Ok, well brakes is always a contensious issue when it comes to modifying cars, it is potentially a very costly and pointless exercise. What I would like to try and endeavour to do is to culminate people's own opinions on brakes and upgrading them so a wide variety of issues are covered off and hopefully, we can clear things up for some people.
So, as a few starting points:
Cross-drilled vs. Slotted vs. Cross-drilled and Slotted vs. Standard
Is bigger better?
Why does my car now take longer to stop with the massive 8 piston, pizza tray brakes i just spent $5000 on?
What part of my braking system will make my car stop the quickest / in the shortest distance if I change it?
Should I go for bigger brakes on the 6R?
Re: Should I go for bigger brakes on the 6R?
It's not just about stopping quicker, it's also about how long it will keep doing it for without cooking the brakes.
Re: Should I go for bigger brakes on the 6R?
Bigger brakes does NOT stop your car quicker compared to stock ones.
What bigger brakes does:
a) they are more "informative" and theoretically give more feedback
b) they cant overheat (although its hard to overheat stock ones in you are not on the track)
c) they look cooler
d) they will last you longer (although they are much more expensive so you wont save money)
Thinking about this mod myself, but i might just end up painting supports.
What bigger brakes does:
a) they are more "informative" and theoretically give more feedback
b) they cant overheat (although its hard to overheat stock ones in you are not on the track)
c) they look cooler
d) they will last you longer (although they are much more expensive so you wont save money)
Thinking about this mod myself, but i might just end up painting supports.
Re: Should I go for bigger brakes on the 6R?
Ahh yes, the old question of brakes.
I've had quite a few brake upgrades in my time and so what have I learned.....
I disagree with Lieto to a certain extent, given decent traction a larger set of well matched brakes will stop you faster than a stock set of brakes. The limitation is available grip between the tyres and the road surface. If ABS cuts in on a standard brake set-up then an upgrade brake won't stop you any faster. Where upgrade brakes do stop you faster is where you have a high grip coefficient between the tyre and the surface and ABS doesn't cut in.
Upgrade brakes don't necessarily have to mean bigger brakes. A change of brake pads which have a higher coefficient of friction between the pad material and the disc will brake better than OEM ones with a lower cof, again given that ABS doesn't cut in.
Upgrade calipers need to have a similar volume of movement of the brake fluid to the OEM set-up otherwise you will get one of two things happening....
1) if the volume required to move the pads is lower than oem then the brakes will be very sensitive to any brake pedal travel
2) if the volume required to move the pads is higher than oem then the brakes will need much more travel for the same braking as OEM to be felt.
The idea is to have the overall piston area the same as OEM, but spread out over more pistons to get a better feel and an overall better pad pressure against the disc.
Brake upgrades can still overheat, but you would need to really hammer them on a Polo to do it and I haven't got anywhere near on the TAROX 6 pots I have.
Do brake upgrades need a higher spec brake fluid? - Not unless you are going to drive on track or on the road at 10/10ths everywhere. DOT5.1 fluid is probably overkill for the Polo and a good spec DOT4 fluid would probably be just as good.
The brakes will definitely last longer as Lieto says as most of the pressure is spread over a larger area on both the pads and the discs, so a slower wear rate comes as standard.
Bigger is always better although not really always needed - it is simple physics, the same pressure at a larger distance from the centre of the disc gives a bigger braking force than at a smaller distance. Bigger discs also means better heat dissipation and therefore you keep more of the force for longer.
As for cross-drilled discs, I wouldn't touch them unless you are out for a race/track car. They are more prone to cracking, but give even better heat dissipation.
grooved discs are the way I'd go as they clean the pads better than cross-drilled discs and therefore are a step up from normal discs.
As for your question on the 8 pots Gav, my suspicion would be that the piston area is much larger than oem and so you have to press much harder to get the same pressure behind the pads from the fluid.
I've had quite a few brake upgrades in my time and so what have I learned.....
I disagree with Lieto to a certain extent, given decent traction a larger set of well matched brakes will stop you faster than a stock set of brakes. The limitation is available grip between the tyres and the road surface. If ABS cuts in on a standard brake set-up then an upgrade brake won't stop you any faster. Where upgrade brakes do stop you faster is where you have a high grip coefficient between the tyre and the surface and ABS doesn't cut in.
Upgrade brakes don't necessarily have to mean bigger brakes. A change of brake pads which have a higher coefficient of friction between the pad material and the disc will brake better than OEM ones with a lower cof, again given that ABS doesn't cut in.
Upgrade calipers need to have a similar volume of movement of the brake fluid to the OEM set-up otherwise you will get one of two things happening....
1) if the volume required to move the pads is lower than oem then the brakes will be very sensitive to any brake pedal travel
2) if the volume required to move the pads is higher than oem then the brakes will need much more travel for the same braking as OEM to be felt.
The idea is to have the overall piston area the same as OEM, but spread out over more pistons to get a better feel and an overall better pad pressure against the disc.
