Just Another Brake Upgrade Question .........

[Stevie C]

I am possibly looking at fitting VW Golf MK 5 Calipers with 312mm Disks on the front and A3 2.0 Quattro rear brake calipers and 287mm Disks to a 140bhp A3 TDI.

Can anyone see any problems i may encounter with this set up over standard? the TDI is running on 19" RS4 Alloys.

 

[Teejay]

Fitting better pads on standard discs, with refurbed callipers (new seals etc) will give you better breaking than just 'going bigger'.

 

[Teejay]

Incidentally what power/torque are you running?

 

[marriedblonde]

I am possibly looking at fitting VW Golf MK 5 Calipers with 312mm Disks on the front and A3 2.0 Quattro rear brake calipers and 287mm Disks to a 140bhp A3 TDI.

Can anyone see any problems i may encounter with this set up over standard? the TDI is running on 19" RS4 Alloys.

A guy on UKMKiv's did it on his 2.0Tdi golf running 18" rims so I can't imagine you will have any issues with 19" rims.

J.

 

[Teejay]

One of my neighbours is really into his Saabs. They also have ATE callipers (like the TDi does). He has 300+ bhp and is running the standard 280mm GM discs with Ferrodo DS3000 pads and braided brake lines. I've seen him outbreak an identical car (on a race track) which was running 6 pot brembo's.

 

[hatmeow]

There should be no clearance problems even if you are running 18s. I am running 18s with a 6 pot brembo and need to use 10mm spacers.

Your set up sounds like you have upgraded to a GTI / A3 2.0T set up. Should be fine!

 

[Stevie C]

Im pushing just over 200 brake. Car has been revo'd and has non cat jetex system fitted cant remember torque of top of my head. Just wanted something a little better and have gone for this set up as didnt want to get into the whole brembo thing..... from what i gather the 170 TDI has slightly larger disks front and back compared to that of the 140... although i may be wrong.

 

[Crisis]

200BHP from Jatex and Remap? Sounds good. Is that Jatex alot better than the Miltek?

(Sorry off topic!)

 

[Stevie C]

mmm.. meant to be jetex! I went for the jetex has it had the twin tails which suited the Rieger Infinity kit that is also fitted.. looks the biz!

 

[Stevie C]

Is it right that just by changing the carriers you are able to fit larger disks using the same calipers?

 

[Beddie]

Is it right that just by changing the carriers you are able to fit larger disks using the same calipers?

Yeah, the 312mm equipped cars use the same caliper as the 288mm ones, you just need the larger carrier to space the caliper out to accomodate the larger disc :thumbsup:

 

[Stevie C]

So is that the same for the rear?? I want to go up to the 286 on the back end too. i think the early 140TDI 8P has 255??? or something or other discs as standard! Where would be the best place to get the new carriers from?? and any idea on cost??

 

[hatmeow]

I would not suggest larger discs with the same calipers. It only looks better with no significant improvement.

If you need an adapter / carrier to fit the larger discs, it even increases the unsprung weight and reduces the stability of the calipers (technically) which actually makes it worse...

 

[Beddie]

I would not suggest larger discs with the same calipers. It only looks better with no significant improvement.

If you need an adapter / carrier to fit the larger discs, it even increases the unsprung weight and reduces the stability of the calipers (technically) which actually makes it worse...

Seems that the combined expertise and budget of the VAG group got it wrong then mate, perhaps you should drop them an email to point out the error of their ways...

 

[marriedblonde]

Seems that the combined expertise and budget of the VAG group got it wrong then mate, perhaps you should drop them an email to point out the error of their ways...

LOL...Yep your right. You might also want to tell all the mkIv owners that upgraded to bigger discs using the carrier method and saw an increase in braking performance that they are wrong. VW driver mag did the upgrade on their GtiT and said the same...

All those TT's and S3's, anni golf's that also had this fomr the factory all had a cosmetic brake addition and inferior brakes...

J.

 

[Stevie C]

So are we saying that the best bet without spending an absolute fortune on Brembos or the like would be to go as originally planned and fit the VW Golf GTI MK5 Calipers with 312mm discs on the front and Audi A3 Quattro rear calipers with 286 discs on the rear?

 

[Beddie]

So are we saying that the best bet without spending an absolute fortune on Brembos or the like would be to go as originally planned and fit the VW Golf GTI MK5 Calipers with 312mm discs on the front and Audi A3 Quattro rear calipers with 286 discs on the rear?

Yeah mate, good value for money mod imo... noticeable increase in stopping power, relatively cheap and easy to do :thumbsup:

You won't need the GTI calipers for the front though, just carriers, discs and the pads of your choice, for the rear you don't specifically need quattro calipers, normal GTI ones will do fine and are probably much easier to come by..

 

[hatmeow]

Dear Beddie and Marriedblond,

Thanks for your input.

