The real advantage the 312mm will have over 288's is the abbility to disperse heat build up which means less chance of brake fade but this can be easily cured with better performance pads, discs and brake fluid

Course from an asthetic point of view the 312's fill the wheels much better:thumbup:

They probably improve the feel and confidence too, but I'd agree that if both setups can lock the wheels, actual stopping distance won't change, at least on a single stop.

How often do you repeatedly go 0-60-0-60-0-60-0-60-0-60.... unless you are lewis hamilton doing his paper round:P

To be fair, I found the difference quite staggering in real life, normal driving situations. Controllable, non-locking, non-ABS braking is possible. I dont generally stop when I come up to roundabouts, I look ahead (if possible etc etc) and slow down to match my speed and then continue driving.

When driving on roads where the NSL is 70 mph and there are plenty of roundabouts, you can get pretty smelly brakes already after a few of them.

Also when having fun on a few of the backroads you can speed up hard where visibility is good, but there could be a cyclist round the bend. I would then speed up hard and slow down hard before loosing visibility so I could safely stop/slow down further as needed. The brakes on the PD100 estate would fade, 256 mm those ones, and on the vRS (when stock) they would too. I've never had fade with the 312mm ones.

That said if you cane it around on the track, I bet you can still get significantly better performance with larger brakes or better caliper designs.

They probably improve the feel and confidence too, but I'd agree that if both setups can lock the wheels, actual stopping distance won't change, at least on a single stop.

Agreed in principle, however, I have a feeling the 288s lock up easier. So the level of braking 'on the limit' before the calliper just grabs the disc, on 312s may be better. Just a theory there, someone knowledgeable technically on this may be a better bet on that topic though LOL

The DS2500s make a difference too

What are they? Do I have them?

What are they? Do I have them?

probably not,they are brake pads,break pads i have just been told are now £165 a set from my local parts shop,think i'll go back to jabba for them.

The only difference will be that the brakes will engage quicker which may help out by a metre or so but whatever it is negligable.

The real advantage the 312mm will have over 288's is the abbility to disperse heat build up which means less chance of brake fade but this can be easily cured with better performance pads, discs and brake fluid

Not negligable is you stop within a meter of the car infront just ONCE. As its just saved you alot more than they cost

Then your real advantage is just a bonus, like looks for most.

I did a little bit of playing yesterday on the same stretch of road and I can confirm that it definitely FEELS like you stop more quickly, and that the ABS doesn't seem to work quite as crazily (ie it feels more controlled). I've no idea why this might be. Maybe someone with a decent technical understanding of ABS systems could help, if they're reading.

The pads are still not properly matched to the discs yet (I think I swapped L and R discs around so they're a bit squeaky at the moment ) so I won't do a video until they are properly bedded in.

On another note I found this VERY interesting link whilst Briskoda was down over the weekend

Brake Myth #1

The most important quote of all in that page being...

If the front brakes develop more force at the tyre/road interface than 660 x 0.9G for a given pedal movement, then the front wheels will lock as the tyre starts to slide. Worse, the rear brakes will not yet be developing its maximum decelerative force of 440 x 0.9G - meaning that the total retardive force is less than 1100 x 0.9G. Thus the car is not going to decelerate as quickly as a perfectly balance braking system

Now I've done some thinking (dangerous) about this and have come to the following conclusion.

We have seemed to all agree that the limiting factor to how quickly we can stop is the quality of our tyres - ie the amount of grip between the road surface and the car. So if we've fitted bigger brakes that is in fact irrelevant with regards to braking torque front-rear balance when we're stopping as quickly as we can as the maximum deceleration generated by the front brakes is limited to exactly the same rate of change of velocity as when we had standard brakes - IF we are at the limit of tyre grip.

The time when the 312s are 'better' are in my opinion, and from reading stuff on t'interweb:

- Initial brake response time - the brake pedal doesn't travel as far to achieve the same braking force

- Ability to do repeated fast stops

- Ability to reduce speed from XXXmph as heat capacity is higher.

I understand from the quoted text above that when we're using say 70-80% of our available braking grip, the car probably doesn't stop as quickly as when we had a perfectly balanced braking system as the rears are doing even less than they normally would be in terms of utilising available grip on the rear wheels.

I guess the solution if you wanted to achieve perfect brake balance would be to upgrade the rear brakes' diameter by the same percentage as the fronts - but I think we would all agree that as the current items rust out anyway and seem to do very little, the gains in terms of performance would be far outweighed by the disadvantages of extra unsprung weight and extra cost.

i don't agree, obviously tyres are a limiting factor but to say they are the only factor in a single stop is simply stupid as your saying that if you have teeny little brakes that can lock the wheels once stamped on then even F1 brakes would make no difference.

