Brake upgrade.

[Andiroo]

drilled for show and slotted for go (or stop !) is an expression you will hear if you ask brake designers the question, just take a look at the brakes on every front engined racing GT car that has a similar mass to the B5 and you will find slotted discs.

As to heat dissipation, this is a product of the surface area of the rotor (bigger rotors are better), the area of the caliper, design of the rotor veins (if any) and how air is circulated to the brake system. A 2-pot Porsche caliper is unlikely to dissipate heat quicker than a 8-Pot Brembo caliper.

I agree with you up to a point Jeff, particularly in respect of slotted versus drilled discs point.

My only concern, relating to my above post, with particular regard to heat dissipation is the pad area - overall the pad surface area is greater on the 2 pad Porsche compared to the 4 pad Brembo - which you seemed to miss in your above post.

The area of the caliper will come into it in a small way, but not as much as the surface area of the pad in comparison. Smaller pad surface area means more heat to dissipate, which would make me stay with the 2 pad Porsche, again IMHO

Cheers,

Andiroo

[simoncotton]

Do 380mm brakes fit under 18" wheels?

yes i'm running 380mm discs on mine, with the standard 18" wheels. the discs are huge, nearly as big as the inner wheels.

qstuning fit them as part of their upgrade package - i think for the front and rears your looking at 2.5k

[jeffw]

The heat is mainly dissipated by the rotor size and design which will minimise the heat soak into the Pad and then the calipers and brake lines. Larger pads will have more breaking effect and I agree, better heat dissipation from the pad itself. But a 380x34 disc with the Brembo 8 pot caliper (4 pad) will have better heat dissipation and better braking effect than a 360x32mm rotor with the 4 pot Porsche caliper. By far the biggest impact on braking performance and heat dissipation is rotor size and design....bigger is better

[Andiroo]

So bearing that in mind, like for like rotor size, ie 380mm like the Sportecs I ran and the GT3's I had on the Cup, plus like for like pad material - which would you say would be the better at heat dissipation Jeff?

Cheers,

Andiroo

[jeffw]

Like for like down the line it would be the caliper with the largest pad, but there will not be a lot in it. If you do what I do (and shouldn't) which is brake progressivly on a track day changing to "brake as hard as you can for the shortest time possible" will reduce temperature significantly.

[Andiroo]

Thanks Jeff, sort of supports my logic staying with the Porsche Brembos for the 'ultimate' so to speak, plus I suppose I've always been swayed a bit with probs that the RS6's and first Lambo Gayardo's had with the 8 pots on track. But these B7 Brembos must have come on leaps and bounds since then, possibly using better pads - and for the difference in price they sound really cool mate

Cheers,

Andiroo

[jeffw]

If you want the "Ultimate" caliper then you should be looking at AP Racings 8 Pot water cooled caliper which runs 40mm discs Of course you could also look at carbon or ceramic discs and pads.

[quattrokid1]

are these suitable
http://contact.ebay.co.uk/ws/eBayISAPI.dll

[jimbo1234567]

ebay page not responding

[tdiquattro]

Just out of interest, and because I am always looking for alternatives, I am thinking of experimenting with one piece 360mm cast iron alloy disks.

Can the experts say what the disadvantages would be except weight?

Basically you can buy today a pair of plain discs from an A8/S8 that are 360mm vented fronts.
How do they compare to 360mm RS4 B5 discs (rotor and integral hat)
or 365mm B7 (bolt on rotor and hat)

Does anyone know if they are the same offset, ie will they line up the same?

Please don't write them off straight away, I would rather discuss the merits, oh and I have Porsche big reds on genuine Porsche movit 322mm rotors so it is not just about price.

Thanks

[jeffw]

It is likely that in normal day to day drive they will have the same abilities as the aluminium centred versions. Disc size and width is the major factor in disc performance, followed by grooved, x-drilled or plain then the vanes in the disc are shaped. The big difference you'll find is weight, this will effect your unsprung weight significantly. The other difference will be heat dissipation ...not sure if the aluminium will be better than cast iron. Probable worth a go but I would think that the material used wouldn't be on the same level as 'sport' discs.

[K2]

I'm running Porsche 996 GT3 Cup 6 Pot Brembo callipers with RS6+ front discs, (cross drilled) and yellow pagid pads, which have worked very well indeed, loads of stoping power and plenty of peddle feel.
Pagid do quite a few pad aoptions for these callipers which will suite pretty much any road or race appliction.
I can send you the part numbers of the callipers if you like.

[tdiquattro]

I'm running Porsche 996 GT3 Cup 6 Pot Brembo callipers with RS6+ front discs, (cross drilled) and yellow pagid pads, which have worked very well indeed, loads of stoping power and plenty of peddle feel.
Pagid do quite a few pad aoptions for these callipers which will suite pretty much any road or race appliction.
I can send you the part numbers of the callipers if you like.

Funny you should mention that so have I !, just looking at disc options, what did you do for adapters?, mine are the genuine 6 pots and they have the radial mounts. I have a set of pagid yellows.
I am thinking 360m or 365mm will be fine, I have 18" wheels.
Are the RS6+ 365mm ? how much do the pads cover on the surface of the discs? if I had adapters for 360mm could I go to RS6 discs later on with the same adapters?

Thanks in advance,

oh and thanks for the reply jeff very helpful, I am still thinking about experimenting with both types.

[K2]

Nige
Dialynx fitted the callipers and had a braket fabricated for the caliper conversion. The discs are a Quattro GMBH RS6+ and i think are 365mm, The pads cover the complete section of the disc, so you dont get lips created on the disc with pad wear.
I also have standard wheels.
Not sure about adapters / S4 geometry , and the RS6 discs. I do know that i did not have to do anything to adapt from RS4 discs to RS6+ discs.
Also : I have found that the cheapest way of replacing the pads is at a porsche dealer. much cheaper than getting from pagid.

[quattrokid1]

try again...

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... TQ:GB:1123