8 replies to this topic

[mic]

so whats so good about em?

[Grayedout]

Because they can lose heat better which is one of the keys to good braking performance.

[mic]

yea but so do drilled?

[Sprocket]

Nothing really good about them.

They add weight to the unsprung mass

They make the wheels stick out further

Are over the top ( standard solid discs are adequate)

[Dan]

yea but so do drilled?

No they do not. Common mistake. Drilled holes in discs are there only to allow the build up of gas that can form under the pad during heavy braking to escape because otherwise the pad floats on the gas like a hovercraft and you loose braking efficiency. This is essentially the real cause of brake fade. Grooves on discs are there only to clean crud off the face of the pad. Neither of these add any serious cooling capacity to the disc. Vented discs have a large air space inside them and a from of turbine designed to draw air into the space and force it to flow through the disc while it is turning, actively cooling it.

[*DJH*]

yea but so do drilled?

No they do not. Common mistake. Drilled holes in discs are there only to allow the build up of gas that can form under the pad during heavy braking to escape because otherwise the pad floats on the gas like a hovercraft and you loose braking efficiency. This is essentially the real cause of brake fade. Grooves on discs are there only to clean crud off the face of the pad. Neither of these add any serious cooling capacity to the disc. Vented discs have a large air space inside them and a from of turbine designed to draw air into the space and force it to flow through the disc while it is turning, actively cooling it.

Am i right in saying Dan that you can buy 'vented, cross drilled and grooved' disks, i'm pretty sure i've seen this on an ex-sierra cosworth touring car.

[Road Runner]

You can but you must remember the hole goes into the vents thus allowing the pressure to diapate

[*DJH*]

That's what i thought.

[taffy1967]

Standard discs are fine for road going Minis, but I've found EBC Greenstuff has helped prevent brake fade and I get less brake dust on my alloys too.