If you can apply the brakes at full braking pressure immediately then in a single 60mph-0mph stop I don't think there will be any difference at all between "f1 brakes" and the normal tiny brakes that can lock the wheels, if the tyres are at the limit of available grip, because even if applied braking forces were greater, the car literally can not stop any quicker.

Fitting an air-brake is the only way to decrease stopping distances if the tyres are the weak point - which - in the case of them locking - they are.

Thing is, you DONT do the kind of braking that is right on the limit of your grip generally (well at least I don't, maybe I dont try hard enough..) I just want to slow down in a controlled and confident way. I remain convinced that the bite of the larger discs/pads combo is just so much more controllable, light braking force is instantly available, and you can vary the braking more easily.

On the Fabia the nose dive gives a very crappy feel of how fast you are slowing down vs feeling like you're lurching forward whilst the nose tucks down. Suspension tweaks help a lot with that. On the estate (PD100, stock, 256mm brakes) the amount of dive was distinctly less, and it felt more controlled. However post Ross doing the conversion, with 312mm brakes, there was *no* doubt braking was vastly improved in every way.

Is it worth it for you - that all depends on you

If you can apply the brakes at full braking pressure immediately then in a single 60mph-0mph stop I don't think there will be any difference at all between "f1 brakes" and the normal tiny brakes that can lock the wheels, if the tyres are at the limit of available grip, because even if applied braking forces were greater, the car literally can not stop any quicker.

Fitting an air-brake is the only way to decrease stopping distances if the tyres are the weak point - which - in the case of them locking - they are.

so how come i can stop quicker on my bike with the much better brakes than before yet i have no airbrake?

have you ever actually ridden or driven anything with proper high spec brakes?

not trying to sound condescending or anything but driving a normal car with normal brakes then a normal car with ever so slightly bigger normal brakes doesn't count as high spec

so how come i can stop quicker on my bike with the much better brakes than before yet i have no airbrake?

Well perhaps the tyres on your bike are much better than the tyres on the cars that I have driven (quite likely, given that it is the single most important component of a bike), and they are consequently not the limiting factor of how quickly youc an stop?

have you ever actually ridden or driven anything with proper high spec brakes

No, I haven't!

not trying to sound condescending or anything

You did, but I'll forgive you as it obviously isn't intentional

but driving a normal car with normal brakes then a normal car with ever so slightly bigger normal brakes doesn't count as high spec

OK then, let's end this here. I don't know the ins and outs of the science of this, I'm not a motorsport engineer (unfortunately) and as you say I haven't driven a wide enough range of vehicles to make a balanced decision. But I'm willing to bet you don't know all the answers either, and the answer probably lies somewhere inbetween our opinions .

*raises glass*

oh believe me i am fully aware of me not being a scientist or engineer due my general bodging and gun ho attitude and take on mechanicals

but all i am saying is with better brakes you seem to get a much greater degree of control throughout its entire action and they are far less on or off. personally i have found with poxy brakes you keep applying pressure and they slow you down a bit more and all of a sudden they lock up where as bigger/better brakes have a much more linear application of their power so you can get closer to teh tyres limit of grip before locking it if you know what i mean.

I do indeed, and perhaps that is where the advantage in the 312s lies.

I have noticed fairly obvious nose-diving with standard suspension and 312 items though

so how come i can stop quicker on my bike with the much better brakes than before yet i have no airbrake?

have you ever actually ridden or driven anything with proper high spec brakes?

not trying to sound condescending or anything but driving a normal car with normal brakes then a normal car with ever so slightly bigger normal brakes doesn't count as high spec

Thing is though a bike is a whole different kettle of fish. Being able to modulate is key to stopping a bike fast. If you lock the front wheel you either slide or go over the handle bars. That doesn't happen on a car with ABS.

Edit: The 105 makes nearly 1G under braking. What does the Fab vRS make?

Running Toyo 888 tyres, tarox Strada pads on tarox G88 discs (standard rear brakes) - my equipment went up to 1.5 g, and it was past that.

As i have said before, my observations on the 288 brakes is they ARE good brakes. They stop the car very quickly. The huge let down with them is lack of feel, lack of confidence, and jittery abs that jumps in when it feels like it, lengthening your stopping distance overall. Im not saying ABS is bad there, it's just over sensitive on the Fabia. I found with the 312 upgrade, the abs didnt kick in at all, except under the conditions it was designed to work under. The pedal feel was also much better, and pressure required to stop was lessened. My car would stop in half a car length from 30 mph with no abs activation when the brakes were nice and warm.

Right so to sum up.....

We are in agreement that from the point when the wheels are locked the difference between 288's v 312's is nothing as they no longer are doing anything it is the tyres doing all the work so to speak.

Secondly that the 312's offer an increased durability in terms of when fade occurs when 'on it'

thirdly bigger brakes look better as there is nothing worse than massive wheels with tiny little disc's behind them.

fourthly the guys with 288's still dont see any benefit yet the ones with 312's do even though as per point one then agree braking ability hasnt changed.

