GolfGTIforum.co.uk

Model specific boards => Golf mk3 => Topic started by: sharki786 on 19 December 2012, 10:10

Title: brake dics advse needed
Post by: sharki786 on 19 December 2012, 10:10
Need to do my braking VERY soon. I got my rear yellow stuff pads just need to get my fronts now. But  thing is that i need some good discs i want grooved discs as i have them on nw & im very happy with them. I have seen sone black diamond on ebay but just the fronts are 125 then i have the rears to sort aswell. But then again on ebay there is a grooved discs (fronts) for under 90 is it worth me getting black diamond or not?

Thanks
Title: Re: brake dics advse needed
Post by: Len on 19 December 2012, 12:32
Unless your car is super powerful and goes at over 150mph then you really dont need grooved discs!
Title: Re: brake dics advse needed
Post by: Khare on 19 December 2012, 12:36
Grooved discs will wear your pads much faster, one of their functions is to grate the face to keep it clean and de-glazed. Just get some quality standard discs alongside your yellowstuff pads and you'll be good for fast road use.
Title: Re: brake dics advse needed
Post by: sharki786 on 19 December 2012, 13:46
Well i have had these for 4 years without a problemo
Title: Re: brake dics advse needed
Post by: Len on 19 December 2012, 14:10
You are actually losing braking performance with grooved discs as the surface area is less!
Grooved or crossdrilled discs are only meant to be used with twin pot (or more pot) calipers.

But hey if you want to pay £50 a disc more just for scene points........
Title: Re: brake dics advse needed
Post by: sharki786 on 19 December 2012, 17:15
Ok point taken. Recommend me some discs then plz   :kiss:
Title: Re: brake dics advse needed
Post by: sharki786 on 19 December 2012, 17:17
But dont you get gas build up on non grooved discs?
Title: Re: brake dics advse needed
Post by: tweed on 19 December 2012, 17:30
I noticed less fade when I swapped from standard to grooved.

Also you can get smooth grooves so infact they don't cut the pad.

I would get them again.

If you like to drive fast and use the brake hard then get grooved. Defiantly helped my brake fade.
Title: Re: brake dics advse needed
Post by: sharki786 on 19 December 2012, 17:36
I noticed less fade when I swapped from standard to grooved.

Also you can get smooth grooves so infact they don't cut the pad.

I would get them again.

If you like to drive fast and use the brake hard then get grooved. Defiantly helped my brake fade.

Ok which discs did you get then? & how much?
Title: Re: brake dics advse needed
Post by: tweed on 19 December 2012, 17:53
I noticed less fade when I swapped from standard to grooved.

Also you can get smooth grooves so infact they don't cut the pad.

I would get them again.

If you like to drive fast and use the brake hard then get grooved. Defiantly helped my brake fade.

Ok which discs did you get then? & how much?

These I think. Was few years back http://www.ebay.co.uk/itm/GROOVED-BRAKE-DISCS-FRONT-MK3-GOLF-2-8-VR6-288MM-95-97-/180315424359?pt=UK_CarsParts_Vehicles_CarParts_SM&fits=Model%3AGolf%7CPlat_Gen%3AMK%20III%7CCars%20Type%3A2.8%20VR6&hash=item29fba30667&_uhb=1 (http://www.ebay.co.uk/itm/GROOVED-BRAKE-DISCS-FRONT-MK3-GOLF-2-8-VR6-288MM-95-97-/180315424359?pt=UK_CarsParts_Vehicles_CarParts_SM&fits=Model%3AGolf%7CPlat_Gen%3AMK%20III%7CCars%20Type%3A2.8%20VR6&hash=item29fba30667&_uhb=1)
Title: Re: brake dics advse needed
Post by: sharki786 on 19 December 2012, 19:41
I noticed less fade when I swapped from standard to grooved.

Also you can get smooth grooves so infact they don't cut the pad.

I would get them again.

If you like to drive fast and use the brake hard then get grooved. Defiantly helped my brake fade.

You got them from same people?
I have just messaged them for front & rear

Thanks for that info peeps

Ok which discs did you get then? & how much?

These I think. Was few years back http://www.ebay.co.uk/itm/GROOVED-BRAKE-DISCS-FRONT-MK3-GOLF-2-8-VR6-288MM-95-97-/180315424359?pt=UK_CarsParts_Vehicles_CarParts_SM&fits=Model%3AGolf%7CPlat_Gen%3AMK%20III%7CCars%20Type%3A2.8%20VR6&hash=item29fba30667&_uhb=1 (http://www.ebay.co.uk/itm/GROOVED-BRAKE-DISCS-FRONT-MK3-GOLF-2-8-VR6-288MM-95-97-/180315424359?pt=UK_CarsParts_Vehicles_CarParts_SM&fits=Model%3AGolf%7CPlat_Gen%3AMK%20III%7CCars%20Type%3A2.8%20VR6&hash=item29fba30667&_uhb=1)
Title: Re: brake dics advse needed
Post by: tweed on 19 December 2012, 20:13
Yeah think so. I only got front because you don't need them for rear  :wink:
Title: Re: brake dics advse needed
Post by: Screech16v on 19 December 2012, 20:21
Grooves  FTW.
Title: Re: brake dics advse needed
Post by: Len on 19 December 2012, 20:46
Ok point taken. Recommend me some discs then plz   :kiss:

Black Diamond
Title: Re: brake dics advse needed
Post by: Ess_Three on 19 December 2012, 21:29
Unless your car is super powerful and goes at over 150mph then you really dont need grooved discs!

Utter rubbish.
It's not about top speed...it's about how hard you use them, and how hot you get them.
Title: Re: brake dics advse needed
Post by: Ess_Three on 19 December 2012, 21:31
You are actually losing braking performance with grooved discs as the surface area is less!
Grooved or crossdrilled discs are only meant to be used with twin pot (or more pot) calipers.


Also utter rubbish.
I love the missinf-ormation on this forum.
Title: Re: brake dics advse needed
Post by: Ess_Three on 19 December 2012, 21:32
But dont you get gas build up on non grooved discs?

Yes...
If you get good pads hot enough...or use crap pads.
Title: Re: brake dics advse needed
Post by: vwwvgolf on 20 December 2012, 08:07
i will be getting grooved black diamonds again soon. i had some on my old 1.4 along with black diamond pads and the difference with the standard ones it had on before was unbelievable.

and that was a 1.4! defiantly not super powerful and never got close to 150mph
Title: Re: brake dics advse needed
Post by: sharki786 on 20 December 2012, 09:22
Defo getting grooved then. Cant afford black diamonds
Title: Re: brake dics advse needed
Post by: Len on 20 December 2012, 12:23
But dont you get gas build up on non grooved discs?

Yes...
If you get good pads hot enough...or use crap pads.

So what is this gas?
Does it actually form a barrier between the disc and pad?
Title: Re: brake dics advse needed
Post by: Len on 20 December 2012, 12:26
Unless your car is super powerful and goes at over 150mph then you really dont need grooved discs!

Utter rubbish.
It's not about top speed...it's about how hard you use them, and how hot you get them.


Well I guess in the wilds of Scotland you can go really really fast on open roads but down here that is impossible!
I have been driving as fast as possible for a very long time now and I have never encountered brake fade on normal roads.
Title: Re: brake dics advse needed
Post by: Len on 20 December 2012, 12:27
Note to OP.

If you really feel you need extra braking power why not do the 312mm brake upgrads?
Title: Re: brake dics advse needed
Post by: Khare on 20 December 2012, 13:03
Unless your car is super powerful and goes at over 150mph then you really dont need grooved discs!

Utter rubbish.
It's not about top speed...it's about how hard you use them, and how hot you get them.


Well I guess in the wilds of Scotland you can go really really fast on open roads but down here that is impossible!
I have been driving as fast as possible for a very long time now and I have never encountered brake fade on normal roads.

Obviously not tried going from Bournemouth to Bristol airport on a quiet day with virtually no traffic  :lipsrsealed:
Title: Re: brake dics advse needed
Post by: Ess_Three on 20 December 2012, 14:14

So what is this gas?
Does it actually form a barrier between the disc and pad?

Its the gas layer formed when the pad starts to overheat and break down...it comes from the pad material.
And yes, it forms a barrier between the friction surfaces.
Vent it - via holes or grooves, and you get rid of it.
Title: Re: brake dics advse needed
Post by: Ess_Three on 20 December 2012, 14:20
Well I guess in the wilds of Scotland you can go really really fast on open roads but down here that is impossible!
I have been driving as fast as possible for a very long time now and I have never encountered brake fade on normal roads.

Nothing to do with it.
There aren't too many Mk3s that will do 150 MPH, never mind suffer braking problems associated with high speed braking.
Brakes overheat when you use them hard without enough cooling air to control the temperatures...so repeated hard braking from modest speeds will overheat brakes quicker than brakes with 150MPH whistling past them, cooling them.

It's not about how fast you drive...its a function of how hard you use your brakes, and how much time you give them between doing work, to cool down.

I used to overheat brakes on back roads at 50-80...slowing down to 20-30...as you do on twisty country roads.

So, you can then start to take steps to stop the overheating:
Higher temperature rated pads
Higher temperature rated fluid
Grooved/drilled discs
Brake cooling
Title: Re: brake dics advse needed
Post by: tweed on 20 December 2012, 15:24
I try to stay away from drilled as they do crack.

My kart disc has many cracks  :grin:
Title: Re: brake dics advse needed
Post by: Len on 20 December 2012, 15:34
Well I would love to find a road I could do 80 on! Except motorway of course, even then 80 at peak times can be an achievement!
Most roads I travel on you are lucky to do 50.

Still sceptical about the gas.
Gas can only be formed when a material changes state, solid to liquid to gas is the general thing.
So you are saying a solid material goes straight from solid to gas? I have never seen a brake disc red hot so just dont believe this!
Title: Re: brake dics advse needed
Post by: trog_nfs on 20 December 2012, 15:53
Well I would love to find a road I could do 80 on! Except motorway of course, even then 80 at peak times can be an achievement!
Most roads I travel on you are lucky to do 50.

Still sceptical about the gas.
Gas can only be formed when a material changes state, solid to liquid to gas is the general thing.
So you are saying a solid material goes straight from solid to gas? I have never seen a brake disc red hot so just dont believe this!

Its called sublimation. Dry ice is an example of this process, where solid carbon dioxide turns directly into the gaseous form without the liquid intermediate step.
Title: Re: brake dics advse needed
Post by: tweed on 20 December 2012, 16:08
Read this Len

http://en.m.wikipedia.org/wiki/Brake_fade (http://en.m.wikipedia.org/wiki/Brake_fade)
Title: Re: brake dics advse needed
Post by: sharki786 on 20 December 2012, 17:34
Note to OP.

If you really feel you need extra braking power why not do the 312mm brake upgrads?
Well i was thinking about this but as im running bbs rx2's i will nees to shave my calipers down a little bit which i aint fund of doing. Otherwise id love to go 312
Title: Re: brake dics advse needed
Post by: Ess_Three on 20 December 2012, 20:21
Well I would love to find a road I could do 80 on! Except motorway of course, even then 80 at peak times can be an achievement!
Most roads I travel on you are lucky to do 50.

Just because YOU can't, doesn't make it impossible....does it?

Quote
Still sceptical about the gas.
Gas can only be formed when a material changes state, solid to liquid to gas is the general thing.
So you are saying a solid material goes straight from solid to gas?

So the rest of the braking world are all wrong, and you are right?
Is that it?  :whistle:

Quote
I have never seen a brake disc red hot so just dont believe this!

I've had mine cherry red...
But you don't need them red hot. In fact, if they were red hot they'd deform as they'd be malleable.

Anyway, all you need is the discs to be hotter than the temperature rating of the pads, and you fade.

If you don't believe me, go find a quiet road - a difficult job in your case it seems - and do some heavy braking then measure the disc temperature with an IR gun.
100s of degrees C is easily seen...the wheel gets hot enough to boil water on contact.
Why do you thing repeated heavy braking also kills track rod ends and ball joints?
(Heat)

Cheap pads glaze over at low temperatures...then you press even harder trying to brake, and get the gas layer...it's a lose lose situation.
Fit decent pads and decent discs and the problem goes away for most road driving.
Title: Re: brake dics advse needed
Post by: F17BAD on 20 December 2012, 22:25
Iv had my old 280's Glowing hot too. and smoke pouring off as tho they were about to set fire

this was main reason i moved to a 312 set up
Title: Re: brake dics advse needed
Post by: sharki786 on 20 December 2012, 23:26
Do you watch le-mans or rally? I have defo seen their discz glowing orange!  The more & harder you use your brakes the hotter they get due to friction & gas build up on the surface or discs & pads
Title: Re: brake dics advse needed
Post by: Leroy on 21 December 2012, 08:45
I had grooved discs on my old 8v with green stuff pads and was noticeably better than the standard setup ive got on the 16v. But i thought  GREEN stuff pads were best for fast road use as the YELLOW and RED stuff pads didn't start working properly until they are at much higher temperatures and were therefore more for track use???

In fact, just been on the EBC website and they recommend green for cars under 200bhp for fast road use, red for performance cars over 200bhp and yellow for hot hatches to american muscle cars and occasional track day use?

