Couple of brake questions....

[matt_k]

Firstly, will the 323mm brembos from a cupraR fit under the standard 17" star alloys on a leon cupratdi?

Secondly, I'd like slightly bigger brakes on the rear aswell, more just for looks than anything. I think the standard size is 256mm discs? What can I use to go bigger?
A mate of mine is running the standard calipers but different carriers and 288mm discs. He has no idea what they are from though lol, anyone know what 5x100 vag cars had them?

Thanks, matt

 

[adam cupra 20vt]

would the 288 rears be the front discs from a VR6?

 

[matt_k]

Looking at disc specs the leon has 22mm thick standard rears.

The 288's on a 95- vr are 25mm thick. However the pre95 vr has 280mm discs that are 22mm thick. Maybe thats what he has?

So what carriers would fit these discs with the standard calipers?

 

[oldman]

no they will not fit under the standard front starfish 17", without at least 10mm spacers.

nice thread in the tdi forum on this, can't remember who was doing it now though.

most people go 256mm vented at the rear, but seem like rocking horse poo to find

 

[Willie]

If your wanting bigger brakes on the rear for looks you will have to remember this 24/7 when your driving as upsetting the front rear balance will make your car want to swap ends VERY quickly and easily.
LCR has 256mm rear, there is 308mm rear but your looking at £500 for this and TBH not worth it.

 

[matt_k]

Ah right, cool. Was hoping that I would get them under by running spacers, and not have to change to a larger diameter wheel.

Yeah I realise that about the rears, but I'm only going a wee bit bigger on them but a lot bigger on the front. So that should keep the balance the same I would think....

 

[volvic]

its been covered many times, bigger rears only have cosmetic gains as most of the braking is done at the front

 

[matt_k]

Yeah I know theres plenty brake question threads, but I've not seen my question about 288s on the rear being covered?

And it does say in my first post that I'm doing it for looks

 

[Willie]

With 288mm rear you'll need 345mm x 30mm fronts.
Thats alot of braking

 

[matt_k]

With 288mm rear you'll need 345mm x 30mm fronts.
Thats alot of braking

Yeah? Thats a bit bigger than I thought on the front.

Still, its good to stop fast. lol

 

[Willie]

That will allow you to keep the balance
The LCR has 323mm x 28mm fronts and 256mm x 22mm rears
If you go 288mm rear you'll need 345mm fronts

 

[matt_k]

ok, cool thanks

 

[DaveB1970]

With 288mm rear you'll need 345mm x 30mm fronts.
Thats alot of braking

Willie thats not exactly correct although you are 100% correct about maintaining a balance, the bias on the Cupra R (323's) and the Mk4 R32 is around 72/28 to the front which is a little too far forward considering the widely accepted view that 60/40 or 66/34 is more in the ideal range.

Theres a big school of thought that says that if it left the factory in a particular config then thats the way thats best and consequently how it should stay.

The fact is that the 256mm rear disc casting is exactly the same as the Mk3 golf front 256mm disc just 5 x 100 and not 4 x 100 its VW parts bin engineering at its best/worst.

The rear discs being discussed above are actually 284mm, they're an upgrade from 256's using 4WD rear carriers and calipers and not the "long throw" carriers from a V5 or Cupra R.

The 288's are too thick at 25mm and the 280mm are the correct thickness at 22mm but dont give enough room to extend the bracketry out the 284 geomtery is also better as the bracket is chunkier

The proof of the pudding is in the eating and the rearward adjustment to the bias really helps, in fact flatter braking, better stability and they also look better under 18's

Without the calipers and carriers the kit comes in at 1/3 of the ECS kit

 

[Willie]

Alright Dave.
Yup always believed thst the OEM set up was 80% front and 20% rear.
Now that I have stripped out my car the 256mm rear brakes are more than enough. I had to lower the rear tyre pressure as it felt like the car wanted to swap ends when braking hard.
Would be interested if you could give us more information on prices and equipment to do the 284mm rear set up.
I'm sure a few people would benefit from this

 

[DaveB1970]

Hi Willie

Taking into account what you said then your rears are underbraked possibly severly, imagine your brakes at the point just before they lock up or the ABS deploys, you can either overcome that tendency to lock up by fitting bigger discs with more leverage to overcome the pads ability to lock the discs up (an MOT requirement) and continue decelarating or let them lock up and have no braking/decel at all.

