dazdavies

iTrader: (22)

The grooves dont give an indication as to which way the vanes run as they differ across brands.

The grooves serve several purposes. They de-glaze the pads, dissipate heat on the disc surface and it provides a channel for the gases that the pad to disc friction creates. Without these grooves the gases get trapped between disc and pad and thus reduces braking efficiency.

Holed discs are good but wont last very long and crack will start to appear between the holes when used on a road car. Best bet for a road car is grooved discs without holes.

wrighty338

iTrader: (33)

Well my fronts didnt come with directional stickers on the discs and i thought the same as you, but my rears lot did so therefor i fitted mine the way K-sport wanted them to be fitted.

Abx

iTrader: (15)

Grooved/drilled discs I have used in the past had Left and Right stamped on the inner side of the disc, black diamond.

Black-Hawk

iTrader: (4)

They are fitted correctly mate, hav'nt unwrapped mine yet and they still have the rotation stickers on, looking good btw

dazdavies

iTrader: (22)

I thought I'd post up for the benfit of those that don't have the stickers when the discs arrive.

The images below are the correct way to mount your discs for maximum brake cooling.

This is off side front.



The diagram below shows which way the vanes should be angled for maximum brake cooling efficiency.


Let me also clarify that your brakes will still work perfectly well if you have been unfortunate enough to mount them with the vanes the other way it's just they'll heat up more quicky (a benefit in the winter months) but they wont cool as well when on track or braking from high speed.

As said this isn't just me spouting off an un informed opinion I asked the same question last year when I bought a second hand pair of stop tech brakes. I was fortunate enough to be given the right answer from someone whos worked in the motorsport industry in a technical capacity for many years.

wrighty338

iTrader: (33)

Daz, why would k-sport beg to differ then and tell all their customers to mount them the opposite way to what your saying?

Anger

iTrader: (4)

Daz the K sports fitted above are the right way around as the vents face straight on for cooling, its just the vanes that go the other way

dazdavies

iTrader: (22)

John,

I have no idea which way the vent vanes on the Ksports go in relation to the grooves on the outside friction surface of the disc and to be honest it doesn't matter. It's the orientation of the vanes that matters as the grooves can face which ever direction as they serve their purpose either way.
Have a look at the thread on 22b that I posted earlier. See John Felstead's reply among others. We all know John's excellent motorsport/technical background. I'm just going on what they've said and it makes perfect sense as hot air needs to be vented out to keep the discs and hubs cool. If all the vents are doing is sucking cold air in then that new cold air clashes with, and is heated up by, the heat coming off the hubs.

To be honest this is probably irrelivent for most people as the brakes will be excellent either way. They will however be more efficient and keep cooler (especially on track) if the vanes vent the heat generated by the hubs out.

This is also what AP racing suggest for their discs too.

http://www.apracing.com/info/info.as...ntification_41

wrighty338

iTrader: (33)

yea i know what your saying im just wondering why k-sport would say fit them the 'lesser' efficient way which is what i dont get

GazTheHat

I've only done about 40 miles, so not yet. Takes me a while to do 200 odd.

They're the 356mm ones.

I'm looking forward to getting them bedded in and comparing. I just need to check they're fitted right, as it seems they are catching, like minor ABS, not constant braking. Don't know if that's part of the bedding in or fitted wrong.

GazTheHat

Aye, from the GB. Not bedded in yet, so no comparison yet.

GazTheHat

Thanks mate. I saw those stickers but didn't take any notice. I just presumed they would be fitted as per instructions. It was only the comments on here that got me concerned.

Now i just need to check the discs are not catching. Fun n' games.

wrighty338

iTrader: (33)

are they 17's your running gaz?

GazTheHat

All this jibber-jabber about vanes, i had to go check. Mine spin the air out, like Daz says.

GazTheHat

18" Rota GRA's

wrighty338

iTrader: (33)

damn i wish i went for 356 discs now lol