312mm brake conversion (TT setup) write up / DIY

[Mark. 2]

First off, Im not trying to piss on any previous DIY guides been done before by users of this forum, Just i found as a total new to 312mm setup i found it hard getting the answers to certain questions regarding the conversion and pictures from the old threads were no longer hosted. I did a bit of asking around to get my answers and made this guide so anybody in the future wanting to do the conversion can see this thread when they search the forum to answer any questions. Fairly simpe swap and this is how i did it.

Parts needed:

-312mm discs from an audi tt / skoda octavia vRS and some mk4s (TT part no 8N0615311A)

-caliper carriers (Audi TT caliper part no 8N0615123) (audi TT carrier part no (1)Left 8N0615124 (2)Right 8N0615125 )

(note - later spec vr6 guys with 288mm brakes can use the original caliper. early obd1/rado guys will need the caliper from either obd2 vr6 or the caliper from your donor tt/octavia vRS/mk4 - early caliper guys (obd1) need to also buy banjo type brake hoses)

-pads to suit 312mm discs (again obd2 guys can use your old pads but id reccomend buying new ones. )

-6mm plate metal (this will become clear later)

-m12 high tensile bolts at least 40mm long (your old bolts are no good)

-16" wheels at least. 15s WILL NOT WORK

here is my spacer i made. you will need to make two of these. It is VERY important you ensure the 12mm holes you drill match EXACTLY up with the 12mm holes in the carrier. This will save you trouble when it comes to putting them on the car. dont worry about it being neat, it cant be seen when its on the car.

now i was ready to install my new parts

just for comparrison 288 vs 312mm

this is the reason for your 6mm plate spacer. notice the 312mm disc has a more protruding face out of the friction area. Your spacer will make your pads and caliper line up properly with the disc.

Next stage is pretty simple, simply pulling your caliper off using an alen key on the two bolts on the back and the caliper will lift off. NOTE** do not let the caliper dangle by the brake hose, this can damage the hose, either hang it from the spring with a wire or balance it on the hub.

Remove the old caliper carrier 2x 17mm bolts and throw it away (you have a nice new one to install in its place)

Now simply bolt up you new carrier with the spacer BETWEEN THE CARRIER AND HUB with your new bolts

the rest is easy simply reinstalling everything as they came apart, replacing your brake pads with new ones.

hope this comes in handy to anybody wishing for better brakes on a budget. Its wet outside so i cant give a good feedback right now but initial impression is its a worthwhile improvement.

cheers

[tubby 0]

Nice write up mate very clear even i could follow it should be moved to knowledge vault me thinks

[philbatesvr6 0]

nice wirte up shame im running 15's

[Mark. 2]

cheers guys, The problem i had with the guides already here were some parts were unclear and it didnt help that the pictures were'nt hosted anymore. would be nice to see it moved to the knowledge vault as there is nothing in it so far on this.

[philbatesvr6 0]

im sure as soon as admin see it they will move it there for ya mate

[VR6Pete 1,455]

Handy, need some new pads for my 312mm setup, so i just need regular VR pads cool!

[craggsy 91]

Pete if you wanna upgrade pads then ask for S3 pads as they are the same

[craggsy 91]

Oh and I made it a sticky!!!!!!!

So will stay around at top of page

[VR6Pete 1,455]

might as well stick new pads on while im at it lol

nice one for the tip..

[craggsy 91]

I ordered EBC yellow stuff pads. They dont do em for TT 312s but they do for S3 312s and they are all the same

[Mark. 2]

yeh they are the same.

[C3 LJG 0]

Where would i get some longer bolts that are good enough for this conversion?

[Mark. 2]

Where would i get some longer bolts that are good enough for this conversion?

i got them from my dads work, but any engineering type place will sell them.

I put in an old bolt by mistake when putting them back together and it was only a couple threads short, you could maybe use them but people on here said to use longer ones, so i did.

when asking for the new bolts remember and ask for high tensile ones. cheap bolts might snap or bend, remember these bolts basically take all the weight of your car stopping when you hit the brakes so id make sure they are good quality

[C3 LJG 0]

Thanks mate don't suppose he can get any more, or do you know the specs of the bolts needed etc?

I have been offered a set of 312mm discs, calipers, pads and brackets off a mate for £100, and should be able to sell the calipers on as i can use my existing ones, so can make a bit of money back on them.

[orangecruz 0]

right after reading this and needing new brakes anyway i now have everything i need the only thing is the new calipers just look huge are we sure there the same anyway need to get it all on looks awesome how does it perform as good as it looks i hope??????

[vr6madmike 0]

My mate fitted these too his Mk4 I can vouch for the performance, very powerful

[OEM+ 1]

hi nice write up ive done this 312 conversion an also got the 280 rear set up as well an she stops twice as quick as before well worth doing, i used the s3 caliper an carrier. the late vr caliper an s3 or tt caliper is basically the same overall size apart from the piston is about 1mm bigger on the s3 an tt. i think im write in saying that all the pads are the same from 288mm through to 312mm.

[Chris1 0]

Hi there lads, ive just ordered a kit from vw speed, consisting of carrier discs and pads, so i'm all set apart from the spacer and the new caliper bolts, was just wondering what pitch the thread is if anyone knows. cos i'll have to buy these before i do the job many thanks guys, plus is a 40mm long bolt good enough for the job ta.

[Phat VR6 3]

Nice write up, Any idea how much the carriers are from VW? or is there a cheaper place to get them?

You forgot to mention that you need to take the cap off the brake reservoir before you start! If you don't when you push your pots back it damages your master cylinder

[Matt W 4]

If the 312mm discs protrude more (6mm hence the 6mm spacer). Is it like running 6mm spacers up front???

[binliner 0]

no... iirc it's the carrier that's offset differently that makes the spacer necessary (can't remember exactly because Tom did mine!)

[sharky_70 0]

fitted my 312's on saturday and have got a few problems since putting it all together.

1st I get a constant rubbing noise like the pad is constantly touching the disc. think its probably just settled too close and is rubbing the dissc, easy enough to fix.

what im more concerned about is the noise gets louder as i turn. i checked for cleaerance of the caliper/carrier against the wheel inner

there's also another noise i get as im moving off slowly or crawling in traffic, its intermitment rubbing/grinding. not gonna drive the sar now til i can have a look but wanna now what im looking for

as far as im concerned it was a very straightforward swap. only difference to changing the discs and padds was sticking on a different carrier. everything was tightened up properly afaik

any ideas?

[craggsy 91]

Might be a daft thing but if you have put grooved discs on the wrong side they will make a strange noise.......i did that and made a grinding noise then swapped em and it went

[VR6Pete 1,455]

I've got a full 312mm setup for sale if anyone is interested.

[sharky_70 0]

i used standard non-grooved discs