Fifthly It's the 'feel and control' of the 312's that keeps getting mentioned as being the most obvious difference in them which performance wise is actually not quantifiable.

Now lastly my point on this subject.

Take a look at the brakes on these two bikes

The first bike has 310mm discs running standard sliding 2 pot brakes with performance friction pads and a standard master cylinder.

The second bike also has 310mm discs but with radially mounted 4 pot calipers running the same pads but with a larger diameter brembo master cylinder.

Now if you exclude the fact they look different they are infact essentially the same bike. NOw ultimately when i raced these i could not brake any harder with the massively more powerful second set up over the first as the tyre would either wash out from under me or i would be pitched over the handlebars but yet the improved 'feel' i got from the second set up made my personal braking ability improve even though there were guys out there on the standard first set up who could still out brake me.

what it all boils down to is what you head perceives to be an improvement. How often do you hear people talking about how the induction kit they fitted last week gives them 2hp more and the car is soooo much faster. in reality it is fractions of seconds but the head says otherwise. I personally beleive the case with the brakes is the same. If you are happy and fully confident with the 288's then great but if you want for a bit more then the 312's are a relativly easy and cheap mod(in comparison to brembo or ap conversions) to give a try in search of the holy grail of what your head says is perfect.

The feel therefore, plus lack of fade (as I personally believe the brakes on that bike are probably both quite a lot better design as compared to the stock 288 mm ones on the vRS) allowed you to feel both more confident in ability to control, as well as consistently rely on, your brakes.

Good summary though

I still say the who 'brakes locked' thing is a diversion from the real argument because we all have ABS.

ABS appears to kick in more with the 288 setup as compared to the 312 setup, more sensitive somehow. It is hard to really explain in terms that are scientific to be fair, but it is a marked difference

ABS appears to kick in more with the 288 setup as compared to the 312 setup, more sensitive somehow. It is hard to really explain in terms that are scientific to be fair, but it is a marked difference

I agree - there's no way I would willingly go back to 288mm brakes. My wife, who likes her brakes, says they're ridiculously powerful now.

imagine spinning a wheel and stopping it with your index fingers, how hot would they get and how much pressure would you need to place through your fingers to stop the wheel.

Now do the same thing with your palms, no where near as much pressure needed and there isnt as much heat build up.

I upgraded from the OEM breaks as id experienced a few hairy moments and had no confidence in the breaks. My driving style doesnt involve stamping on the breaks every time i wont to stop. With the 312s i found that they suited my driving style much better.

I have recently upgraded again (got some 4 pot brembo callipers as a good price) to 323" and i find that with even small amounts of pressure the car slows down rapid. not totally used to them yet but even over the 312's i feel that my current setup is superior.

For me, its the lack of brake fade that makes them worth the money. And after all, they arnt a mega amount of money if you wait till your stock setup is ready to be replaced.

imagine spinning a wheel and stopping it with your index fingers, how hot would they get and how much pressure would you need to place through your fingers to stop the wheel.

More to the point, try stopping the spinning wheel with the palm of your hand in the middle of the wheel, and then at the edge of the wheel - at the edge of the wheel it's much easier.

Combining the increased 'torque' and the increased amount of surface area that is braking combined makes a massive difference.

I still say the who 'brakes locked' thing is a diversion from the real argument because we all have ABS.

Not really, because ABS basically enables you to brake as hard as the tyres will let you - ie for as long as the tyres have grip the brakes will be applied.

The better the tyres, the less time the ABS has to reduce brake pad pressure, so the faster you stop.

If the tyres aren't very good and ABS works overtime with 288 items, with 312items you won't stop any quicker because the tyres can only slow the car down at a particular rate.

As mentioned by others it seems the improvement in 312 items is in:

- Feel

- Control

- Heat capacity when stopping quickly, repeatedly.

There will also be a vast improvement in stopping distance in perfectly dry conditions with very good, grippy tyres that are operating a their optimum temperature - noone is doubting that. But for those among you who run budget tyres or who are testing on not-perfect surfaces or in the wet, I honestly don't think the 312s actually stop the car any faster than 288s in a one off stop.

I am still going to do the 312 video but it's been very wet recently and so there's been little point .

I was always of the 288 - 312 is only for feel & fade so no need on my Fabia persuasion. (but that's cuz I actually want 312 and can't afford.. so I'm jealous )

But having read through all the above posts it's now obvious to me that with the 312 you'll need less pressure for the equivalent amount of breaking allowing for far more control from the pedal.

And perhaps you can get more breaking in before the ABS kicks in because of this as the lower pressure makes the wheel slightly less inclined to lock as early?

I don't know anything really.. All I know now is I've just convinced myself I want 312's even more than before!