replacing my pads, easy enough, BUT I have noticed that both my rear discs are the same?? ie. the drilled holes both sweep the same way? the left sweep up from the centre to the front and the right sweep up from the centre to the back?
so if you lay both side by side they are the same and not left of right handed. IS THIS CORRECT? The two ap’s on the front sweep from the centre to the back so are left and right handed. car is 08 exige S and this is the first time the discs have been off from new? I will not rebuild till I here from you guys.
Yes this is same as mine…
Not ideal granted but in practice makes no real difference .
Well spotted , not many notice !!
interested to read that your AP’s are handed tho
Yes this is ‘normal’! Makes naff all difference though so wouldnt worry!
It saves in manafacturing costs for the OEM stuff.
Aftermarket stuff is tailored… have a gander at these!
http://www.seriouslylotus.com/index.php/braking/alcon-308mm-disc-with-nitron-fixed-bells.html
Thanks guys
must say never had a braking problem and did think it could be down to manufacturing costs, best get on with re assembly then.
I remember a guy at Bedford had a braking problem and the Sincs. back up engineer said his front grooved discs had been fitted the wrong way round, ie. left on right and right on left. I think all was ok once they swapped them over.
The direction of grooves can make a bit of difference as theoretically they actually wipe the face of the pads to deglaze them but as said for drilled discs it’s unlikely to have any effect.
All these ‘surface’ things allow hot gas escape! ie: no ‘air cushion’ to spoil the pad/disk interface.
However, the direction of the ‘fins/vanes’ in between the 2 disk faces it IS important the they face, they need to draw out heat from in the center to the outer edge of the disk during rotation…
AFAIR, in the standard Lotus ones the fins are not handed so not an issue. But in the AP/Alcon etc disks they are, so it’s important to get these facing the right way!
phone sent message twice … see below …
My EBC vanes are not handed … so I,m wondering if it matters much ?
As long as air is free to pass from circumference to centre or vice/versa is that all that’s required ?
I truly don’t know !
Any brake disc Guru,s out there ??
it is all to do with the vanes creating airflow to suck the cool air from the centre of the disc outwards towards the wheel, of course they will work better if the vanes head the correct direction to do that with the wheel moving forwards, hence the vanes being handed. It is not they don’t work the wrong way they are just not as efficient.
Pete,Ade…
Here’s an interesting one then …
Below are two pics of my EBC discs which are infact “handed”…
Easy to see from the first pic ?
Note,however,that in the second pic the VANES are NOT handed !!
Machined from the same blanks !!
So… if you read into this it seems direction of VANES matters not !!!
As I said i’m no disc Guru but just my observations 
Before someone cries out faulty batch,I can verify that my fronts are exactly the same,but purchased from a different supplier a year apart !!
Any thoughts?
I would suggest this is still a cost saving measure one casting machined with optimum cuts in the discs
I absolutely agree…
What would be interesting tho is the difference it makes having the vanes opposing each other??
What he said^^^^^^
They are done this way to save money, I’m not sure how big the difference would be but there will be one, the vanes face in a certain direction to create the airflow from the inside of the disc out to the wheel, it can’t be as efficient if the vane is running the opposite way to the direction of travel.
Vanity!
Plenty of that on here lately 
perhaps we should strap some on to Whiteys car for a test !!!
[quote=jfk]perhaps we should strap some on to Whitey for a test !!!
[/quote]
fixed that for you
sorry guys I seem to have opened a can of worms here.
But you would think that the vane direction, once spinning, would have some impact, My vote would be for the direction that the ap’s go. ie swept to the back. I would have thought this would draw air out of the outside edge of the disc.
One other small thing, should I re assemble using locktight or similar?
Not a can of worms, but a good chance for us all to learn a bit more and things to look out for
As for locktight I have never used any on my brake components.
Vane direction does matter. You pays ya money and you takes your choice! It would be interesting at a track day to measure the heat of each disk just as you come off track. I will bring my temp gun to Anglesey
Excellento …