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Discussion Starter · #1 ·
Does anyone know the diameter and the weights of the 123d vs 135 and BMWP brake discs and calipers?

I understand the 123 has a bigger set up than the lower 1s but obviously lacking the six pot callipers of the 135.

Thanks guys.
 

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RMB123d said:
Does anyone know the diameter and the weights of the 123d vs 135 and BMWP brake discs and calipers?

I understand the 123 has a bigger set up than the lower 1s but obviously lacking the six pot callipers of the 135.

Thanks guys.
123d has 330mm front and 300mm rears
135i has 338mm front and 324mm rears
MP has 370mm front and 345mm rears

As for weights of both the calipers and discs can't help you there
 

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Discussion Starter · #3 ·
Oh thanks.

I'm surprised only a small difference between 123 and 135, and again surprised BMWP is that much bigger again.

I like the idea of the BMWP full kit but don't like the fact front and rear discs don't match as the rears aren't drilled.
 

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RMB123d said:
Oh thanks.

I'm surprised only a small difference between 123 and 135, and again surprised BMWP is that much bigger again.

I like the idea of the BMWP full kit but don't like the fact front and rear discs don't match as the rears aren't drilled.
I was bloody suprised the other day when I needed two nee discs and pads ! The brakes on the 123d are quite overkill especially when freshly serviced. Mine has had a fluid change as well and it stops insanely
 

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Discussion Starter · #5 ·
Yeah, they aren't too bad at all. I may upgrade only if they wear out.

You should put you car details on your signature.
 

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RMB123d said:
Oh thanks.

I'm surprised only a small difference between 123 and 135, and again surprised BMWP is that much bigger again.

I like the idea of the BMWP full kit but don't like the fact front and rear discs don't match as the rears aren't drilled.
Both front and rear BMWP discs are drilled so they will match? If you get the rear calipers as well I mean.

But even so some aftermarket discs on the rear even if you keep the standard rear brake calipers will sort that out.

They look great, but over kill on a road car. The standard brakes are more than sufficient.

Plus the 6 pots don't gold up that well on track either, the pistons crack.

More I look into it the more tempted I am to try the newer f series calipers.
 

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The mono block calipers ( ones found on 135i or m135i ) weigh a lot less than the cast sliding calipers , not sure on how much the disks weigh but it's not going to be a massive difference. You
 

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When I changed my standard 130i brakes for a set of six pot WP brakes with 360mm discs I lost a fair amount of weight. Callipers; 6kg OEM single piston versus 4kg for the six piston WP items. Front discs; 8.7kg OEM 330mm versus 7.5kg for WP 360mm drilled floating disc. Similar weight savings on the rear for a four piston set up. I doubt you'd get any weight savings with the 135i/ M Performance set ups as I think they still use a larger one piece disc and the callipers haven't been machined to lose weight where its not required for the calliper stiffness. They do look good though and your braking would be improved for fast road driving.
 

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Discussion Starter · #9 ·

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jonwilli said:
I think the BMWP discs are dimpled not drilled
RMB123d said:

From this website it appears the BMWP rears are solid on the 123/135 set up.

Is this not correct, anyone have any pics of their car?

Thanks and thanks all for the info so far.
Part number for the bmwp rear discs coming up for a 130i, same kit as the 123 kit on rear OEM


Plus the real oem listing actuslly day this: Brake rotor, ventilated, drilled, rear 324X22 2
34216795755

I have seen them in the flesh. The actual BMWP rear brake discs for the hatch, 123d 130i are 100% drilled.

I'm not sure about the 135 but I'm pretty confident they are drilled on those too.
 

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It's a bit of a minefield to be fair, more than likely down to superseeded part numbers? BMWP discs are/have been available as Dimpled and Grooved, Drilled and Grooved, and Solid.

So there you go... It's all clear as mud! :lol2:
 

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I've got the 335i front callipers on my 123, they are slightly lighter than the stock 123 single pots. The disks are 348 so 18mm bigger than 123.

I found the 123 setup underwhelming at high speed, not enough bite/torque for me.. My new setup with Red stuff pads Goodrich lines, Castrol fluid and grooved disks is great. The lines firm up the pedal nicely and under fast road conditions I could not be happier, low dust too....

No track work, Id change the pads for something more focused if I do a track day.

The pads do need a little heat to bite properly, plenty enough from cold but they certainly feel better after getting some temperature into them, I like a light pedal and they require very little pressure to pull the speed off. Only issue I have now days is driving other cars and realising how good my brakes are...

R88
 

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Discussion Starter · #15 ·
jonwilli said:
When I changed my standard 130i brakes for a set of six pot WP brakes with 360mm discs I lost a fair amount of weight. Callipers; 6kg OEM single piston versus 4kg for the six piston WP items. Front discs; 8.7kg OEM 330mm versus 7.5kg for WP 360mm drilled floating disc. Similar weight savings on the rear for a four piston set up. I doubt you'd get any weight savings with the 135i/ M Performance set ups as I think they still use a larger one piece disc and the callipers haven't been machined to lose weight where its not required for the calliper stiffness. They do look good though and your braking would be improved for fast road driving.
How much was this set up Jon? Got any pics?

Thanks

Rich
 

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Discussion Starter · #16 ·
0l0dom0l0 said:
jonwilli said:
I think the BMWP discs are dimpled not drilled
RMB123d said:

From this website it appears the BMWP rears are solid on the 123/135 set up.

Is this not correct, anyone have any pics of their car?

Thanks and thanks all for the info so far.
Part number for the bmwp rear discs coming up for a 130i, same kit as the 123 kit on rear OEM


Plus the real oem listing actuslly day this: Brake rotor, ventilated, drilled, rear 324X22 2
34216795755

I have seen them in the flesh. The actual BMWP rear brake discs for the hatch, 123d 130i are 100% drilled.

I'm not sure about the 135 but I'm pretty confident they are drilled on those too.
Thanks Dom,

This seems to only show for hatchbacks, mine is an E82 123.

I know the BMWP full kit is the same for the E82 123 & 135.
 

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RMB123d said:
jonwilli said:
When I changed my standard 130i brakes for a set of six pot WP brakes with 360mm discs I lost a fair amount of weight. Callipers; 6kg OEM single piston versus 4kg for the six piston WP items. Front discs; 8.7kg OEM 330mm versus 7.5kg for WP 360mm drilled floating disc. Similar weight savings on the rear for a four piston set up. I doubt you'd get any weight savings with the 135i/ M Performance set ups as I think they still use a larger one piece disc and the callipers haven't been machined to lose weight where its not required for the calliper stiffness. They do look good though and your braking would be improved for fast road driving.
How much was this set up Jon? Got any pics?

Thanks

Rich
Yeah, have a look on my build thread (link on my signature)
 

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Discussion Starter · #18 ·
Thanks Jon,

Great thread, the WP kit looks amazing and no doubt expensive, I couldn't see the price in the thread?

I'll probably just upgrade the parts as they need replacing though.

Rich
 
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