brake upgrade

[Guest]

Does anyone know the difference between standard 993 c2 calipers and 993 tt(big reds). Other than the colour is there anyway of telling by looking if for example they were the same colour?regards Ryan

 

[frogisland]

S4 vs Big Red; disc size, caliper surface area (piston size the same though as i recall)

this link will explain (hopefully) some

http://www.pelicanparts.com/MotorCity/wmv/brakes.htm

i also have a picture at this link of brake pads (albeit Big Red, S4, std 968)

http://img.photobucket.com/albums/v384/frogisland/993TT-030-Stdpads.jpg

...but your original question - it can be difficult to the 'untrained' eye, the S4 is a very similar to the Big Red if painted red (especially the late S4 caliper which does not have the raised lines/porsche script on the side)

JP

 

[Guest]

Cheers for the link ,i'll have a look at the pads aswell.Here is a picture of the calipers,there meant too be "big reds" but painted black.
http://img.photobucket.com/albums/v302/ryan_s3/Photo_Library___304.jpg
what do you think?thanks Ryan

 

[Guest]

here is a link too a picture of calipers off a 1994 993,which do you think theses are?
http://photobucket.com/albums/v302/ryan_s3/th_24_1_b.jpg

 

[eastendr]

993 Big reds on my 944T HERE

944 turbo250 / 928 S4 calipers HERE and HERE.

Both have the same piston size. The smaller calipers are for 304mm discs, the big reds for 322mm. The big reds also have a greater pad depth (58 vs 48mm) for a much larger swept area.

HTH

 

[Guest]

They both look identical to your big reds ,other than there black,there must be a way to tell?

 

[Guest]

i heard you could fit the 322mm discs and pads to the standard (smaller) porsche 993 caliper,i'm trying to get what i'm paying for.

 

[eastendr]

I would say that those are the larger calipers. They look original black, so are probably from a 928GTS.

Big reds are leading mount, big blacks are trailing mount, this should help you confirm ...

 

[Guest]

The calipers are two years old and were bought as a upgrade for a audi tt ,they have done 20,000 miles ,the guy ordered them black rather than red.How can you tell there the bigger ones eastendr?By the way how do you find your big reds?

After cafefully studying the pictures of the two calipers i can see the ones im getting are longer than the standard 993(s4's) so must be big reds,by the way where is the best place to get some replacement discs?

 

[eastendr]

Comparing the pictures closely between your black and my red calipers, they seem identical.

For discs, I use OEM 993TT drilled discs on the front, Zimmerman drilled discs on the rear. Try Eurocarparts.

I'm not over impressed by the current brake setup and may ultimately move up to an AP racing setup with 6 pots and 355mm or 378mm discs.

 

[Guest]

Another option is this new Brembo kit from Powerwerks
Apparently it leaves the big red kit standing and reasonably competatively priced

 

[wjk_glynn]

Can you describe the problems you're having with your brakes. E.g.:

* Feeling mushy
* Experiencing fade
* Can't get the wheels to lock (i.e. insufficient mechanical grip between the pads and disks)
* Wheels lock too easily
* Etc.

Karl.

 

[RUMS944]

I can sometimes lock the wheels, but if i have passengers or going at some speed i have trouble stopping. I bourght the car as a none runner and it had been sitting around for some time i spent some money on the brakes but it only just passed its mot. I've had two new callipers new pads and a master cylinder.

 

[John Sims]

I have I set of 250 Turbo callipers and disks off Beaky which might do you, but you will need radial mounts to fit them - or (better still) 250 hub assemblies.

I didn't have much confidence in the 220 callipers (small blacks) and found the 250's (medium blacks) to be much better.

Stainless steel hoses also give a great improvement and remove much of the mushiness of old rubber hoses.

 

[wizard]

Make sure you haven't got a bulge in the rubber lines near the assembly. It is possible the rubber has become very weak with age an can reduce the amount of pressure passed to the caliper.

 

[Neil Haughey]

ORIGINAL: RUMS944

I was wondering if it's worth just getting groved or drilled discs and better pads and hoses?

Pads with a higher coefficient of friction will result in more stopping power for less effort but these may require warming up on the track to work properly. Biggest problem that ppl experience with the stock brakes is that they overheat very easilly on track days. IMHO fresh fluid and a set of cooling ducts would be the first port of call.

On my own car I have x-drilled disks, ducts, uprated pads, SS braided hoses and ATE blue fluid. It still takes one hell of a lot of effort to get the ABS to come on when on the track with warmed up tyres, but on the road it is in general pretty easy.

ISTR the main difference with the setup on the late turbos is much larger pads.

 

[random hero]

ORIGINAL: wizard

Make sure you haven't got a bulge in the rubber lines near the assembly. It is possible the rubber has become very weak with age an can reduce the amount of pressure passed to the caliper.

This happened on my car,i tried a new servo/master cylinder/new fliud and new brake lines and it turned out to be a bulging rubber hose on the back axle where you cant see it !!!

 

[John Sims]

ORIGINAL: Neil Haughey

.....ISTR the main difference with the setup on the late turbos is much larger pads.

No the disks are larger diameter and thicker (32mm) and the vanes within the disks are curved so as to suck air through the disk.

The callipers and pistons are larger and the bolt holes are parallel to the disk not perpendicular to the face.

 

[Neil Haughey]

True but isn't the biggest difference the pad size which ISTR has something like 60% more surface area.

 

[RUMS944]

The rubber lines from what i can remember look in good condition but i was always going to change to stainless steel.
Dose the same hose fit the different callipers?

Hi John i would be interested in the 250 callipers and disks you have ( ill email you).

Where and how much can i get the radial mounts from?


Are there any other benifits from fitting the 250 hubs?

And one more, where do you get the cooling ducts from. Are they ones that replace the fog lights in the bumper?

Thanks for the advice so far.