That was what I have always been told and it makes sense to me.... Bigger discs with the same calipers will imporve braking? Since the surface and the pressure from the pots remain the same the contact surface between the pads and the pots should be the same no matter how big the discs are. Unless there is better cooling with the bigger discs, uprated pads, and slots on the discs, the braking should be the same...right??

Please shed some light on this! thanks

 

[Beddie]

Please shed some light on this! thanks

Hiya mate,
You are right when you say that the caliper/pads can not exert more braking pressure on the disc, as it's exactly the same caliper used before and after the upgrade, however..
By fitting a larger disc and the required carrier you are moving the caliper further away radially from the centre of the disc, this allows for more braking 'effort' despite having no increase in caliper size/swept pad area,

Imagine having a car with no power steering, fit a small steering wheel and it's difficult to turn the wheel, fit a larger one and it's much easier, no parts other than the wheel would have changed but you have increased the leverage effect you can put on the wheel...
Having the caliper further out from the centre of the disc works on the same principle...:icon_thumright:

 

[hatmeow]

Ah...totally makes sense now....

And I always thought its just a game that the tuners are playing...you learn something new everyday...

Maybe its time I should have my rear discs uprated...

Thanks! much appreciated!

 

[marriedblonde]

Imagine having a car with no power steering, fit a small steering wheel and it's difficult to turn the wheel, fit a larger one and it's much easier, no parts other than the wheel would have changed but you have increased the leverage effect you can put on the wheel...
Having the caliper further out from the centre of the disc works on the same principle...:icon_thumright:

Good analogy!

J.

 

[devonmikeyboy]

You can also apparently use the the rear 310mm brakes from the R32 as a direct replacement.
http://www.autotech.com/prod_brakes_rrbrakeconv.htm#mk5

 

[Teejay]

Another (more complicated) analagy for why bigger discs are better: It's the opposite of engine torque.

The greater the force applied at a given distance from the centre of movement, the faster the acceleration.
Increase the distance from the centre of movement and a smaller force is required to oppose the same moment.

The other benefit of bigger discs is that there is more metal, so they will heat up slower and cool down quicker. That's a good thing, unless you're running ceramic brakes.

 

[hatmeow]

Stevie, Is your TDI a Quattro?

If it is FWD, can you fit R32 calipers on there?

 

[Stevie C]

No its not a Quattro (4x4) but on first inspection it seems like Golf GTI Front Calipers are same as Audi TDI but red in colour. They must have bigger carriers though to accomodate the larger 312mm Discs. hopefully there will not be a problem with fitting A3 2.0 Quattro rear brake calipers and 287mm Disks to the rear although not purchased those yet.

I had the front De chromed today and fitted the S3 pedals when i got it back.. pics to follow.

 

[Stevie C]

Ok, Have just done the rears too so i thought it a good time to add the pictures,

I finally went for a straight swap of original Discs and calipers for the VW MK5 Golf GTI set up. Used 312mm drilled and grooved on the fron with red stuff pads and OEM on the rear.

While bedding in i had a whole load of squeaks but that has gone now! I must say there is a massive difference in braking... much much better. I had to change the rear splash guards too Again straight from the golf at a cost of £35.. the whole set up was less than £400 thanks to ebay and Ian (sproat 99).

Here are the photos of the set up on the car:

And yes wheels will be getting refurbed!!!

 

[Teejay]

Nice work Stevie.

Looks good and if it brakes better then mission accomplished!


Can I ask what year your car is? I've heard that some of the earlier 8Ps have a different hub and require different discs so you can't do this swap. Interested to see if it is possible with mine.

Cheers,
Tim

 

[Stevie C]

Its a Jan 2004, so really early 8P. I had drama finding discs that would fit over the hub with the right depth (50mm if i remember rightly), i had Tried S3 and TT discs to name a few however, MK5 GTI discs go straight on, I got them from MTEC on ebay. They were slightly cheaper than the EBC 8P discs i originally bought that didnt fit!!

 

[sprout99]

looks very good.....those back brakes look like new !!

:icon_thumright:

 

[Stevie C]

Ian, they are awesome and thanks again, I had to get slightly larger rear Splash guards to accommodate the larger discs but these were onl £35 from VW and again like the whole set up its all VW MK5 Golf GTI stuff less the MTEC drilled and grooved discs and front red stuff pads.

Had a little trouble with brake pedal travel but they are hardening up as they bed in and also from my other thread (brake pedal travel after upgrade) i may of missed the bleed nipple on the master cylinder so going to wait till wednesday and have a look when i get a bit of time... but the set up has made a vast improvement over standard.

 

[JustCharlie]

I've got some new golf gti discs, front and rear for sale if anyone wants to do this upgrade, they've done less than 500 miles. 50 quid.