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-   -   Bigger brakes (https://forum.a8parts.co.uk/showthread.php?t=15773)

Audifan 13th July 2020 08:11 PM

Bigger brakes
 
I know I'm getting ahead of myself as I have other maintenance that needs to be done on my car but I don't care. I want to upgrade the brakes on my car and wondering if anyone installed 17z front calipers and Boxster (1st gen) calipers for the rear on the FL S8?

MikkiJayne 13th July 2020 08:47 PM

6-piston calipers with no provision for handbrake, on the rear? :Confused:

Audifan 13th July 2020 09:11 PM

Not 6-piston calipers for the rear. I'm looking to do 6-piston (17z) calipers for the fronts and 4-piston calipers for the rear. This guy uses a custom hydraulic e-brake setup for his rear 4-piston calipers

MikkiJayne 13th July 2020 09:42 PM

oh gotcha +++ I read that wrong!

A hydraulic handbrake is not allowed for road use here. We have to have something mechanical.

Aren't the 17z discs smaller than the stock FL S8 fronts though? 330mm I think, compared to the S8's 345mm. People seem to use a 345mm Mercedes ML disc with the 18z too so also no bigger.

I have attempted to figure out fitting an 18z caliper to a 365mm RS4 front disc, but could see no way for it to work as the mounting lugs for the caliper and upright both occupy the same place, so I'm keen to see what you come up with. It would be much easier with radial mount calipers. That said, it might be possible with the ML disc. Just no upgrade in size, although the Porsche monoblock calipers appear superior to the S8 Brembos in pretty much every way.

It springs to mind actually that I don't think I've tried the 18z caliper with a stock S8 disc. Hmm...

Audifan 13th July 2020 10:05 PM

It's ok, no worries.

Bummer to hear. The other option is try and custom fit these for mechanical setup.

Yes they list the 17z calipers to use 330mm discs and 18z calipers to use 345mm discs but I'm sure you can use larger discs for either calipers. After some searching this guy is using 350 mm discs with 17z calipers

I did some more searching and found that the C5 RS6 and B7 RS4 use 8-piston calipers and 365mm discs. So I guess the other option is to try and fit 8-piston calipers for the front and use 365mm discs. Will these fit with 18" wheels?

MikkiJayne 13th July 2020 10:24 PM

I've done B7 RS4 brakes on a D2. Thats easy as they are radial mount calipers the same as the D2 Brembos so the adapter is a 10mm thick flat plate with 4 holes in it. I would expect they fit in some 18s as thats what the B7 had stock, although the RS6 had 19s.

The 18z will fit over a 365mm disc no problem - it just needs a litle grinding at the outer edges. But, the mounting lugs then occupy the same place in space as the lugs on the upright so you can't even put the caliper on the disc, let alone contrive an adapter. I'll get a pic tomorrow - its a vexing problem since those calipers are cheap and easily available.

Stromaluski 14th July 2020 01:41 PM

I would think it would be easier to simply swap to D2 A8 spindles and then use D3 brakes? D3 A8 have 360mm rotors. D3 S8 are 385mm rotors.

Audifan 14th July 2020 02:47 PM

Quote:

Originally Posted by MikkiJayne (Post 158561)
I've done B7 RS4 brakes on a D2. Thats easy as they are radial mount calipers the same as the D2 Brembos so the adapter is a 10mm thick flat plate with 4 holes in it. I would expect they fit in some 18s as thats what the B7 had stock, although the RS6 had 19s.

The 18z will fit over a 365mm disc no problem - it just needs a litle grinding at the outer edges. But, the mounting lugs then occupy the same place in space as the lugs on the upright so you can't even put the caliper on the disc, let alone contrive an adapter. I'll get a pic tomorrow - its a vexing problem since those calipers are cheap and easily available.

Yes please post some pictures. It sounds like I might go this route

Audifan 14th July 2020 02:52 PM

Quote:

Originally Posted by Stromaluski (Post 158569)
I would think it would be easier to simply swap to D2 A8 spindles and then use D3 brakes? D3 A8 have 360mm rotors. D3 S8 are 385mm rotors.

Yeah but how is 2-piston (which are on the same side) calipers better then 4, 6 or 8 piston calipers!?!

Stromaluski 14th July 2020 06:04 PM

Quote:

Originally Posted by Audifan (Post 158572)
Yeah but how is 2-piston (which are on the same side) calipers better then 4, 6 or 8 piston calipers!?!

Depends on how you qualify one setup as being better than another.


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