Braking
GTA's are fitted with 259mm discs all round as standard. 20mm thickness on early cars, soon upgraded to 22mm on later cars to prevent warping or cracking. There is absolutely no difference between the brakes on Turbo and Normally aspirated cars (this is a common misconception). ABS was also available as an option for both models. Unfortunately the near £2000 price tag put off most purchasers and it was only fitted to a handful of cars. You can tell if your car has ABS from the additional warning light on the dash. To double check have a look behind the right hand front wing just in front of the wheel. A large ABS distribution block suspended with hydraulic pipes is a sure sign! The additional ECU or 'brain' is fitted behind a bulge in the front compartment liner, again to the right hand side. ABS was standard on all Le Mans cars.
The brakes work well with standard cars, but those of you that have 'tweeked' your engine a little will soon want to upgrade. Direct replacement EBC or ATE drilled or grooved discs are a popular choice. Unfortunately both are only available in 20mm thickness which reverts the car to early spec. However they are much more efficient than standard discs worn below their minimum thickness.
EBC Greenstuff are a popular pad upgrade for fast road use. Redstuff are good for the occasional trackday.
Replacing the flexible hoses with BF Goodrich or similar braided brake-line kits is also a worthwhile upgrade and improves pedal feel. However some MOT stations will fail your car if these are fitted. You have been warned! BF Goodrich hoses are now also available in a range of colours with a wipe clean vinyl finish.
However if you really want to give your GTA some serious stopping power the only real option is larger discs and callipers. A610's were fitted with larger 300mm discs and ABS from the factory as standard. You can fit these to a GTA but you will need to change the hubs as A610 discs are 5 stud fitment. In addition the callipers are located in a slightly different position. This can prove to be a costly and complex conversion. In addition the A610, along with the GTA, was still only fitted with inefficient sliding single piston callipers front and rear. For a real improvement you will need to upgrade to 4 piston ('4 pot') callipers. These operate directly on the pads on both sides of the disc and distribute the braking force more evenly over the surface of the pad. Many French tuning firms offer big calliper kits for the GTA although they are often extremely expensive. Click on the links above for details of the new UK alternatives.