with Amazon.ca that would supply the DuraGo BR901054 for $90/rotor CAD + Free shipping that I'm seconds from clicking order, just not certain it will work.

[AtlasM]

Originally Posted by Volasko

Is there not another dimension other than 330x24 that matters when sizing rotors? When researching the above part numbers with online sites, most say the rotor will NOT fit an E90 330i. Found a supplier with Amazon.ca that would supply the DuraGo BR901054 for $90/rotor CAD + Free shipping that I'm seconds from clicking order, just not certain it will work.

Honestly I don't know for sure if they'll fit the 330i.

I do know that people have reported on here that they've been able to use 2-piece 348x30 mm Z4 35is rotors on their 335i. I also know if you pull up the part listing for Z4 35is rotors, they likely won't say they fit the 335i, because from the factory, they only come on the Z4.

If I were to guess, the same applies with the 2-piece 330x24 mm Z4 28i/35i rotors and their same-size 1-piece counterparts. But I haven't personally confirmed this.

[boro92]

Can confirm z4 35is rotors fit 335 calipers

[Volasko]

AtlasM did you end up trying any of these other two piece setups? If so how did you fare?

[StealYourFace]

Originally Posted by AtlasM

Honestly I don't know for sure if they'll fit the 330i.

I do know that people have reported on here that they've been able to use 2-piece 348x30 mm Z4 35is rotors on their 335i. I also know if you pull up the part listing for Z4 35is rotors, they likely won't say they fit the 335i, because from the factory, they only come on the Z4.

If I were to guess, the same applies with the 2-piece 330x24 mm Z4 28i/35i rotors and their same-size 1-piece counterparts. But I haven't personally confirmed this.

They'll fit a 330 if you get 335i calipers and caliper mounting brackets. Ive had this setup for years.

[Volasko]

Originally Posted by StealYourFace

They'll fit a 330 if you get 335i calipers and caliper mounting brackets. Ive had this setup for years.

Is there much difference between the 330i sport brakes vs. the 335i's? I thought they were pretty similar?

[lab_rat]

Originally Posted by Volasko

Is there much difference between the 330i sport brakes vs. the 335i's? I thought they were pretty similar?

This is a good question.

Are the 335i calipers really worth the "bang for the buck" upgrade on a 330i?

I would assume for a spirited daily street driven car, if I invest in Zimmerman solid rotors w/slightly aggressive pads (Hawk seems to be popular), then it would be nearly as good performance wise, correct?

I'm thinking it's better to put those possible "335i caliper funds" instead toward the M3 front/rear control arm upgrades, camber plates, or other upgrades for my daily 330i.

*Sorry about taking it slightly off topic

[feuer]

335i front brakes are good upgrade over the 330i front brakes. However if one is to swap calipers and rotors I would advised them to go with F30 Brembo 4 piston calipers and 340mm 2-piece rotors instead.

[StealYourFace]

Originally Posted by Volasko

Is there much difference between the 330i sport brakes vs. the 335i's? I thought they were pretty similar?

The 330i came with 13" rotors and a smaller caliper. With EBC yellows and high temp fluid I never had a problem at the Glen.

The 335i rotors are 13.7"... Similar feel, but I could brake a bit later, lap after lap. Again, never ran out of brakes at the Glen even on the hottest day.

Might be overkill for 260 hp , but I don't mind overkill in the brake dept. Plus they look better and have a lot of pad options.

It might be in my head, but I feel like the car is easier to trail brake due to a likely change in brake bias.

[tlow98]

Originally Posted by feuer

335i front brakes are good upgrade over the 330i front brakes. However if one is to swap calipers and rotors I would advised them to go with F30 Brembo 4 piston calipers and 340mm 2-piece rotors instead.

Not ce. What would be a good set up in the rear to balance this out?

[feuer]

Originally Posted by tlow98

Not ce. What would be a good set up in the rear to balance this out?

135i rear caliper with 5-series 330mm 2-piece rotor. Direct bolt on to 330i & 335i/d.

[tlow98]

Originally Posted by feuer

135i rear caliper with 5-series 330mm 2-piece rotor. Direct bolt on to 330i & 335i/d.

This sounds like a better setup than the stock E90 M3 setup. Hmmmm

[Volasko]

Originally Posted by feuer

135i rear caliper with 5-series 330mm 2-piece rotor. Direct bolt on to 330i & 335i/d.

Is it only a direct bolt on if you swap the rear caliper or will the original 330i caliper work? I'd love to have an aluminum hat rear rotor option!

[feuer]

Originally Posted by Volasko

Is it only a direct bolt on if you swap the rear caliper or will the original 330i caliper work? I'd love to have an aluminum hat rear rotor option!

Caliper + rotor.

[Volasko]

Originally Posted by Volasko

Is there not another dimension other than 330x24 that matters when sizing rotors? When researching the above part numbers with online sites, most say the rotor will NOT fit an E90 330i. Found a supplier with Amazon.ca that would supply the DuraGo BR901054 for $90/rotor CAD + Free shipping that I'm seconds from clicking order, just not certain it will work.

As a follow up I bought the above rotors and they do fit the front of my E90 330i. I only test fit them to check if they would work. I'll be able to compare weights when I actually install the parts. My only complaint is that the steel part of the rotor isn't coated with ANY type of anti corrosion spray, so right now I'm in the process of taping it off and coating it with a few coats of VHT header paint. The price was right though!