Bolt on bigger brake discs

[james911996]

Hi all,

Was wondering if anyone has come across a spacer kit available to fit in larger brake discs from later models?
I have a 2002 C2 and other than the Girodisc floating discs kit (which is pretty expensive) i have seen nothing that just bolts on. I have the GT3/ Sport Design wheels. Surely it must be possible to fit some slightly bigger rotors from a 997 or something with some spacers to use the original callipers?

Thanks for any help!

 

[coullstar]

Are you struggling with the standard ones? I've never found them that lacking so maybe try some better pads or other discs and get the cooling ducts.

I've used girodisc on another car and they are a lot lighter for sure.

 

[james911996]

@coullstar

Not exactly struggling with them. Here is my issue:
- i did about 3500 road mile (easy, most motorway) and 4 track days last year. brembo hp2000 pads, braided hoses and race fluid
- after 4 track days i started to feel the brakes being week and my mechanic looked and said 'there loads of pad left but they have badly crumbled due to heat cycle'
- i'm aware i could go with pagid RS19 of performance friction pads and avoid that, but i read everywhere they are unbearable for road use. Super loud brakes are not really an option from weekend countryside trips with my wife..
- i live in central london with no garage and park on the street, so changing pads before and after track days is not really an option for me.

SO really i'd Love a set up that allows me to run road friendly pads on track days. I'm trying the EBC blue stuff (just went on but not tried yet) and hoping they will help. But more is more! So bigger discs i think could go a long way to help.

 

[james911996]

And here are some pics of my baby:

 

[james911996]

I've used girodisc on another car and they are a lot lighter for sure.

Can you actually feel the weight difference? How was the braking improved?

Thanks!

 

[coullstar]

Weight difference was noticeable when installing but didn't notice much if any difference driving.

They worked well and looked the part, rusted up really quickly so watch if the car is left for longer periods that the corrosion doesn't get too bad.

It does sound like slightly bigger discs will help with heat dissipation and a longer lever for braking. Do you have the GT3 brake ducts installed as it does sound like cooling would help?

 

[Pip1968]

@coullstar

- i'm aware i could go with Pagid RS19 of performance friction pads and avoid that, but i read everywhere they are unbearable for road use. Super loud brakes are not really an option from weekend countryside trips with my wife..
- i live in central London with no garage and park on the street, so changing pads before and after track days is not really an option for me.

I usually swap the pads over between OEM pads and Pagid RS-29s for track days (fronts only - I cannot remember if the rears are OEM or RS-29s all the time but I do not change them). I have frequently left the RS-29s in for road driving and have not had an issue with them noise wise.

I should add that my car is not used for commuting or short journeys so 25 miles or a long day out with shorter trips. RS-29 like hard breaking and not constant dabs that many poor drivers do because they are driving too close to the car in front. I am sure that RS-19s will be similar although possibly better for road use - less abrasive/aggressive.

Personally I would give them or the RS-19s a go. If the car sits around it may initially be worth a couple of hard stops initially to clear the rust from the discs.

Pip

 

[Shalmaneser]

I got in touch with Compbrake about upgraded sizes - 330 front and 310 rears to mirror the existing size differential. £900 all in including all fixings (but excluding spacers seemed pretty reasonable.

Will give it some thought when my existing discs need replacing.

Email Klint on [email protected].

 

[crash7]

How many brake fluid changes have you completed with the high temp fluid?

It can take two or three to really gain the full benefit as you need the ABS & PSM to cycle/activate to ensure all of the old stuff has been completely flushed out.

I run Giro discs but have previously tracked on standard rotors, as you say its the heat disapation that is the issue, 997 GT3 front and rear brake ducts help, but are not miricle workers.

RSL29 seem to be the default recommended brake pad, its either standard or RSL29, when actually there are a mulitltude of pads that sit between the RSL29 which is a race endurance pad, and the standard OEM pads.

Dont get me wrong RSL29's are good for track, I run them, and they can be tolerated on the road, however the fact remains that they are a race pad and not designed for the road cold bite is not good and if you dont regularly get heat into them they will squeal.

I would recommend trying Pagid RS42 which would be superior to the HP2000 but not as aggressive as the RSL29.

