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WRX brakes on a beetle - Advice please
maloo - June 1st, 2016 at 01:33 PM

Hi All

I have a WRX donor vehicle and am considering using the disc brakes from it on my 62 beetle.

I have the wide 5 disc brakes on the beetle already and I cant use the calipers from the WRX as the stud pattern is to wide to fit the calipers on. Hence using the WRX discs.

I dont mind changing the stud pattern and replacing the wheels.

Has anyone done this?

Any advice on the best way to approach it would be appreciated.

Thanks

Mark


1303Steve - June 1st, 2016 at 07:59 PM

talk to Todd at Subarugears


Birdman - June 1st, 2016 at 08:42 PM

Yeah Subarugears will sort you out no problem but realize you will need to go up to a 16 or 17 inch wheel depending on what caliper you use.


maloo - June 2nd, 2016 at 10:33 AM

Thanks guys will do.


Birdman I will be contacting you shortly regarding your IRS kit.

Cheers


Mark


psimitar - June 3rd, 2016 at 12:26 AM

If you've already got a wide 5 brake disc kit fitted then why do you want to fit the WRX stuff?

The Beetle is more biased towards the rear than an Impreza so even if you fitted the front and rear brakes from the WRX the bias would be more forward braked than what a Beetle should be.

Nothing wrong with going vented disc on the front of a Bug if you just have the solid front discs at present but the Beetle is light on front brakes and so would take some spirited driving to get heat into those front discs. Course you can overcome this by using something like EBC Green Pads that will still give good initial bite but can handle spirited street driving without fade.

So is it something you'll use or just something you wish to fit for the hell of it? :)


maloo - June 3rd, 2016 at 11:20 AM

I have them sitting in my shed so I was thinking of fitting them for the hell of it! I had thought that they would be better but what you have said gives a diferent picture of the end result.

I have spoken to Todd at Subarugears and only a rear kit is available and he is currently working on a front kit that he thinks will be ready in 2 months but is not sure weather it will fit with dropped spindles and link pin front end.

So I have hit a bit of a wall with it!

However thanks for your advice

Cheers

Mark


psimitar - June 3rd, 2016 at 06:18 PM

The wide 5 wheel bolt pattern is a tricky beast for brakes cos basically the caliper needs to sit behind the wheel mounting plate of the rotor/hub. Due to the depth of the drum brake then a disc kit will invariably push the track width out just because it is barely possible to fit a solid disc brake and caliper within the confines of the original drums width. Vented rotors it is not possible to keep the track width standard so a 2" narrowed beam is needed to stay within the track width.

Brake design is a bit of an art as there's the basic hydraulics that are fairly easy to find a caliper with similar piston area to that of a Beetle but then there is rotor diameter and pad area. The larger the rotor the more torque is applied to retard the wheels rotation plus the larger the pad the more friction is created as the pad material warms up. As the Beetle is light on the front and less weight transfers under braking than a front engined car then too big and the front will lock too easily and the rears will hardly have come into force yet.

So by all means have a look around on the internet as there's a lot of actually physics available to consume and there are many people in the USA, UK and Germany that have made their own kits with good results.

Having a go is half the fun :)


Birdman - June 3rd, 2016 at 09:55 PM

I agree with you regarding the bias issue Mike and on the surface, technically you are correct. But with a lot of assumptions and your not looking at it from the perspective of a Subi converter.
We want to use as much of the good gear we got on that auction bought car or half cut as possible. Including the better brakes.
The rear subabrakes kit only pumps the track 20mm total, Within legal limits and easily overcome with wheel offset.
Im sure you could compensate for front track increase in the hubs.
As for bias, why not run the biggest rears possible and worst case scenario, fit a proportioning valve (non adjustable and remote of course) to fine tune the setup.
You can't just dismiss the concept with absolutes mate.


psimitar - June 4th, 2016 at 06:17 PM

Quote:
Originally posted by Birdman
I agree with you regarding the bias issue Mike and on the surface, technically you are correct. But with a lot of assumptions and your not looking at it from the perspective of a Subi converter.
We want to use as much of the good gear we got on that auction bought car or half cut as possible. Including the better brakes.
The rear subabrakes kit only pumps the track 20mm total, Within legal limits and easily overcome with wheel offset.
Im sure you could compensate for front track increase in the hubs.
As for bias, why not run the biggest rears possible and worst case scenario, fit a proportioning valve (non adjustable and remote of course) to fine tune the setup.
You can't just dismiss the concept with absolutes mate.


Never dismissed it mate. Within reason anything is possible but you do have to take into account the basics such as the Subie MC and caliper piston size and then the VW MC and caliper piston size. I mean the biggest possible issue is the front being over braked due to the bias of the subie setup. As you can only legally fit a compensator to the rear line then this is a tricky problem to overcome. So I never said it couldn't be done but just that you need to do the homework and the maths to see if it's possible :)