Dave_Bayern
Slipping at 3.5Krpm
As some of you know I've been doing some brake investigations and I think I've pretty much found the best setup for A3/S3's.
I've spent a LOT of money to finally come to a brake setup I think is more than adequate, so far I have tried:
Discs:
Audi OEM Discs
EBC Turbo Groove Discs
Mintex
Zimmerman Solid
Black Diamond Grooved
ATE Power Discs
Pads:
OEM (Textar)
EBC Green Stuff
EBC Red Stuff
EBC Yellow Stuff
Pagid FR
Mintex Extreme
Ferodo DS2500
Ferodo DS3000
There may actually be more, I cant remember it all, I've had a lot!
I have the standard 312mm setup in regards to calipers, and my car is probably 150-200kg lighter than you guys, but the following info is still very relevant due to the power I am running.
Lets start with the actual braking hardware, and compare Brembos to the standard 312mm brakes.
The Brembo GT two piece calipers are a similar weight (although are lighter) than the stock 312mm calipers. They are also 4 piston calipers and thus better/more efficient than the sliding caliper (equivalent to 2 pistons) standard caliper.
However, there is one major downside to the Brembo GT system = weight. The GT discs are 323mmx28mm compared to the 312mmx25mm standard discs.
The Brembo GT discs weigh a LOT, I havent actually weighed them for exact figures but holding them up side by side there is a huge difference, probably somewhere in the region of 1.5-2kg. (Much wider, taller discs on the Brembo is a lot of extra metal)
The big disadvantage there is in unsprung weight, as adding 1kg of extra unsprung weight is the equivalent of adding 6kg of sprung weight, plus it is detrimental to handling/cornering/suspension.
Aside from this Brembo discs are pretty famous for warping so cost is a factor considering ideally you should throw away the drilled discs and buy Leon Cupra solids.
That said, they brake very very well even on standard pads
However, for this I am going to discount them on the basis that they arent needed for anything but big turbos, they cost a lot to buy, they cost a lot to replace discs and they are detrimental to the handling of your car.
So, the cheapest and generally most sensible choice is
to retain the standard 312m setup and make it the best it can be.
The first thing you need to do is change your fluid. After only one year your fluid can take on as much water as 3%, which actually translates to 15-25% less braking power!!!!
The type of fluid is important too, as DOT5.1 fluid with 3% water still performs as well as brand new DOT3 fluid.
So you ideally want to use DOT5.1 as its more resistant to water, and has higher and lower boiling points.
This is one of the things that makes brakes fade, boiling fluid, the fluid boils due to heat and the boiling produces steam, which then cools to air and water, which then gets into the system making for a spongy brake pedal.
So you also need to try and use a fluid which has the highest possible wet and dry boiling points.
You have three choices:
Halfords DOT5.1 - Cheap with a trade card (3 per bottle)
Motul RBF600 - 11 per bottle and excellent properties
Castrol SRF - The best of the lot but 40 per bottle.
So if you dont mind changing it often and have a Halfords trade card, the Halfords stuff is great.
Castrol is VERY expensive so that leaves Motul RBF600. It is actually classified as a DOT4, but everything except viscosity at 40 degrees is better than DOT5.1 and its cheap at around 10-12 a bottle so well worth using.
So first thing, make sure you fluid is new, and good quality, such as Motul RBF600 Factory line.
Right, now onto discs, these are less complicated, all discs are is a friction surface for the pads to act against, so they are the least important parts of a setup.
For heat dissipation and price, any solid discs such as Zimmerman/Mintex whatever would be great, and cheap at under 40 pound each.
Grooved discs have slightly more cooling area than solids due to more surface area and they also serve to slightly deglaze the pads (although this is less important when using better pads but I'll come to that).
Drilled discs are the devils work, they are actually nothing to do with heat dissipation and all to do with reducing weight, which is why you see drilled discs on cars with huge brake discs, its to reduce the unsprung weight. However, on cheap discs it also provides a heat concentration point and it tends to warp and crack the discs.
Another important factor is how the discs are treated, their carbon content etc, but the idea is, the more you pay for a set, the longer they will last.
Black Diamonds are a good example of this, they last forever and a day, where the BD had 10K miles and were 1mm down from new, the Zimmermans had 5K and were 1mm down from new.
So, fluid is very important, discs less so, now onto pads.
Pads these days vary in quality a huge amount, right from 30 pound OEM pads to 160 pound DS3000s.
The most important thing to remember with pads is, you get what you pay for.