In regards to alternate disc solutions, I could not find any, however provided you can find a disc with the same offset, there is no reason why it would not work, the front Giro are 340mm the extra disc size is accomodated by adding two simple spacers between the knuckle and the caliper.

 

[james911996]

Do you have the GT3 brake ducts installed as it does sound like cooling would help?

I was going to put them on but was told they hang pretty low and scrape everywhere. The car is quite low already (lost the cup splitter in the night a few weeks ago...) and can't leave my home without going over hundreds of speed bumps. The people that look after my car didn't seem to know if the cup or the GT3 ones would be the best. What's your experience?

 

[james911996]

Personally I would give them or the RS-19s a go. If the car sits around it may initially be worth a couple of hard stops initially to clear the rust from the discs.

Pip

Thanks for the feedback Pip.

I'll have to try them at some point but I've heard of people having really bad experiences of them on the road. Maybe Blue rs4.2 are a good compromise.

How long does the pad swap typically take for you? Also - any issue with having different pads front and rear? Doesn't that mess up brake bias?

 

[james911996]

I got in touch with Compbrake about upgraded sizes - 330 front and 310 rears to mirror the existing size differential. £900 all in including all fixings (but excluding spacers seemed pretty reasonable.

Will give it some thought when my existing discs need replacing.

Email Klint on [email protected].

That's really interesting, thanks for sharing.
So I imagine this is floating disc set up for four corners? That's less than half the price of the girodiscs.
How would you go about getting the right spacers made?

 

[james911996]

How many brake fluid changes have you completed with the high temp fluid?

It can take two or three to really gain the full benefit as you need the ABS & PSM to cycle/activate to ensure all of the old stuff has been completely flushed out.

I run Giro discs but have previously tracked on standard rotors, as you say its the heat disapation that is the issue, 997 GT3 front and rear brake ducts help, but are not miricle workers.

RSL29 seem to be the default recommended brake pad, its either standard or RSL29, when actually there are a mulitltude of pads that sit between the RSL29 which is a race endurance pad, and the standard OEM pads.

Dont get me wrong RSL29's are good for track, I run them, and they can be tolerated on the road, however the fact remains that they are a race pad and not designed for the road cold bite is not good and if you dont regularly get heat into them they will squeal.

I would recommend trying Pagid RS42 which would be superior to the HP2000 but not as aggressive as the RSL29.

In regards to alternate disc solutions, I could not find any, however provided you can find a disc with the same offset, there is no reason why it would not work, the front Giro are 340mm the extra disc size is accomodated by adding two simple spacers between the knuckle and the caliper.

Thanks for the insights.

On fluid - I had it done once but rpm technik who look after my car for most of the work (though they are far from home so not all). Pedal felt much better after but that is also done to the lads I think (was some really cheap stuff from previous owner on there).

Ive read up a little on the RS42 and they seem to fit the bill. If the EBC blue don't work they probably be the next I try.

On alternate discs I would have thought it would be an easy and cheap way to improve things so I'm surprised no one offers a cost effective solution. Will investigate further..

 

[Dammit]

I have the GT3 ducts, live in Zone 2 where we have plenty of speed bumps and I don't recall scraping them. They're also so cheap that if they do get a bit haggard I'll just replace them.

 

[Shalmaneser]

I got in touch with Compbrake about upgraded sizes - 330 front and 310 rears to mirror the existing size differential. £900 all in including all fixings (but excluding spacers seemed pretty reasonable.

Will give it some thought when my existing discs need replacing.

Email Klint on [email protected].

That's really interesting, thanks for sharing.
So I imagine this is floating disc set up for four corners? That's less than half the price of the girodiscs.
How would you go about getting the right spacers made?

Quite right, floating discs all round. It seems a great deal. Compbrake are a good supplier, too.

Spacers are trivial to make if you have a lathe but are available very cheaply:

https://www.ebay.co.uk/itm/Brake-Sp...116553?hash=item3651b60209:g:FmYAAOSwFNZWyYFp

all you need then are the correct bolts which Porsche can supply:

99906705009 pan-head screw M 12 X 1.5 X 77

or can be bought from various reputable suppliers in 12.9 spec:

https://www.westfieldfasteners.co.uk/BZP-12.9_ScrewBolt_SHCap_M12.html