Cooling advantage of drilled disks?

[djones]

What would you guess the cooling advantage is of running drilled disks?

I've been thinking and can't see how they are really an advantage. I mean, they might have a few % more surface area (??) but that surely wont help that much?

[czt]

I've not really looked into it, but my understanding is that drilled discs reduced gas build up between pad and disc face and hence improve performance that way.

[ISLAMATRON]

dont do it, stick with full blanks

there is no performance enhancement, but a big loss in reliability

[Shrek]

I've not really looked into it, but my understanding is that drilled discs reduced gas build up between pad and disc face and hence improve performance that way.

i know they build slotted discs to keep the fins free to pull air out of the center, but still get rid of the gas

[djones]

Looking on Brembo's site they say drilled is for cooling and in reference to the slotted (grooved) disks they dont mention cooling and just getting rid of gas if I remember correctly.

As the holes presumably do this then grooved seem pointless.

If the cooling advantage is minimal then I guess they are pointless.

But.... porsche etc fit drilled so maybe there is more to it?

[safeaschuck]

Better for cooling in this order:
grooved
drilled
grooved and drilled
also progressivly louder and eat up brake pads quicker so less suitable for road car applications.
Assume it would affect the strength of cabon ceramic discs more severely than steel.
Both methods are for clearing (hot) gas as far as I understand.

[Trying to go minimal with the posting ]

[Belatti]

I know a brake disc supplier here that receives the "blank" discs directly from Brembo and makes the groves himself. He has a brake test bench and has a lot of experience developing the groves shapes.

He told me its incredible how the shapes of the groves can change braking performance and that there is a specific design that works best for each application, like Rally, Touring car or Formulas. It has a lot to do with cooling, dirt, wheel rims, and mainly the brake system design "philosophy", that is how you transmit the force: with high fluid pressure and small diameters in pumps and discs or lower fluid pressure and bigger bores.

It would be nice to check out different F1 carbon brake discs pics and compare what are teams using and what did they used in the past.

[The_Man]

I've been thinking and can't see how they are really an advantage. I mean, they might have a few % more surface area (??) but that surely wont help that much?

It is not the little % increase in surface area that will cause the cooling it is the fact that the hole will allow passage of air and that will lead to convective cooling. There is almost always a pressure difference on either side of the brake disk.

It is a good source for reject heat from within the material rather than waiting for it to come towards the surface. It can be critical specially in large disks, to control temperature concentration at a single point on the disk.

[RH1300S]

What would you guess the cooling advantage is of running drilled disks?

I've been thinking and can't see how they are really an advantage. I mean, they might have a few % more surface area (??) but that surely wont help that much?

What are you using the car for?

If it is road/track day - are you really getting a problem with overheated discs?

Are the discs vented or solid?

TBH - for most cars in road use (and probably track day use) a good solid disc and good pad combination will work well and reliably.

I have used slotted discs to good effect - but honestly would be hard pressed to say if they were better than the plain vented discs.

You do hear of cracks developing from holes in discs - so consider you service life

[alexbarwell]

Yep, depends on application, look at some of the AP racing disks and you'll see C shaped slots cut into the disk. Higher power turbo cars fitted with thicker and vented discs to deal with the extra power to be handled, but it is very dependent on the power levels as you want the brakes working in the optimum temperature range. Slots sweep the pad faces, normally at an angle. Dimpling is also done on some discs rather than drilling completely through.

[autogyro]

Why throw away all that energy with crude friction?
It is little better than putting your feet on the road to slow down.

Use a brake generator on each wheel, or the front wheels and the rear in the gearbox. Use as much of the energy stored into batteries and flywheel storage devices as possible, the rest from heavy braking direct into a heat storage sump in the chassis.
Then recover from the sump by converting the heat back to electrical storage.
(Heat sump storage would also be useful for car heating in road EVs.)
It will come soon.

[djones]

The reason I ask is we are taking a TT to the Nurburgring this year and the standard brakes are pathetic to say the least.

OEM disks and pads they fade after about 5 100-40 MPH stops.

We can go 'track' pads such as the Ferodo DS3000 which will make a huge difference but we were wondering if it was worth swapping the OEM disks for Brembo Drilled disks (same diameter etc, just drilled).

Brake fluid will be changed for Motul RBF600.

[RH1300S]

The reason I ask is we are taking a TT to the Nurburgring this year and the standard brakes are pathetic to say the least.

OEM disks and pads they fade after about 5 100-40 MPH stops.

We can go 'track' pads such as the Ferodo DS3000 which will make a huge difference but we were wondering if it was worth swapping the OEM disks for Brembo Drilled disks (same diameter etc, just drilled).

Brake fluid will be changed for Motul RBF600.

Short answer pads and fluid for sure. Discs will probably help, but you have done the important stuff with the pads and fluid. I would still wonder whether you would notice the drilled discs over standard ones, but fitting Brembo is a good idea anyway (quality stuff).

Ferodo pads are savage on discs, but they give you incredible stopping and great feel also pretty much fade free. I would say a good choice for the 'Ring.

Good plan going to the 'ring with upgraded brakes. You use them quite alot, but there are some big stops and basically you NEED them to be under you when you want them. Wehrseifen is one that will tax already hot brakes and it's a hard stop Aremberg too. Those are the ones most likely to be 'hello barriers'if the brakes give up. Other hard stopping corners tend to have slower approaches and also you can probably (just) get away with arriving quicker then you thought elsewhere on the track.

Autogyro is right - especially if you can use your passenger's feet - the Fred Flintstone stopping method is a good one

[tk421]

We can go 'track' pads such as the Ferodo DS3000 which will make a huge difference but we were wondering if it was worth swapping the OEM disks for Brembo Drilled disks (same diameter etc, just drilled).
Brake fluid will be changed for Motul RBF600.

are you going to go with braided steel brake lines or leave them be?

[mx_tifoso]

But.... porsche etc fit drilled so maybe there is more to it?

Please don't look at what manufacturers use on their road cars for inspiration.

If you're really going to track the car don't do it for looks, as that's mainly why they use drilled rotors on road cars that will mainly/only see street and highway use.

From what I've learned over the past years of learning about track/sports cars is that the best* brake system upgrade is as follows: slotted rotors, braided stainless steel lines, fluid with higher boiling point, and track oriented pads. And then if needed, additional brake ducts.

IMO of course.


*Below BBK.