It sounds by your symptoms that rather than the 256's being "more than enough" they are causing you
stability issues, slighly bigger rears would help. Its no coincidence that VW went to 286's on the Mk5 Gti to help matters and stayed with the 312's up front.

All calipers can lock the brakes - thats a given.... its the amount of decelaration you can generate without locking up the wheels that gives good lap times and complements good suspension.

80/20 is what you would get with a 1.1 popular plus fiesta with drum rears!!!!

Im not an advertiser on here so cant really go into prices etc without breaking the forum rules so either PM me or do a search for 284mm or 286mm over on uk-mkivs.net.

Cheers Mate

Sounds like a good project you got a build thread?

 

[james walker]

hmmmh, interesting... as you know dave from ukmkv1s i have the porsche carreras up front on 312mm discs and standard 232mm i think cupra rears.. so am i currently massivly underbalanced then??

would the answer be for 256 rears for me with the r calipers to suit?

 

[Willie]

hmmmh, interesting... as you know dave from ukmkv1s i have the porsche carreras up front on 312mm discs and standard 232mm i think cupra rears.. so am i currently massivly underbalanced then??

would the answer be for 256 rears for me with the r calipers to suit?

You can have mine when Dave gives me a good price on new rears, lol.

Dave

I was considering the ECS stage 5 but @ £500 it just didn't seem to be worth it.
I'm very interested in this if you can supply me with the information on this by PM that would be great.
Surpried to think that the rears are not up to the job.
There are a few guys on here with the 308mm rear on OEM calipers and they say it feels great.
Now very interested in uprating the rears

 

[DaveB1970]

Hi James

Well yes it would definetely help, even going to 256's would be a step in the rearward direction in terms of balance and just before I start harping on its a rearward adjustment NOT rearward Bias Im advocating just something to help out a little.

The 284's and 300mm rears (4wd cars) have a tangible effect on how the car feels under braking, it feels more like the car is being pulled to a stop from behind rather than the fronts doing all the work it also eliminates a lot of dive that the front end gives on unmodded suspension and complements a 1/2 decent set of coilies and springs.

Just to repeat though FWD 256 rear setups WONT work, you need to change your setups to TT 256's or 4mo or R32 setups, these setups require a set of 6mm spacers to work in the past which were around the 30 quid mark, that 6mm and much more is taken up by a fairly chunky bracket that for all intents and purposes moves the mounting points for the rear calipers outwards to wards the rear of the car facilitating the bigger disc, by fiting the 6mm spacers you can remove it all and go back to a 256mm setup easily.

Theres been a lot of success over ont he other forum with people swapping their caliper carriers for those of another user. So golf owner with 232's can only find 4WD setups from breakers etc, he needs to buy the spacer kit, FWD owners such as 180BHP GTis, Anni, Cupra's, Octy VRS's want the 4WD carriers to do the conversion so they swap carriers keeping your existing calipers - normally have paint issues but thats not insurmountable.

If you have a set of TT rear calipers/carriers under your stairs and you are looking at buying OEM discs and the spacer kit then for not much more you can go staight to 284s fairly cost effectively.

If you have a FWD 256mm kit with discs/caliper/carriers and its bolt on then you have some more thinking to do.

I'll try to dig some pics out and post them up

 

[DaveB1970]

Willie post a picture of your front discs, I need to know if they are plain/drilled/grooved

 

[adam cupra 20vt]

I've got 312 on the front of mine, are you saying I can have 288 rears using the TT 256 calipers and standard spacers or do I need the extra 6mm spacers?

That would look and work awesome!