TT-RS/Golf R master cylinder

[the bruce]

Did anyone go for the TT-RS/Golf R master cylinder?

23.81 mm instead of 22.2 mm GTI. I'd expect a stiffer pedal feel.

[vRSAlex]

Did anyone go for the TT-RS/Golf R master cylinder?

23.81 mm instead of 22.2 mm GTI. I'd expect a stiffer pedal feel.

Only needed when increasing caliper piston sizing through fitting RS4 calipers etc.

[scopes]

What about with TTrs brakes, which are larger 4 pots?

[DFish]

or say AP 6 pots?

Fish

[Hurdy]

Or even stock Golf R brakes - single pot!

My brake feel is firmer than i remember the ED30 being - even on the TAROX set-up, but it is still not overly hard.

[the bruce]

From theory if you increase master cylinder by 15 % you'll get 15 % less pedal travel and
increasesed pedal pressures (by 15 %).

It's not just a question of 'need' but a question of what you want. I want a stiffer pedal feel.

Though a new MC isn't really 'cheap', but compared to 4-pots it's not that expensive at all.

[scopes]

 
Any prices for these?

[the bruce]

piston size/area



1. stock front caliper:


Golf/GTI - Ate FN3 54 mm caliper: 2290 mm²

S3/R32/R - FNRG 57 mm: 2552 mm²



2. aftermarket - proper match:


AP Racing 6-pot CP7068-00 (355x32 ) > 2350 mm²

Boxster: 40 mm + 36 mm > 1257 mm² + 1018 mm² = 2275 mm²

Boxster S: 40 mm + 36 mm > 1257 mm² + 1018 mm² = 2275 mm²

993 Turbo: 36 + 44 mm > 1018 mm² + + 1520 mm² = 2538 mm² (on the edge)

Brembo GT 'A-caliper': 40 mm + 36 mm > 1257 mm² + 1018 mm² = 2275 mm²

Stoptech ST-40: 38 mm + 34 mm > 908 mm² + 1134 mm² = 2043 mm²



3. aftermarket - poor match:


Forge: 707 mm² + 1046 mm² + 1164 mm² = 2917 mm²

996 Turbo: 40 + 44 mm >  1257 mm² + 1520 mm² = 2777 mm²

Q7/Touareg/Cayenne (three variants):

34/36/38 mm : 907.920 + 1017.876 + 1134.115 = ~ 3060 mm²
32/36/38 mm : 804.248 + 1017.876 + 1134.115 = ~ 2956 mm²
30/34/38 mm : 706.858 + 907.920 + 1134.115 = ~ 2749 mm²



4. master cylinder diameter:

- 22,22 mm >  388 mm² (some Mk.V GTI, Mk.V + Mk.VI Golf)
- 23,81 mm >  445 mm² (Mk.V R32, Mk.V GTI, Mk.VI GTI, Golf R)
- 25,40 mm >  507 mm² (RS3 + TT-RS)



If you know the piston diameter: Pi * radius² = area







brake fluids




Make.......DOT Rating.....dry boiling point / wet boiling point


Amsoil DOT 4 - DOT 4 - 580°F (304°C) / 410°F (210°C)

AP Racing 551 - DOT 3 - 527°F (275°C) / 302ºF (145ºC)

AP Racing 600 - DOT 3 - 590°F (310°C) / 410°F (210°C)

AP PRF Racing - DOT 4 - 608°F (320ºC) / 311°F (155ºC)

Ate SL6 - DOT4 + ISO6 -  509°F (265°C) / 347°F (175°C)

Ate Super Blue - DOT 4 - 536ºF (280ºC) / 390ºF (194ºC)

Ate Super 200 - DOT 4 - 536ºF (280ºC) / 390ºF (194ºC)

BMW OEM  - DOT 4 - 446*F (224°) / 311*F (156°)

Bosch - DOT 3 - 491ºF (255ºC) / 288ºF (142ºC)

Bosch - DOT 4 - 509ºF (265ºC) / 329ºF (165ºC)

Bosch - DOT 4+ - 536ºF (280ºC) / 356ºF (180ºC)

Brembo LCF 600+ - DOT 4 - 601ºF (316ºC) / 399ºF (204ºC)

Brembo EVO 500+ - DOT 4 - 520ºF (271ºC) / 336ºF (169ºC)

Castrol GT LMA - DOT 4 - 509ºF (265ºC) / 311ºF (155ºC)

Castrol SRF - DOT 4 - 590ºF (310ºC) / 518ºF (270ºC)

Endless RF-650 - DOT4 -  612°F (323°C) / 425°F (218°C)

GS610 - DOT 4 - 610°F (321°C) / 421°F (216°C)

Gunk HD - DOT 4 - 510ºF (266ºC) / 311ºF (155ºC)

Motul DOT 5.1 - DOT 5.1 - 509ºF (265ºC) / 365ºF (185ºC)

