205 Big Brake Upgrade - Master Cylinder

[Pug Monkey 0]

Hello to all,

 

I am wanting to start my big brake upgrade for my S3 205 as detailed on 205gti drivers. It reads really well and is simple enough but I'm confused about the master cylinder. Mine is just about shagged (standard S3 20.6mm 4 outlet) and would like to upgrade it to the 22mm 4 outlet as described but I can't find any one (in Oz) to help me with what model the thing comes off. Can anyone help me with a model / year / maybe part number.

 

I am going to be selecting the 307 discs and calipers so the bigger master cylinder will help me move some more fluid.

Edited August 9, 2010 by Pug Monkey

[Pug Monkey 0]

After having a quick search i find details of a Bosch 23.8 4 port MC with a part number of LM21007. Is this what I'm looking for and will the 205 fluid bottle fit ok or will I need to buy that too.

 

Thanks for any help here,

 

Mark

[shalmaneser 26]

After having a quick search i find details of a Bosch 23.8 4 port MC with a part number of LM21007. Is this what I'm looking for and will the 205 fluid bottle fit ok or will I need to buy that too.

 

Thanks for any help here,

 

Mark

 

big MC came on most largish engined 406s.

 

Having said that i'm running gti6 callipers with a standard MC and it's fine.

[Pug Monkey 0]

big MC came on most largish engined 406s.

 

Having said that i'm running gti6 callipers with a standard MC and it's fine.

 

Has anyone done the 307 (283mm) Upgrade ? How does it perform over the std 205 S3 Gti ?

[shalmaneser 26]

Has anyone done the 307 (283mm) Upgrade ? How does it perform over the std 205 S3 Gti ?

 

The gti6 setup is 283mm but i think the diameter of the slave piston on the 307 calipers is smaller than the gti6 calis meaning less brake effort at the wheel with the 307 parts. Could be wrong though.

 

Either way, the improvement in braking performance over standard 1.9 or 1.6 calipers is significant.

[pugpete1108 62 1 Cars]

i have just started using the 283 hdi setup and it is waaaay better than std even though it is still not bled properly the difference is night and day.

[Rob Thomson 6]

I absolutely hated the GTi-6 brakes I fitted to my 309 a few years ago; it was simply more brake than the car needed and buggered the pedal feel (even with the 406 MC) and - more importantly - the brake balance between front and rear. I genuinely much prefer the standard brakes of my 1.6 GTi.

 

Brakes are a very subjective thing, one man's meat is another man's poison. You won't stop any faster by fitting big brakes, and you won't get fade with standard brakes (assuming proper pads, not cheap and nasty replacements) unless you've got a lot of power and you're name's Chris Atkinson.

[Tom Fenton 1,541]

I've the 283mm brakes on both of my cars, I like them, BUT, and a big BUT, both cars have twin master cylinder pedal boxes to get the balance right.

[Rob Thomson 6]

I've the 283mm brakes on both of my cars, I like them, BUT, and a big BUT, both cars have twin master cylinder pedal boxes to get the balance right.

 

So did my 309 (for a while) but in hindsight I don't think it was adjusted properly because I hated that too!! Other cars I've driven with bias pedal boxes have been absolutely different.

[CaptainK 11]

You won't stop any faster by fitting big brakes

Huh? I certainly stop a lot quicker in both of my cars now they both have big brake upgrades - 205 has a 283mm GTi6 setup, FTO has a Wilwood Dynalite setup - god knows what size disc they are, but it certainly stop a lot quicker than the original brakes, which are all pants as standard on FTOs.

[oonip 4]

The single most significant performance mod you can do for a road car is the the pad material, leave the master cylinder alone UNLESS you plan on having a method of correcting your brake balance.

 

For track applications however its quite a different story.

 

Nick