Brake upgrades can still overheat, but you would need to really hammer them on a Polo to do it and I haven't got anywhere near on the TAROX 6 pots I have.
Do brake upgrades need a higher spec brake fluid? - Not unless you are going to drive on track or on the road at 10/10ths everywhere. DOT5.1 fluid is probably overkill for the Polo and a good spec DOT4 fluid would probably be just as good.
The brakes will definitely last longer as Lieto says as most of the pressure is spread over a larger area on both the pads and the discs, so a slower wear rate comes as standard.
Bigger is always better although not really always needed - it is simple physics, the same pressure at a larger distance from the centre of the disc gives a bigger braking force than at a smaller distance. Bigger discs also means better heat dissipation and therefore you keep more of the force for longer.
As for cross-drilled discs, I wouldn't touch them unless you are out for a race/track car. They are more prone to cracking, but give even better heat dissipation.
grooved discs are the way I'd go as they clean the pads better than cross-drilled discs and therefore are a step up from normal discs.
As for your question on the 8 pots Gav, my suspicion would be that the piston area is much larger than oem and so you have to press much harder to get the same pressure behind the pads from the fluid.
Re: Should I go for bigger brakes on the 6R?
Ye but whats the conclusion: will it stop a non-gti polo better? I guess it wont 99% of the times, cause stock brakes are just "powerful enough".
or?
or?
Re: Should I go for bigger brakes on the 6R?
The initial retardation of a big brake set-up will inspire more confidence than the OEM set-up and gives a better "feel" for the car when braking. On the road I'd say anything barring the GTI wouldn't need better brakes, but the GTI does need them. Personally if I didn't do trackdays I'd have settled for upgrade pads and discs and left the calipers as standard. With a modified car with over 40% more power than stock, good brakes are a must have. I don't like rear drums either and so would go for a disc conversion, but again, probably not a necessity on a non GTI model.
I've driven some vintage cars with decidedly shocking brakes and there is simply no comparison between even the lowest spec brakes on a new Polo and the brakes on old/vintage cars. ABS/ESP/TC all help a new Polo brake better and ultimately like you say Lieto are "good enough" for what the average motorist would need. I don't consider myself an average motorist as I have a motorsport affliction and just like even my road car to be more than capable of handling any kind of incident.
I beat a mate and a member of another forum to the TAROX 10 pot brakes on the Golf and he is still adamant that the accident in his car would not have happened if he had those brakes on his car instead of me on mine.
The old saying stands in my opinion......" it is better to have them and not need them, than need them and not have them!"
I've driven some vintage cars with decidedly shocking brakes and there is simply no comparison between even the lowest spec brakes on a new Polo and the brakes on old/vintage cars. ABS/ESP/TC all help a new Polo brake better and ultimately like you say Lieto are "good enough" for what the average motorist would need. I don't consider myself an average motorist as I have a motorsport affliction and just like even my road car to be more than capable of handling any kind of incident.
I beat a mate and a member of another forum to the TAROX 10 pot brakes on the Golf and he is still adamant that the accident in his car would not have happened if he had those brakes on his car instead of me on mine.
The old saying stands in my opinion......" it is better to have them and not need them, than need them and not have them!"
Re: Should I go for bigger brakes on the 6R?
Some interesting responses so far, I think I will wait for a few more opinions though before I weigh in 
Re: Should I go for bigger brakes on the 6R?
Best mod ive done to my Polo so far. Just finding wheels to fit over them without spacers that is my main issue.
In the wet, im inclined to agree and say that big brakes will not help you stop any quicker. But on a high tractable surface, where you will not break traction, bigger brakes can and will help you stop faster, while eliminating or reducing brake fade, overheating of fluid and cooking of pads.
In the wet, im inclined to agree and say that big brakes will not help you stop any quicker. But on a high tractable surface, where you will not break traction, bigger brakes can and will help you stop faster, while eliminating or reducing brake fade, overheating of fluid and cooking of pads.
Re: Should I go for bigger brakes on the 6R?
Ok, I might chime in now with the knowledge I have learned over the last few years when doing quite a bit of research into brakes (and why I haven't spent big money on them as yet).
Brakes are heat dissipators/generators. They are there on your car to turn kinetic energy into thermal energy by the use of friction between the pad and rotor (for disc brakes) or the drum and shoes (for drum brakes). To give a fuller write-up of my investigations (and to spare my fingers from typing it all over again!), have a bit of a read here: http://www.vwwatercooled.org.au/forums/ ... 69737.html
Blatent use of deako and hurdy's cars in some of the pics too
Brakes are heat dissipators/generators. They are there on your car to turn kinetic energy into thermal energy by the use of friction between the pad and rotor (for disc brakes) or the drum and shoes (for drum brakes). To give a fuller write-up of my investigations (and to spare my fingers from typing it all over again!), have a bit of a read here: http://www.vwwatercooled.org.au/forums/ ... 69737.html
Blatent use of deako and hurdy's cars in some of the pics too