Front discs 2009 E89 Z4 30i

[ajguk]

Hi

I need to replace the front discs on my E89 Z4, sDrive30i.

Eurocarparts only have the ATE discs, but I've seen Mtec mentioned in several places. The only problem (?) I can see with these is I can only get drilled/grooved etc, not flat ones. This only bothers me because of varying opinions that say such discs can be noisy, whereas many people have no issue.

I'm leaning towards EBC Redstuff pads if that makes a difference, although only because they are on the Mtec site. Discs and pads coming out around £150 on there at the moment, but I'm happy to pay more to avoid any squeals!

Does anyone have any recommendations?

Thanks

[E-bmw]

DON'T USE EBC PADS THEY ARE SH!T!!!!!!

Ate are OEM & perfect for the car.

Grooved/drilled are only of any use to you if you are tracking the car, and going for a PROPER pad upgrade, so don't bother otherwise.

[ajguk]

Are Eurocarparts the cheapest place for these (after the discount code I'm looking at £265 for ATE discs and pads)?

[GreenV8S]

ajguk said:

I can only get drilled/grooved etc, not flat ones. This only bothers me because of varying opinions that say such discs can be noisy, whereas many people have no issue.

The drilled discs you're talking about will be drilled cast iron discs. These are fine for show cars where the only requirement is to look 'motorsporty' but not suitable for cars that will actually be driven, especially if they're going to be driven hard enough to need the extra gas dispersion. All discs that get hot are vulnerable to fatigue cracking from thermal expansion. If the brakes are used hard enough for heat related issues to be relevant then the discs need to be monitored and replaced when cracks inevitably develop. Drilled cast discs are far more vulnerable than plain/grooved discs and will need replacing sooner. If they are not monitored and replaced in time, the resulting failure can be catastrophic.

The expensive sports cars and race cars with drilled discs will either be using discs made from a different material, or with the holes cast in rather than drilled. They cost massively more than the ordinary aftermarket discs you'll be looking at.

If the brakes get hot enough to need extra gas dispersion to avoid brake fade, use grooved discs rather than drilled - or use pads that are designed for the higher temperature.

If the brakes don't get hot enough to need the extra gas dispersion, use plain discs - they give better performance and less noise and wear.

[ajguk]

Thanks - I have been looking for smooth discs but I could only find the ATEs. The Mtecs get varied reviews and as I mentioned I wasn't keen on drilled or grooved. So, are there any other brands or are the ATEs as good as OEM?

[ajguk]

Ok so the pads were 20% worn (according to service report) 4k miles ago. Shall I just change the pads too while I'm at it or is this unnecessary?

Cheapest place seems to be ECP for the ATE discs and pads.

[GreenV8S]

ajguk said:

Ok so the pads were 20% worn

No reason to change them.

[helix402]

Try Car Parts 4 Less, same company as Euros but online only. ATE pads and discs are good. Don’t forget the wear sensor.

[E-bmw]

ajguk said:

Thanks - I have been looking for smooth discs but I could only find the ATEs. The Mtecs get varied reviews and as I mentioned I wasn't keen on drilled or grooved. So, are there any other brands or are the ATEs as good as OEM?

Mtec are sh!t.

[ajguk]

I've gone with ATE from Eurocarparts. £215 delivered I think.

MOT advisory last Feb (3000 miles ago) has both sides "front brake fluctuating, but not excessively" and I know the discs are on the limit, so I guess I'll check the pads too when I replace the discs and change them too if necessary.

[Dave Brand]

If you're replacing the discs it makes sense to replace the pads!

[E-bmw]

^^^^ Wot 'e said.

[ajguk]

I better order some them!

ATE to go with the discs or could I go Brembo or Bosch?

[GreenV8S]

Dave Brand said:

If you're replacing the discs it makes sense to replace the pads!

If the pads still have 80% life left as described below there's really no reason to discard them.

[ajguk]

It was the fluctuation on the advisory that bothered me. If this was down to the disc, could it have damaged the pad.

[E-bmw]

GreenV8S said:

Dave Brand said:

If you're replacing the discs it makes sense to replace the pads!

If the pads still have 80% life left as described below there's really no reason to discard them.

Whilst part of me will agree with that sentiment, for the price of them & the fact that they bed in better with all new parts, I would always fit new & keep good ones in case of uneven wear rather than buy a full set in the future personally.

[ajguk]

Cheers all - ordered the ATE pads as well. Obviously forgot the wear sensor so had to go add that on as well....

[GreenV8S]

E-bmw said:

they bed in better with all new parts

It shouldn't make any difference unless the pads have been overheated or unevenly worn. Some brands explicitly advise to change them separately (bed in new discs with mature pads rather than new pads) so you aren't trying to condition the discs at the same time the pads are gong through their initial heat cycles.

[LaPetiteMort]

Hi
Being cheeky and jumping in on this thread!
I was just looking for discs and pads for my E89 35i, thank you for those who have pointed in direction of ATE as OEM

I had a question on the wear sensor, ATE have two different ones for my car, they are different lengths and the pictures look slightly different. One is 1013mm and the other is 969mm, does anyone know how I can tell which one I need?

BTW I use https://www.buycarparts.co.uk/ which I think is the same company as autodoc, for parts I have ordered they have been brilliant both in service and price. Also you can get cashback on Topcashback for buycarparts

[E-bmw]

It could be one for front & other for rear.

You could always measure the fitted one to confirm which.