Motul RBF 600 - DOT 4 - 594ºF (312ºC) / 421ºF (216ºC)

Motul RBF 660 - DOT 4 - 617ºF (325ºC) / 400ºF (204ºC)

Neo Super DOT16 - DOT 4 - 610°F (322°C) / 421°F (216°C)

Pentosin Super - DOT 4 - 500°F (260°C) / 338°F (170°C)

Pentosin RBF - DOT 4 - 572°F (300°C) / 392ºF (200°C)

Performance Friction RH665 - DOT 4 - 617°F (325°C) / 395°F (195°C)

Project µ G-four 335 - DOT 4 - 634°F (335°C) / 429°F (221°C)

Prospeed RS683 - DOT 4 - 683°F (360°C) / 439°F (224°C)

TAR•OX Roadrace - DOT 4 - 583°F (314°C) / 401°F (205°C)

ValvolineProSyn - DOT 3/4 - 527ºF (275ºC) / 347ºF (175ºC)

Wilwood Hi-Temp 570 - DOT 3 - 570ºF (299ºC) / 284ºF (140ºC)

Wilwood EXP600 Plus - DOT 4 - 633ºF (330ºC) / 417ºF (213ºC)

[gazbutS3]

Or even stock Golf R brakes - single pot!

My brake feel is firmer than i remember the ED30 being - even on the TAROX set-up, but it is still not overly hard.

wouldn't the increased piston area of the tarox set-up make the pedal softer John on the standard master cylinder, more piston area needing an increase in pedal movement???

[Tfsi_Mike]

What are these found on, Holger?

Brembo GT 'A-caliper': 40 mm + 36 mm > 1257 mm² + 1018 mm² = 2275 mm²

[rex]

On the Brembo BBK Kit (330x28 discs)
As far as I know this is the same caliper as found on Cupra R (1.8T).

[the bruce]

Mike, a (don't remember) Swiss or German Forum member told me. He runs these Brembos on his Octavia RS.

[the bruce]

Some helpful links:

http://www.jakelatham.com/radical/info/brake_calculators.shtml

http://www.jakelatham.com/radical/info/PedalSetup-DualMaster-Guide.pdf

http://www.sae.org/events/bce/daimlerchrysler-gritt.pdf

http://sports.racer.net/brake_bias.htm

http://www.outlawdiscbrakes.com/faq.html

http://www.tceperformanceproducts.com/404.php

[DFish]

AQfter fitting my AP 6 Pots (CP5570's) and found I had a better pedal than with the Cupra/R32/S3 setup fitted. Also found that the ABS kicked in a fair bit earlier, so I've had to re-learn the art of hard braking. ;)

Fish

[the bruce]

What kind pads do you run? AP404?

No wonder the pedal feels firm. It's matched to the R32/S3. The CP7068 kit would provide an even stiffer pedal feel.

 

piston size/area



1. stock front caliper:


Golf/GTI - Ate FN3 54 mm caliper: 2290 mm²

S3/R32/R - FNRG 57 mm: 2552 mm²



2. aftermarket - proper match:


AP Racing 6-pot CP7068 (355x32 ) > 2350 mm² (small bore version of CP7040 caliper for Mk.V/VI)

AP Racing 6-pot CP5570: 27.0 + 31.8 + 38.1 > 573 mm² + 794 mm² + 1140 mm² = 2507 mm²

Boxster: 40 mm + 36 mm > 1257 mm² + 1018 mm² = 2275 mm²

Boxster S: 40 mm + 36 mm > 1257 mm² + 1018 mm² = 2275 mm²

993 Turbo: 36 + 44 mm > 1018 mm² + + 1520 mm² = 2538 mm² (on the edge)

Brembo GT 'A-caliper': 40 mm + 36 mm > 1257 mm² + 1018 mm² = 2275 mm²

Stoptech ST-40: 38 mm + 34 mm > 908 mm² + 1134 mm² = 2043 mm²



3. aftermarket - poor match:


Forge: 707 mm² + 1046 mm² + 1164 mm² = 2917 mm²

996 Turbo: 40 + 44 mm >  1257 mm² + 1520 mm² = 2777 mm²

Q7/Touareg/Cayenne (three variants):

34/36/38 mm : 907.920 + 1017.876 + 1134.115 = ~ 3060 mm²
32/36/38 mm : 804.248 + 1017.876 + 1134.115 = ~ 2956 mm²
30/34/38 mm : 706.858 + 907.920 + 1134.115 = ~ 2749 mm²



4. master cylinder diameter:

- 22,22 mm >  388 mm² (some Mk.V GTI, Mk.V + Mk.VI Golf)
- 23,81 mm >  445 mm² (Mk.V R32, Mk.V GTI, Mk.VI GTI, Golf R)
- 25,40 mm >  507 mm² (RS3 + TT-RS)



If you know the piston diameter: Pi * radius² = area