Upgrading 312mm brakes on 1.8

[Giuseppe Busso]

Hello Seatcupra. I own a mk3 1.8 with about 250ps at this moment. I was thinking to upgrade the 312 x 25 mm front brakes with the bolt-on kit from Cupra (aka Golf mk7 GTi Performance Pack) with the single pot of 340 x 30 mm and put braided brake lines all around.
Brembo Prime discs and OEM pads.

What is your opinion about that move? Speaking about costs, i can have them on my car with 800 euros.

 

[SuperV8]

Hello Seatcupra. I own a mk3 1.8 with about 250ps at this moment. I was thinking to upgrade the 312 x 25 mm front brakes with the bolt-on kit from Cupra (aka Golf mk7 GTi Performance Pack) with the single pot of 340 x 30 mm and put braided brake lines all around.
Brembo Prime discs and OEM pads.

What is your opinion about that move? Speaking about costs, i can have them on my car with 800 euros.

What are your intentions with the car?

The 312x25 discs and decent pads are a good setup for any road driving.
If you are planning on track use then the extra heat capacity of the 340 discs will be beneficial with repeated highspeed stops.

If its just a road car and just for looks its your choice.
Don't expect shorter stopping distances - the standard brakes are more than good enough to brake more than the tyres can cope with - so adding more brake won't be a help over a few stops (5-10) - only for the extra heat capacity over extended high speed stops - which you'd never see on the road.

The 340 disc is also used with larger rear brake - so I would also factor in upgrading the rear to keep your braking force balanced.

When I upgraded my Audi A4 B6 brakes I also coded the brakes module so the car 'knew' the brakes where larger - not sure if this is required for the MQB platform?

 

[Giuseppe Busso]

340x30 it is.
OEM brake pad and brembo coated line disk. We also installed braided brake lines (red color) at the front only. At rear the mechanic said that the rubber part of the brake line is too small and it doesn't them at this moment.

Very happy with the result optically. I have to do some kilometers and then i will start to work them harder.

 

[SuperV8]

340x30 it is.
OEM brake pad and brembo coated line disk. We also installed braided brake lines (red color) at the front only. At rear the mechanic said that the rubber part of the brake line is too small and it doesn't them at this moment.

Very happy with the result optically. I have to do some kilometers and then i will start to work them harder.

Nice, the 340x30 is a heavy disc - I have some at work at the moment and I went to move them and thought wow they have some gravity in them

How about your rear brakes as I recommended previously?
I would seriously look into changing these as well so your braking system stays balanced between your front and rear axle.

Its like fitting some nice sticky performance tyres to one axle - and leaving eco/low friction tyres on the other axle!

 

[Giuseppe Busso]

Nice, the 340x30 is a heavy disc - I have some at work at the moment and I went to move them and thought wow they have some gravity in them

How about your rear brakes as I recommended previously?
I would seriously look into changing these as well so your braking system stays balanced between your front and rear axle.

Its like fitting some nice sticky performance tyres to one axle - and leaving eco/low friction tyres on the other axle!

Indeed. Too heavy but as i live with them day by day, i see that they are strong.

About weights: 312mm disk weighs 8,6kg and 340mm 10,8kg. Calipers & pads are off course heavier too (i don't know how much exactly).

I read your recommendation but first i want to live with them at this moment to see if braking is proper or not.
My mechanic says that i won't have any problem at this horsepower. We 'll see.

Thank you...

 

[v3nom]

Indeed. Too heavy but as i live with them day by day, i see that they are strong.

About weights: 312mm disk weighs 8,6kg and 340mm 10,8kg. Calipers & pads are off course heavier too (i don't know how much exactly).

I read your recommendation but first i want to live with them at this moment to see if braking is proper or not.
My mechanic says that i won't have any problem at this horsepower. We 'll see.

Thank you...

Hi Giuseppe, I'm planning to do the same upgrade on my 1.8 tsi 4x4. How does the car feel after you've put some distance on it? The parts needed are just the dust shields, longer brake line, caliper with a carrier and disc?

Regards,

Vaclav

 

[SuperV8]

Hi Giuseppe, I'm planning to do the same upgrade on my 1.8 tsi 4x4. How does the car feel after you've put some distance on it? The parts needed are just the dust shields, longer brake line, caliper with a carrier and disc?

Regards,

Vaclav

and pads..

 

[Giuseppe Busso]

Hi Giuseppe, I'm planning to do the same upgrade on my 1.8 tsi 4x4. How does the car feel after you've put some distance on it? The parts needed are just the dust shields, longer brake line, caliper with a carrier and disc?

Regards,

Vaclav

Hey Vaclav,

These brakes a very good upgrade for our 1.8 Leon. Braking from 220km/h to 80 is really good. And that's all I wanted. My car now is 380hp.

