I will be putting on some Porsche 986 Boxster 4-pot front calipers over standard 312mm discs and was wondering if they will fit under 18" Zenith alloys with enough room to clear or if I'll need to get spacers.

I believe that these are the same dimensions as the Boxster S rear calipers that are another common brake mod.

Would appreciate feedback from anyone who has seen/tried this set up.

Thanks

Edited 17 June, 201016 yr by muckipup

A few guys on the Mk5 site use Porsche set ups not sure which ones but they mostly have them under 18" wheels.

If I can fit an R32 kit which is 345mm discs and bigger callipers under 17's I'm sure that just adding callipers would be fine.

Are you sure they will work with the 312mm disc? You will have to check the disc thickness.

A few guys on the Mk5 site use Porsche set ups not sure which ones but they mostly have them under 18" wheels.

If I can fit an R32 kit which is 345mm discs and bigger callipers under 17's I'm sure that just adding callipers would be fine.

Are you sure they will work with the 312mm disc? You will have to check the disc thickness.

Thanks Carl,

I know from some of the MkV chappies that this set up is a tight fit under 17" Monzas and needs a spacer, even if only a 3mm one. Although I am on 18" Zeniths, the Monza design looks like it has a few mm more room.

The discs will fit OK although the Porsche 24mm thickness means that the pad retaining pegs on the calipers need to be ground down by a mm or so to accommodate the 25mm thickness of the 312 discs. Very easy though as these are alluminium/alloy calipers and therefore soft enought to be filed or Dremeled.

dificult to say really. speak to daveB and ask him if there are any measurements you can make against the std calipers and the 18" zeniths. that way you can determine the clearance and compare them to the 18" monza's on the GTI

Well Monzas are 7.5J x 17 ET51 (Obviously the 18's are bigger )

Zeniths are 7.5J x 18 ET51 so you "should" be ok i reckon

Edited 17 June, 201016 yr by vRSCarl

Well Monzas are 7.5J x 17 ET51 (Obviously the 18's are bigger )

Zeniths are 8J x 18 ET51 so you "should" be ok i reckon

Yeah, I think you are right. I just found a Boxster in my works car park and measured the distance from the disc to the widest part of the caliper. It was about 58mm tops. The gap between my disc and the alloys is about 60 at the narrowest and 63mm from the outside edge of the disc (which would be the bit that approximates to the widest part of the caliper). I couldn't hang about and be too accurate as I looked well dodgy with a plastic ruler sniffing around a Porsche.

In summary, I'm hoping to have about 5mm clearance...famous last words!!

Edited 17 June, 201016 yr by muckipup

Locate a supplier for the spacers that is local, then give it a go and make sure you have a way to get spacers if required?

Just put spacers on anyway FTW

I did

Zeniths are 8J x 18 ET51 so you "should" be ok i reckon

7.5J

7.5J

oops my bad will edit now

Locate a supplier for the spacers that is local, then give it a go and make sure you have a way to get spacers if required?

Just put spacers on anyway FTW

I did

Both very sensible bits of advice I'll probably get them to be safe and if I don't need them then there's always ebay...or I may just like them anyway even if I don't need 'em :yes: