vented discs or not

[jonnyb]

i duno if i should get vented discs or just leave the ones i got on there

[waynne]

Vented discs do improve the braking a lot and quite safely but are you perhaps talking about slotted discs?

Vented are two plates with a gap between them to aid cooling and will look solid from the side. Slotted discs have lines cut into them at angles.

These clean the pads and enhance braking but I have heard about these being subject to metal fatigue due to head build up in competition settings.

Have a look at your options in torquecars.potn.com - bigger disc conversion would make even more of a difference. I would also recommend braided hoses and a good quality pad.

[gixxer600k4]

as said above vented looks like two discs together. drilled and grooved have very very little performance gains, they just slightly increase the light of the pads. if you have solid discs on there now, which is just like one plate, then for you to get vented, the one with to plates, you might be in need of some new wider calipers. im not sure but i think!!!!!!!

[old-git]

Originally Posted by gixxer600k4

as said above vented looks like two discs together. drilled and grooved have very very little performance gains, they just slightly increase the light of the pads. if you have solid discs on there now, which is just like one plate, then for you to get vented, the one with to plates, you might be in need of some new wider calipers. im not sure but i think!!!!!!!

If you upgrade from solid to vented discs, you will need to replace calipers as well.

[lyndsey]

Originally Posted by jonnyb

i duno if i should get vented discs or just leave the ones i got on there

i bought vented discs and it didnt make abit of diffrence to the car just looked better than the plain and i didnt need to replace brake calipers and u dont need to but u do need diffrent more expensive brake pads else it will screech wen u brake

[pgarner]

lyndsey i would have thought the st would have had vented discs as standard, are you thinking drilled or grooved ones ?

[old-git]

Originally Posted by lyndsey

i bought vented discs and it didnt make abit of diffrence to the car just looked better than the plain and i didnt need to replace brake calipers and u dont need to but u do need diffrent more expensive brake pads else it will screech wen u brake

How much thicker are the new discs than the original set?

[HDi fun]

Just about all modern cars now will have ventilated front discs at least. Very few cars have shoe brakes on the back now.

Mine has vented fronts and the rears are solid items. The standard discs are quite large anyway (305mm front, 291mm rear). Previous car (Primera) had slightly smaller discs all round but the car was a good few CWT lighter than the Pug.

I have not ventured into the drilled and grooved marketplace as I find the brakes more than adequate for general use. Even at high road speeds they bite firmly and evenly. Stamp on the pedal and it feels as if your eyeballs might pop out of your head.

I imagine that slotted rotors could cause lots of noise and quick pad wear problems.

[pgarner]

drilled discs have the possible of heat fatigue and cracking where as the grooved or dimpled ones wear the pad quicker, but i think the plus side is they prevent glazing. like you say a decent set of pads on standard discs can be more than adequate. i feel a big difference between mine Front 312mm and the wifes 288mm both cars similar in weight maybe around 60kg

[HDi fun]

Pads, too, are very subjective. One driver's quick and early response is another driver's early fade and poor pedal control characteristics.

I'm still on standard OEM ATE branded pads which seem to work very well indeed.

I've played with EBC's Green Stuff in the past and I've found the pads to be lacking very soon after a couple of firm applications. They are certainly cleaner than other formulations but the stopping force (not power!) is lacking once they're warmer than perhaps they should be. Yet they're marketed as a fast road pad!

The ATE pads do seem to go on and on, yes they make a mess of the alloys, but they keep on stopping even with a swift 15-20 mile drive around Milton Keynes (only a dozen or so miles from me) with all the roundabouts. And that is when I'm really making progress, braking from 85+mph repeatedly into roundabouts and accelerating firmly out of them as well.

SOmeone said I should try the Red Stuff - to be honest I think that EBC braking is a bit weak kneed. I tried the greens in the primera some years ago and apart from the astonishing early bite I cannot find reason to recommend them to anyone.

[pgarner]

think theyve changed the formulas in the last few years, used to be green for road and red for track.
now greens fast road for smaller cars
reds fast road heavier cars such as yours, and mine (only 1330kgs but its classed as heavy)
yellows track day stuff

im like you and finding the OEM pads good enough found out that they are made by pagid so might explain the near £100 VW want for them

[HDi fun]

I've read similar things about the EBC pad formulations recently. Changes were probably necessary. At this point I'm have not sense of urgency to change.

1330kgs is not a lightweight by anyones standards - VAG cars are well built.

Mine sits at a silly 1520kgs kerbside weight. So much for lightly built Peugeots? It seems that Peugeot has gone overboard years ago in a quest to build stronger cars.

The 405 series had very stiff chassis' and good handling as a result. They were little over 1000kg even in estate models.

The 406s are bloody heavy, although I'm quite certain that the diesel engines don't help in this respect. Whether or not the block is made from some curious ferrous composite doesn't matter - the front end of the diesel models can make for early understeer.

It seems that the French managed to ape the build quality of German rivals (5 series is similar in size) without considering the whole package. It does handle very well indeed, but the P11 Primera would shame it.

And all from a car that was assembled in Coventry.

Heavier is not at all better unless all other factors are considered.

[jonnyb]

thanks everyone

[jonnyb]

still duno wot to do but thanks

[waynne]

Thats always the problem with upgrades. I think you can get away with some nice pads. Unless you are driving hard or using the car on a track you wont have a lot of call for uprated brakes.

I noted you posted this in styling so if you just wanted something prettier to look at through the wheel get a set of grooved disks instead when your standard discs wear out.

[jonnyb]

yer thanks i will do that

[96AccordCoupe]

I read a pretty interesting thread a while back about how blanks are the best for braking power.

More surface area = More stopping power.

This thread had quotes from designers of exotics saying that the only reason they use drilled and grooved discs is for the aesthetics, as buyers think they are better.

I think it also said that Formula 1 cars use blanks, but that was countered by the argument that you can't have drilled carbon ceramic discs as they would crack lol

Anyways, my Accord uses 10" vented discs on the front as standard. Great stopping power for a car that weighs nearly 1500kg, but they cost £130 a pair

[HDi fun]

Do you mean vented in the way that the disc is vented around the circumference or the drilled and slotted kind?

My car uses 305mm discs on the front and they are the circumferentially vented type, but the braking surfaces are plain.

THe back ones are 288mm but solid throughout. Not much heat on these I suppose.

[gixxer600k4]

if you dont have a high performance car then getting grooved or drilled discs alone will see very very little if not no performance upgrade, maybe if you buy it as a set with some pads. cars like ferrari, top of the range merc, lambo, porsche etc dont just use drilled for look, as they are high performance/race cars, they drilled discs to keep the heat down from the pad and discs otherwise the breaking power will reduce they really do work, but on cars say like a fiesta or a civic will not need drilled discs because they wont be getting hot enough for them to need to be cooled down. fair enough if you buy them for looks ay do look good, but you will not feel much of an improvement.

also f1 cars probably do use blank discs as they have their own cooling ducts per disc, and like you say, they are carbon ceramic

[pgarner]

Should be noted that drilled discs also have more chance of facturing/cracking due to the constant heating and cooling.

[waynne]

Vented discs have an extra internal surface area to help with cooling so IMHO they are better. Drilled and grooved disks supposedly help keep the pads clearer but I wouldn't say they were better.