Bigger Brakes = Better? (Road Use)

Being a numpty when it comes to engineering/physics type stuff, can someone please explain the following to me.

If I have standard brakes, and yoko AO48’s, with the standard Exige ABS setup, and it takes X metres to stop from 100mph in the dry pressing as hard as possible (i.e. the ABS kicks in). Then what advantage is a bigger, more powerful brake set-up?

Ignore any resistance to fade and track use etc. For this one-off test on a road would a brake upgrade allow the car to stop in a shorter distance? Because isn’t the adhesion governed by the tyres, therefore more powerful brakes would just reach the limit of adhesion quicker… so essentially you would stop in the same distance (as the ABS would kick in)?

You’re right. Brakes don’t stop cars, tires do.


See here for more about the physics and here for an explanation of how things can be made worse by fitting big brakes without considering the system as a whole.

Bob, another element to throw in to the equation is the momentum you have at high speed. It is massively difficult to lock a wheel at high speed as the car is trying to stop the wheels from locking. Which is why the correct technique is to brake to the maximum initially and reduce the pressure as the car slows so to stop wheel locking. Increased brakes will stop the car quicker at high speed where the ABS is irrevelant as it’s never going to come in. A better brakes set-up may also give you more feel and therefore improve your control and confidence in them.

Its probably true though that an improved disk/pad package won’t be optimised for the std ABS set-up.

To be honest, having experienced Gavin Kershaw’s braking at Donnington I very much doubt many people are making the best use of what they have. The S2 can REALLY stop, even on the standard pads. That said, it will cost you a lot in pads.

Ian

That said, it will cost you a lot in pads.

Ian

Not if you just use Andy D’s

Really? Are you seeing an improvement in braking and pad longevity (he asks excitedly have just fitted his!)?

Ian

I think Steve was referring to the fact that Andy’s pads (RS14’s) got fiited to the Exige-S Gav was driving at Donny after he had obliterated the set on the car (and had not bought any replacements).

Unless you were just being ironic

Ah yes, that would make sense (he says slightly deflated that his friend has just pulled the preverbal “could it really be this good!” rug from under his feet).

Just brake in the dry without the ABS cutting in you will stop a good few meters sooner.

Bob

I read the Stop-Tech description but not sure i spent enough time understanding it.

Anyway, put simply… I thought ABS stopped the wheel locking ? so if i’m right then without the pilot using Threshold braking (i.e. stabbing the pedal as hard as you can just to the point before it locks and keeping it there by easing off appropriately as you slow down) wouldn’t a bigger brake get you from speed X mph to 0 mph quicker in less distance and hence even with ABS, bigger brakes will be an advantage ? … assuming you want to stop in less distance over standard

completely ignoring the Stop-Tech advice of course, cause i’m not sure I agree with it all.