ALL EBC pads are rubbish, utter, utter rubbish and I wouldnt wish them on anyone. They have slightly better properties than OEM when warm, but otherwise are way worse. (With the exception of yellows, which are better than OEM at all times but awful compared to other track pads)
OEM, Pagid FR and Textar pads all seem to be very very similar, or at least made to similar specs. Pagids again have better fade resistance than OEM but the same friction properties in general. They would be a good choice if only wanting something cheap but better than OEM.
Mintex Extreme are very good, they are far superior than OEM from Cold, have great, repeatable friction and it takes some work to get them to fade. They are however, discontinued.
Now onto the Ferodos. These are the pads to end all pads. There are a few better for certain applications but very little will touch these two for road and track use.
Firstly Ferodo DS2500s. They have better bite from cold than OEM, better bite hot, never EVER fade and have a really consistent friction co-efficient of 0.48 from cold right to about 500 degrees.
These make OEM pads look like you've been using compacted paper as pads, they are a world apart.
They cost about 130 the pair and are well worth the money.
Now until about a week ago, I would have ended there, but as it happens Bill at Badger5 supplied me with some Ferodo DS3000s and I fitted them the day they arrived.
The difference between DS2500 and DS3000 is like the difference between OEM and DS2500 - its HUGE.
DS3000 are 160 the pair, but I absolutely will never use DS2500s again.
The friction co-efficient of the DS3000s is better (0.62) and again is the same, repeatable throught the temperature range. Basically your fluid will boil before the pads suffer fade, they are THAT good!
They do suffer badly from squeal at low speeds and when cold, they also need a little bit of heat to work (they are race pads) but they absolutely stop the car dead.
Prawn from this forum drove my car yesterday, we have pretty much the same car but he has Black Diamond discs and Ferodo DS2500 pads. He got out of my car and proclaimed that they are 'shockingly' good, and hes right.
The tyres loose traction if you brake too hard with DS3000s (Goodyear Eagle F1s) and on continued braking they just keep braking exactly the same regardless of heat, doing some country back roads they were the same from start to finish.
To finish off, the other thing you should look at is replacing your brake hoses if you have a lot of miles on them. The standard Audi hoses are internally braided but also very large bore, so replacing them with small bore braided hoses means less effort - same braking = better pedal feel.
So, for the BEST system for 99% of S3s you would need:
Braided hoses
Motul RBF600 Fluid
Discs of your choice (ATE Powerdiscs for me)
Ferodo DS3000 pads.
P.S For the rears, they do very little braking so even OEM pads will be fine, and OEM or Brembo Max discs (Solids).
I've spent a LOT of money to finally come to a brake setup I think is more than adequate, so far I have tried:
Discs:
Audi OEM Discs
EBC Turbo Groove Discs
Mintex
Zimmerman Solid
Black Diamond Grooved
ATE Power Discs
Pads:
OEM (Textar)
EBC Green Stuff
EBC Red Stuff
EBC Yellow Stuff
Pagid FR
Mintex Extreme
Ferodo DS2500
Ferodo DS3000
There may actually be more, I cant remember it all, I've had a lot!
I have the standard 312mm setup in regards to calipers, and my car is probably 150-200kg lighter than you guys, but the following info is still very relevant due to the power I am running.
Lets start with the actual braking hardware, and compare Brembos to the standard 312mm brakes.
The Brembo GT two piece calipers are a similar weight (although are lighter) than the stock 312mm calipers. They are also 4 piston calipers and thus better/more efficient than the sliding caliper (equivalent to 2 pistons) standard caliper.
However, there is one major downside to the Brembo GT system = weight. The GT discs are 323mmx28mm compared to the 312mmx25mm standard discs.
The Brembo GT discs weigh a LOT, I havent actually weighed them for exact figures but holding them up side by side there is a huge difference, probably somewhere in the region of 1.5-2kg. (Much wider, taller discs on the Brembo is a lot of extra metal)
The big disadvantage there is in unsprung weight, as adding 1kg of extra unsprung weight is the equivalent of adding 6kg of sprung weight, plus it is detrimental to handling/cornering/suspension.
Aside from this Brembo discs are pretty famous for warping so cost is a factor considering ideally you should throw away the drilled discs and buy Leon Cupra solids.
That said, they brake very very well even on standard pads
However, for this I am going to discount them on the basis that they arent needed for anything but big turbos, they cost a lot to buy, they cost a lot to replace discs and they are detrimental to the handling of your car.
So, the cheapest and generally most sensible choice is
to retain the standard 312m setup and make it the best it can be.
The first thing you need to do is change your fluid. After only one year your fluid can take on as much water as 3%, which actually translates to 15-25% less braking power!!!!
The type of fluid is important too, as DOT5.1 fluid with 3% water still performs as well as brand new DOT3 fluid.