 

[v3nom]

Hey Vaclav,

These brakes a very good upgrade for our 1.8 Leon. Braking from 220km/h to 80 is really good. And that's all I wanted. My car now is 380hp.

Did you perform any ABS coding? 380hp omfg

 

[Giuseppe Busso]

Did you perform any ABS coding? 380hp omfg

No, I don't.

 

[Michael_LeonV]

Thread revival for a newbie !!

This front swap/upgrade is exactly what I want to do on my current 2024 Cupra Leon V. I'd rather stick with stock available to make any insurance issues a non-event. This is a list of the part numbers that I found on a Golf Mk7 website :

Left Caliper 3C0615123 (silver, zinc plated version)
Right Caliper 3C0615124 (silver, zinc plated version)
Caliper Carrier Left 3Q0615125 (silver one)
Caliper Carrier Right 3Q0615126 (silver one)
Brake pads 8V0698151C / 5Q0698151AJ
Brake rotor 5Q0615301G (Blank) / 5Q0615301C (2-piece drilled OEM from clubsport)/ 5Q0615301P (2-piece blank OEM from T-roc R)
Splash shield left 5Q0615311F
Splash shield right 5Q0615312F

I also want to do the rears as well to the 310x22mm vented (currently the 272x10mm solids), so need to work out the part numbers required - @SuperV8 - any hints ?

Located in Australia, so parts may be expensive here, but any best OS suppliers for them ?

 

[Michael_LeonV]

Well, a lucky browse on Farceberk Marketplace yielded a full set (calipers, rotors (340x30 & 310x22), pads, dust shields and hoses) of big brakes from a Mk7 Golf R, all for the princely sum of A$735 delivered to my work in Adelaide (that's about GPB 385 or Euro 460) which is great.

The bonus is that the rotors & pads are in great nick !

 

[SuperV8]

Well, a lucky browse on Farceberk Marketplace yielded a full set (calipers, rotors (340x30 & 310x22), pads, dust shields and hoses) of big brakes from a Mk7 Golf R, all for the princely sum of A$735 delivered to my work in Adelaide (that's about GPB 385 or Euro 460) which is great.

The bonus is that the rotors & pads are in great nick !

I would be careful if fitting used discs.
DTV (disc thickness variation) is measured in microns and the main cause of brake judder.
To measure it you need an 0.001mm resolution micrometer - and measure the disc thickness in 8 divisions around the disc. If you measure more than 0.015mm variance between the biggest and smallest I wouldn't use them.
Also make sure the friction surface is clear and shiny - any vertical lines/grooves/corrosion - then I also wouldn't use them.
These 340mm & 310 full cast iron discs aren't expensive - for me I would just get decent aftermarket discs, unless these used discs are genuine VAG & prefect.
If you were looking at composite discs (alloy hub) which are much more expensive, then inspected used ones make more sense to me.

 

[Glosphil]

For sensible driving on public roads the only results of changing to 340mm discs are expense, looks & increased unsprung weight; but it's your car so your decision. Hope you also give as much thought to your tyres braking ability, particularly in the wet.

 

[Michael_LeonV]

For sensible driving on public roads the only results of changing to 340mm discs are expense, looks & increased unsprung weight; but it's your car so your decision. Hope you also give as much thought to your tyres braking ability, particularly in the wet.

I hear you, and for most of the driving I do, it is a backward step.
but having the Adelaide hills on my doorstep, the occasional fang, the brakes will be more than worth it.
With only 18” rims, there is the offset of lighter wheels and tyres vs the models that normally have this package with 19” or 20” rims. So not as bad.

re used rotors - agree that I need to be careful, and will have time to check them thoroughly. A new set of rotors will be between $500 and $750 for all 4 depending on what version.
The ones that come with the package are original VAG.
car has only just done over 100km, so will take my time before fitting them !

 

[Michael_LeonV]

I would be careful if fitting used discs.
....
These 340mm & 310 full cast iron discs aren't expensive - for me I would just get decent aftermarket discs, unless these used discs are genuine VAG & prefect.
If you were looking at composite discs (alloy hub) which are much more expensive, then inspected used ones make more sense to me.

Well, as luck would have it, one local supplier who already had a 20% off listing had already been saved, but then through fleabay, had an extra 15% off with free shipping. So duly got some lightly slotted F&R rotors for A$600 delivered (about GBP315).
The calipers & other hardware from the Mk7 Golf R are getting shipped today

 

[Michael_LeonV]

New rotors ordered (and on their way) as well - others will be kept as spares, but may be used if good enough and measurements pass per SuperV8 guidance.

 

[SuperV8]

car has only just done over 100km, so will take my time before fitting them !

Do you mean 100,000 miles or 100 kilometers?
If the former I think the discs will be only fit for the bin!

 

[Michael_LeonV]

Nope, 100 km only.
Only had it for 2 weeks