Rear brake upgrade

[h100vw]

The a1rms are another level of sharp now I bedded them in. Like hitting a wall.

[kaanage]

Bigger brakes are usually to reduce fade, to brake more consistently , not necessarily brake harder (although larger brakes would probably allow you to stop quicker from a very high speed, say 200++?)

The larger brakes will only stop you faster from very high speed if the brakes are getting so hot that they fade out during the braking period. The brakes would need to be truly undersized for this to happen.

More than likely, stock or larger brakes would stop in the same distance on the first stop from 100kph, but by the 10th stop, I know which one id want

While this is definitely true, if you are getting to this situation on public roads, then you need to reevaluate your driving technique. I have never been left behind on a cruise even when others have cooked their brakes on the same cruise.

Even on track, brakes are one of the least important components in achieving ultimate lap times - I got within a second of my best lap time at Sandown (which is very hard on the brakes) after air got into the system and the pedal was almost going to the floor. It's unnerving but as long as the brakes still work you don't actually go that much slower.

If you are RACING (as opposed to doing timed laps, happy laps, hill climbs), then braking becomes much more important for the TACTICAL advantage when passing or preventing a pass but as long as they don't fade right out, the effect on ultimate lap time is actually quite small since you just don't spend that much time braking.

I can assure you my stock sized brakes don't compare to Gav or Seans bigger brake setups. I find the Remsa and DBA T2 rotor combo a good upgrade over the stock rotors and pads, but they simply can't stop the car anywhere near as quick as Gav or Seans regardless of if its the 1st or 10th time.

If that's the case, then you either have tyres that are quite a step down from theirs or there is an issue with your brakes. While the Remsa's won't give the bite of more aggressive pads (once they are properly bedded in and warmed up), you should still be able to reach the limits of adhesion quite easily. I've used both on the track with my GTi front brakes and the Remsa's still pull the car up just as well but it takes more pedal pressure (and the pads show more wear).

The a1rms are another level of sharp now I bedded them in. Like hitting a wall.

Yes It's very noticeable how much harder they bite once bedded in properly with the multi crash stop procedure. The big problem I have found with them on road ('cos I drive for economy) is that without consistent hard driving, they will go green again after a while which chews out the rotors and squeals as well as not biting as hard.

[seangti]

I absolutely understand your position, it all comes down to the lowest common denominator, which is typically the tyre grip. The difference in lap times between my silver car and red car also supports your position that brakes don't save significant time on the track.

With all that said, when I'm coming into a hair pin at ~190kph with an apex speed of ~80kph, it's nice to know that when I go for the brakes, I'm going to have a pedal, it's hugely confidence inspiring. I guess it's about feel and confidence. There ability to slow you down immediately as you apply at that high speed is much greater than I've experienced on a small rotor, part of it is purely down to leverage too.

On a 288mm set-up with Remsa (not a track pad), I was exceeding their performance window. I couldn't put the car on it's nose on successive laps. On the 312mm with Remsa, they lasted and felt better, great when new, but were deteriorating in feel after track time, or particularly if I'd overcommitted to a corner, the pedal took half a lap to come back. The A1RM's are operating in their designed temperature window (at the lower end according to my rotor temps) and maintain feel for the drive home. Perhaps a track suitable pad on the 288's would be suitable, though you also can only get a DBA T2 rotor, not a T3... relevant or not I don't really know. I do get the occasional squeal with the A1RM's when cold, but feel is still fine.

Though we've probably hijacked the hell out of the OP's thread, sorry dude.

In short, IMO, it's a waste of money if you aren't utilizing the upgrade, or currently reaching limits of the factory set-up, which, with good fluid and pads, can be quite effective to run hard.

[sambb]

Unless fade is singularly your biggest problem I dont really see the point of having braking power way beyond what your tyres can handle or the point at which ABS will kick in. eg time attack cars pull up from F1 speeds on tiny little brakes. Fade avoidance over time is not their enemy but unecessarily high rotating weight and unsprung weight is. They certainly have the braking power to do it though even with relatively small brakes.
Why shell out for the lightest rims and then fill them with excess braking weight. Then you're still at square one in the unsprung weight department and end up with arguably more or less the same braking power especially if your on more streety track tyres.

[rgvlee]

I'm more thinking of doing it 'because I can'

[seangti]

I'm more thinking of doing it 'because I can'

lol, no further justification is required.

