(Relatively) Low cost Big Brake Kit (BBK) for the non 35i E89s

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Pbondar
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(Relatively) Low cost Big Brake Kit (BBK) for the non 35i E89s

Post by Pbondar » Mon Jul 19, 2021 5:19 pm

Gearbox wrote: Mon Jul 19, 2021 5:11 pm hi Just reading through this thread... and interested to do this... Did you get the '35i rear callipers from the US just so you could refurb them and not lose the use of your car, or was there another reason. I have just compared the 35i and the 20i realoem parts list and they seem to be the same?

Cheers...
I screwed up..in the UK and Europe 35i AND 35is have the same over size rear caliper..

In the US the 35i has the same size caliper as the 18/20/23/28/30 only the 35is has the oversize rear caliper..

I was in the process of buying two 35is rear calipers ..ordered the parts then the seller said he couldn't find one side..absent minded went to another US supplier with a35i not 35is (forgot the US only issue)..
2012 E89 N20 MSport Auto Atacama Yellow Fully Loaded plus some..details here.. https://www.dropbox.com/s/yqrmrnxmh7tq6 ... e.pdf?dl=0

jenniferlouise
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(Relatively) Low cost Big Brake Kit (BBK) for the non 35i E89s

Post by jenniferlouise » Tue Jul 20, 2021 4:03 pm

Hi Gearbox, the technical know-how belongs to others on here, however my understanding - which I think is captured in the thread - is all Z4 have the same rear discs and callipers from 20i to 35i with the 35is being the only exception. I’m sure I’ll get corrected if I’m wrong. :(

The callipers on the rear of my car were reconditioned by Bigg Red in Worcestershire here: http://biggred.co.uk/ and I have been fortunate to secure BMW replacement discs and pads to compliment. :thumbsup: Bigg Red appear to stock and sell refurbished brakes so may be worth a phone call. Otherwise it’s a case of sourcing a pair and having them reconditioned.

I believe the US issue you refer to was our friend trying to source the larger callipers from wherever possible to accompany a max size rear disc. Again I apologise if I’ve got that wrong!

I have to say they look a great match with the #…734 OEM Performance yellow front callipers, and again were easily fitted without any complications.

BMW will happily supply the front kit but will tell you they cannot recommend as, technically, there is no BBK upgrade for the Z4. This probably then calls in to doubt any future warranty, if you needed to do so. However my local BMW Specialist https://bartlett-auto.com/ supplied and fitted mine with no problems and if I had any issues it would go back to them.

It’s an expensive option, one that is unlikely to pay itself back when selling, but it looks sooo much better and probably gives improved stopping… I’ll let you know when I’ve actually done enough miles to bed them in.

Hope that helps a little. A

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(Relatively) Low cost Big Brake Kit (BBK) for the non 35i E89s

Post by Pbondar » Tue Jul 20, 2021 5:00 pm

The primary issue is that 35is rear calipers (or 35i rear calipers in Europe) are like hen's teeth..cost me the best part of £300 in parts to 'build' a 35is rear caliper set using used parts then £235 for a biggred refurb..with discs you are into £700 ish for a quality rear disc set

Given that the E89 has a great DCS system you can use that to get the most out of the standard rear disc /caliper.. they are much cheaper and get a nice re-furb on it!
2012 E89 N20 MSport Auto Atacama Yellow Fully Loaded plus some..details here.. https://www.dropbox.com/s/yqrmrnxmh7tq6 ... e.pdf?dl=0

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