So you ideally want to use DOT5.1 as its more resistant to water, and has higher and lower boiling points.
This is one of the things that makes brakes fade, boiling fluid, the fluid boils due to heat and the boiling produces steam, which then cools to air and water, which then gets into the system making for a spongy brake pedal.
So you also need to try and use a fluid which has the highest possible wet and dry boiling points.
You have three choices:
Halfords DOT5.1 - Cheap with a trade card (3 per bottle)
Motul RBF600 - 11 per bottle and excellent properties
Castrol SRF - The best of the lot but 40 per bottle.
So if you dont mind changing it often and have a Halfords trade card, the Halfords stuff is great.
Castrol is VERY expensive so that leaves Motul RBF600. It is actually classified as a DOT4, but everything except viscosity at 40 degrees is better than DOT5.1 and its cheap at around 10-12 a bottle so well worth using.
So first thing, make sure you fluid is new, and good quality, such as Motul RBF600 Factory line.
Right, now onto discs, these are less complicated, all discs are is a friction surface for the pads to act against, so they are the least important parts of a setup.
For heat dissipation and price, any solid discs such as Zimmerman/Mintex whatever would be great, and cheap at under 40 pound each.
Grooved discs have slightly more cooling area than solids due to more surface area and they also serve to slightly deglaze the pads (although this is less important when using better pads but I'll come to that).
Drilled discs are the devils work, they are actually nothing to do with heat dissipation and all to do with reducing weight, which is why you see drilled discs on cars with huge brake discs, its to reduce the unsprung weight. However, on cheap discs it also provides a heat concentration point and it tends to warp and crack the discs.
Another important factor is how the discs are treated, their carbon content etc, but the idea is, the more you pay for a set, the longer they will last.
Black Diamonds are a good example of this, they last forever and a day, where the BD had 10K miles and were 1mm down from new, the Zimmermans had 5K and were 1mm down from new.
So, fluid is very important, discs less so, now onto pads.
Pads these days vary in quality a huge amount, right from 30 pound OEM pads to 160 pound DS3000s.
The most important thing to remember with pads is, you get what you pay for.
ALL EBC pads are rubbish, utter, utter rubbish and I wouldnt wish them on anyone. They have slightly better properties than OEM when warm, but otherwise are way worse. (With the exception of yellows, which are better than OEM at all times but awful compared to other track pads)
OEM, Pagid FR and Textar pads all seem to be very very similar, or at least made to similar specs. Pagids again have better fade resistance than OEM but the same friction properties in general. They would be a good choice if only wanting something cheap but better than OEM.
Mintex Extreme are very good, they are far superior than OEM from Cold, have great, repeatable friction and it takes some work to get them to fade. They are however, discontinued.
Now onto the Ferodos. These are the pads to end all pads. There are a few better for certain applications but very little will touch these two for road and track use.
Firstly Ferodo DS2500s. They have better bite from cold than OEM, better bite hot, never EVER fade and have a really consistent friction co-efficient of 0.48 from cold right to about 500 degrees.
These make OEM pads look like you've been using compacted paper as pads, they are a world apart.
They cost about 130 the pair and are well worth the money.
Now until about a week ago, I would have ended there, but as it happens Bill at Badger5 supplied me with some Ferodo DS3000s and I fitted them the day they arrived.
The difference between DS2500 and DS3000 is like the difference between OEM and DS2500 - its HUGE.
DS3000 are 160 the pair, but I absolutely will never use DS2500s again.
The friction co-efficient of the DS3000s is better (0.62) and again is the same, repeatable throught the temperature range. Basically your fluid will boil before the pads suffer fade, they are THAT good!
They do suffer badly from squeal at low speeds and when cold, they also need a little bit of heat to work (they are race pads) but they absolutely stop the car dead.
Prawn from this forum drove my car yesterday, we have pretty much the same car but he has Black Diamond discs and Ferodo DS2500 pads. He got out of my car and proclaimed that they are 'shockingly' good, and hes right.
The tyres loose traction if you brake too hard with DS3000s (Goodyear Eagle F1s) and on continued braking they just keep braking exactly the same regardless of heat, doing some country back roads they were the same from start to finish.
To finish off, the other thing you should look at is replacing your brake hoses if you have a lot of miles on them. The standard Audi hoses are internally braided but also very large bore, so replacing them with small bore braided hoses means less effort - same braking = better pedal feel.
So, for the BEST system for 99% of S3s you would need:
Braided hoses
Motul RBF600 Fluid
Discs of your choice (ATE Powerdiscs for me)
Ferodo DS3000 pads.
P.S For the rears, they do very little braking so even OEM pads will be fine, and OEM or Brembo Max discs (Solids).