10 replies to this topic

[freshairmini]

Hi,

I have a 1990 Cooper RSP with the standard AP 8.4" disc brakes.

I am planning on giving them an overall in an attempt to get the best braking.

I see you can get brake discs in standard (about £11 each), grooved, drilled or both grooved and drilled (for considerably more money).

what is best? does the extra drill/grooving make any difference in a standard road vehicle?

What are the opinions on this?

Thanks!

(also vented discs are not an option on standard brakes, do not suggest )

Edited by freshairmini, 13 January 2012 - 01:18 PM.

[Beej123]

Grooved and drilled, they will stay cool better, that's the only real difference. If used with a good set of pads then they will be the best. If it's just a normal every day car you will not likely notice any difference between the 3 at all.

[Barman]

http://www.theminifo..._1#entry2309329

[freshairmini]

http://www.theminifo..._1#entry2309329

Thanks barman

Looks like the standard ones are fine!

[Cooperman]

The question is 'best for what?'
For road use standard discs ae best, so long as they are the best quality material anmd rthe best quality standard pads.
Disc brakes operate when the pads are within the correct operating temperature range. Too cool and you lose friction and too hot you lose friction.
For competition different considerations apply.
If you drive 'briskly', then a slightly better pad material can be an advantage, such as EBC 'Green'.

[TA2DMAC]

Unless you plan to ralley or race standards are fine. Vented or slotted discs are designed to cool the brakes down when doing a lot of braking.

[freshairmini]

The question is 'best for what?'
For road use standard discs ae best, so long as they are the best quality material anmd rthe best quality standard pads.
Disc brakes operate when the pads are within the correct operating temperature range. Too cool and you lose friction and too hot you lose friction.
For competition different considerations apply.
If you drive 'briskly', then a slightly better pad material can be an advantage, such as EBC 'Green'.

Yeah so I guess as a road car the standard disks will be best, you said about good quality disks, can you recommend any?

Also I had read about the EBC green stuff pads, I would say I do rive 'Briskly' but I have heard that these only really work when on a track, like braking allot to get them warm. For road use would that really be the same? would you still recommend the green stuff pads for road use?

I have heard good things about the mintex M1144 pads, can you comment one them?

Thanks.

[Cooperman]

If you buy the best quality 8.4" discs that Mini Spares do then they'll be fine.
As for pad material, the Green Stuff don't seem able to cope with competition use, although they are good on the road. I have EBC Green in my 1973 Innocenti Cooper 1300 and find them excellent. Mintex 1144 are also very good as they are at the bottom end of the Mintex competition range. In my Rover 214Si rally car, for example, I use Mintex 1177 but I do get the discs actually glowing bright red at times.
If you drive briskly on the roads you'll find Green Stuff will work very well, but the M1144 might be a bit 'overkill' although they'll still work fine. I think if you had vented and cross drilled discs you might find that neither of those got to a sensible working temperature though.

[freshairmini]

Interesting.

I'm not ale to have vented disk on mine too wide apparently, I think I would need something like the metro 4pots.

So I guess it's be plain discs and I'll give he EBC green stuff pads ago and see how they are.

Thanks again.

[Dan]

Contrary to what's written here, neither drilling or grooving of discs is intended to reduce the temperature of the brakes. Only venting does that. In fact by dissipating the same amount of energy into less material under braking the temperature will probably be slightly higher than with a flat disc. Grooving is intended to remove dust build up on the surface and drilling / dimpling to release gasses that collect between the pad and disc. If the amount of surface area removed from the disc in the process is less than the amount of surface contact that is compromised by the contaminants then the result will be more contact area and so better brakes. If you go randomly cutting great lumps out of the disc, in a pattern chosen because it looks nice, you might easily remove more material than you need to and so end up with worse brakes.

I have to say I have found Greenstuff to be very disappointing in road use, I swapped back to Mintex years ago.

[cooperrodeo]

This probably won't be a problem in a Mini but I fitted grooved discs to my Triumph Spitfire and was irritated by the rotor noise, so I dumped them.