Wouldn't green stuff pads been the best option? or otherwise your brakes won't work very well unless you are thrashing it everywhere???

Title: Re: brake dics advse needed
Post by: Ess_Three on 21 December 2012, 09:44
Iv had my old 280's Glowing hot too. and smoke pouring off as tho they were about to set fire

this was main reason i moved to a 312 set up

No you didn't.
You were mistaken.
Len say so  :whistle:
Title: Re: brake dics advse needed
Post by: Ess_Three on 21 December 2012, 09:47
I had grooved discs on my old 8v with green stuff pads and was noticeably better than the standard setup ive got on the 16v. But i thought  GREEN stuff pads were best for fast road use as the YELLOW and RED stuff pads didn't start working properly until they are at much higher temperatures and were therefore more for track use???

In fact, just been on the EBC website and they recommend green for cars under 200bhp for fast road use, red for performance cars over 200bhp and yellow for hot hatches to american muscle cars and occasional track day use?

Wouldn't green stuff pads been the best option? or otherwise your brakes won't work very well unless you are thrashing it everywhere???

I used Greenstuff pads when the car was more standard, and found them pretty good.
They work from cold, aren't noisy and don't give off much dust.

As the power rises, suspension gets improved and brakes get used harder, I found them lacking...but then a Ferodo DS2500/Miltex M1155 upgrade is an obvious step.
Title: Re: brake dics advse needed
Post by: thai-wronghorse on 21 December 2012, 10:10
I had EBC Greenstuff on my last mk2 16V and really wasn't overly impressed tbh.
Title: Re: brake dics advse needed
Post by: Khare on 21 December 2012, 10:30
I've got Mintex M1144 on the front and find them good, but have made them fade once or twice on the roads.
Title: Re: brake dics advse needed
Post by: Len on 21 December 2012, 13:07
My point is you are defying the Laws of Physics.

I repeat solid-liquid-gas

To change state you have to apply heat or pressure, which indeed we have in this case.
But what is being said is that a reaction takes place that the pad material goes from solid to gas all in just one reaction.
That is what I do not believe is possible.

If there is gas then it would be far simpler and way cheaper to put groves in the pads. Why is this not done?
Cross-drilling is done to aid cooling of the disc.
Grooves are to assist the dispersal of dust/debris.
Title: Re: brake dics advse needed
Post by: Len on 21 December 2012, 13:17
Oh and I see a lot of childish, derisory comments but no facts!

I asked what these gases are!

I also guess again, as no facts are forthcoming, that these said gases are coming from the pad material?
Can somebody say what is in the pad material that gives of gases?

As I assume it doesnt come from the disc as that would require vast heat and pressure to vaporise!

It used to be a lot of asbestos that was great at doing its job but a bit carcenagenic unfortunately!
Title: Re: brake dics advse needed
Post by: tweed on 21 December 2012, 13:47
http://m.youtube.com/watch?v=1tmQ5pMrFl0 (http://m.youtube.com/watch?v=1tmQ5pMrFl0)

Don't know what the gas is but mainly carbon
Title: Re: brake dics advse needed
Post by: leigh_harty on 21 December 2012, 15:50

I used Greenstuff pads when the car was more standard, and found them pretty good.
They work from cold, aren't noisy and don't give off much dust.

As the power rises, suspension gets improved and brakes get used harder, I found them lacking...but then a Ferodo DS2500/Miltex M1155 upgrade is an obvious step.

I found the 1st 1500miles or so they would squeak driving slowly but the rest i agree with. Maybe they fade abit quicker due to the vr's extra weight
Title: Re: brake dics advse needed
Post by: Ess_Three on 21 December 2012, 15:51
Cross-drilling is done to aid cooling of the disc.

Wrong.
That's what the internal venting is for.
The holes add nothing by way of cooling.

Quote
Grooves are to assist the dispersal of dust/debris.

Wrong again...they are to vent the gas layer. The fact that Tarox 40 grooved have grooves so fine that debris doesn't pass through them blows your theory.
Title: Re: brake dics advse needed
Post by: Ess_Three on 21 December 2012, 15:54

I found the 1st 1500miles or so they would squeak driving slowly but the rest i agree with. Maybe they fade abit quicker due to the vr's extra weight

This is normally a function of the pads not being bedded in properly to the disc.

If you carry out a good bedding in procedure and leave a nice layer of pad material on the disc from new, they rarely squeal or squeak.