Reducing brake disc diameter

[Rusty]

Just looking in to my ultimate brake setup to fit under Avus 16s and unfortunately, 996s and the rear vented 323s are a no-go. The 314s fit perfectly but are front vented, although there are holes in the hat, so they don't lend themselves as well to brake cooling ducts from the rear of the disc... There is a 321mm A6 disc but again, that's front vented

Some research indicates that with a 10mm hub spacer, I can run something in the region of 319-320mm discs, so was a considering turning down some 323mm but I'm concerned about the balance of the disc, as this is normally done on the OD.

Other option is custom 2 piece but that's a bit exotic...

[Error404]

I'm going to go to 2-piece next time I need new discs

[Rusty]

But £££££££££

[johne]

The 314s fit perfectly but are front vented, although there are holes in the hat, so they don't lend themselves as well to brake cooling ducts from the rear of the disc

If I understand what you're getting at - and I'm not sure I do - can the backing plate be changed to help get the correct (better) airflow?

John

[driftin jo]

If I understand what you're getting at - and I'm not sure I do - can the backing plate be changed to help get the correct (better) airflow?

John

Yer,if you make it a fronting plate instead of a backing plate

[Rusty]

Feeding air to the hat may work due to the holes in it but a rear vented disc would be better still. A custom backing plate with a 2" pipe welded to it is on the to do list too.

[Error404]

I won't go any larger than thr 314s due to the huge weight of big single piece discs!
Hi-Spec rotors are pretty good money and made by AP I believe
They also do a nice looking 300 x 22 rear rotor

[Rusty]

320x28 would be £250 a pair or so. How much extra are bells?

[sam80quattro]

friend of mine turned down some discs by around 20mm to fit his pulsar gtir and never had any wobbles or anything untoward, daily driving track/drag toy..

[europeanme]

I turned my new discs down, granted only by 5mm but as long as you keep the largest braking surface area you can, it shouldn't matter...

http://www.bigbrakes4u.co.uk/ speak to Gareth, they do some good 310mm kits, granted 2 piece but how cool will they look

[Rusty]

I already have 314s but just musing. Would need 323s taking down to 319-320 but hardly seems worth it for now.

What thickness discs do the 429/430 GT3 take?

[Error404]

32mm I believe. I was planning to use the 330 x 32 rotors with the 429/430 GT3s as they have a 62mm annulus so will work nicely.

[Henkjan]

300mm S4's are not good enough for ya?

http://www.s2forum.com/forum/showthread.php?t=62766

[PRY4SNO]

Considering how little heat the rear brakes get vs. the fronts wouldn't a set of OEM b5s4 or d2s8 rear rotors do the trick? Beefy, vented, affordable, available mostly everywhere... and they'll probably even fit the 16" Avus'.

Or am I missing some awesome track day where you/someone did some testing?

[Rusty]

320x32 with the bigguns is interesting... Wonder if 314x30 would work?