Make it happen

[sambb]

then we did well and truly hijack. sorry mate.

[rgvlee]

Well they were lot closer than I thought, trackday yesterday finished them off.
Will try to source on Monday otherwise I'll have to throw stock gear on.
Chasing some early audi tt leads.
There is a thread on another forum listing rotor sizes for the various models that fit mk4 golfs, I'll post up the details later interesting reading.

[kaanage]

Sorry to all who may have thought i was saying a bbk is a waste of money. It does have real benefits in the right circumstances but I'm trying to put the focus on where these real benefits are as opposed to what some people may assume without thinking through the underlying physical factors and limitations.

Rgvlee, that's as good a reason for the upgrade as many of the things we do. Eg last night I used a trim sealant on my tyres and the nut caps.

[Martin]

On a Polo there may not be enough rubber on the road to gain a lot more braking but I would still expect more capable braking with lower pedal pressure
On my Octavia I have 6 piston calipers and 357mm floating rotors - with good rubber ( Goodyear F1A1 225/40/18 ) it certainly brakes significantly harder than a standard Octavia
(In order to get that extra braking I had to get into VCDS and set the anti lock braking to low/late because the car could now brake harder/faster than the onboard computers though was possible)
Around town and during rush hour driving it's less fatiguing because much less brake pressure is required - yet modulation control is still good

[rgvlee]

This is the thread I was talking about

The Mk4 Brake Upgrade - Sizes/Info

Heres all the brake sizes on the VAG range, and what they are fitted to as standard.

VW Golf R32 | Audi TT 3.2 Quattro
The Front brakes are 334mm x 32mm Vented 2-piece Discs, Twin piston(32mm/42mm) calipers
The Rear brakes are 256mm x 22mm Vented Discs, 38mm Lucas singles

Seat Leon Cupra R

The Front brakes are 323mm x 28mm Vented (grooved/drilled option) discs with 4 piston(34/38mm) Brembo calipers
The rear brakes are 256mm x 22mm Vented , with 38m Lucas single piston calipers

Audi TT-Quattro (225hp) | VW Golf anniversary | Golf GTI AUQ | Skodá Octavia VRS | VW Golf V5 170 | VW Golf V6 4 Motion
The Front brakes are 312mm x 25mm Vented Discs, 54mm ATE single piston calipers
The Rear brakes are 256mm x 22mm Vented Discs, 38mm Lucas single Piston calipers

Audi TT (180hp)
The Front brakes are 312mm x 25mm Vented Discs, 54mm ATE single piston calipers
The Rear brakes are 232mm x 9mm Solid Discs,

Golf GTI 1.8T | Golf 130/150 TDI | Golf V5 150 | Seat Leon 130/150 TDI and 20VT
The Front brakes are 288mm x 25mm Vented Discs, 54mm ATE single piston calipers
The Rear brakes are 232mm x 9mm Solid Discs

Golf 2.0 8v | 1.8 | TDI 115 | TDI 110 | TDI 100 | TDI 90
The Front brakes are 280mm x 22mm Vented Discs, Single piston calipers, caliper carrier integrated into hub (FS III's)
The Rear brakes are 232mm x 9mm Solid discs

Golf 1.4 16V | Golf 1.6 16v | Golf 1.6 8v | SDI
The Front brakes are 256mm x 22mm Vented Discs, single piston calipers, carriers integrated into hub (FS III's)
The Rear brakes are 232mm x 9mm Solid Discs

I've managed to locate a front and rear set off a 99 TT quattro but unsure if they'd fit. I think that's the 225hp model.

[rgvlee]

OK I've managed to find a set of calipers off a 2000 S3 as well.
What's the best way to ensure any of these will fit? They are all on the otherside of the country so I can't pop in an check before I hand over coin.

[h100vw]

They will fit Lee. You need the calipers and brackets.

[rgvlee]

The 2000 S3
or 99 TT quattro?
or Both?

Both are about the same price.
And yeah I'm onto the calipers and carriers.

When ordering rotors/pads, do you just order them for a 2000 S3?

[h100vw]

The 2000 S3
or 99 TT quattro?
or Both?

Both are about the same price.
And yeah I'm onto the calipers and carriers.

When ordering rotors/pads, do you just order them for a 2000 S3?

They are both the same Lee.

If you get pads from GSL/Brakes Direct Matt knows what you need. Otherwise, correct S3 pads.

Gavin