Brake upgrade/advise

[Tombirch95]

So I had a bit of trouble with my brakes last night, I was driving on the car and fiddle (Matlock to Macclesfield over the peak district) and having not travel this way before I took each turn with caution IE slowed right down, I was using the brake an awful lot due to the hills and corners, and used the engine to slow me on the down sections of the hills, as I was approaching Macclesfield the brakes must have over heated as they where not responsive and did not work as usual and there was a terrible smell. So I found a place to stop and let them cool for 10 minutes then took it easy till I hit Tesco in Macclesfield, checked the brakes and they looks good but where hot (checked with thermal IR camera) so pulled into Tesco and went for a wonder and grabbed a coffee as I still had a good way to go before I got back home.


Let them cool for about 40 minutes then sprayed a mists of room temp water onto the front brakes to which steamed and eventually cooled the brakes, I got back going again but took it easy using the engine as my main source of speed control and trying to avoid using the brakes to let them cool. This worked got back home and checked the brakes out and they where functioning as normal. Driving in them today they are spot on with no issues.

Just wondering if there is anything I should do to improve the brakes to stop this happening again as it could have been a lot worse and I believe I was quite lucky for them to fail where they did as I could stop safely.

I have had the front brakes changed previous to Bosch front pads and discs only having traveled around 5-6 thousand with the brakes.

Should I think of upgrading to vented discs? Any suggestions would be great

Regards

Tom


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[iichel]

you already have vented 256x22mm front discs and 200mm drum brakes in the rear.

with the same size (and mass) of the front disc, you'll have the same amount of heat.
it's simple physics, law of conservation of energy dictates that kinetic energy is transformed into heat by friction.
the energy of the movement will heat up the discs. the only way to avoid this is to slow down to start with or do even more engine braking.

[Tombirch95]

you already have vented 256x22mm front discs and 200mm drum brakes in the rear.

with the same size (and mass) of the front disc, you'll have the same amount of heat.
it's simple physics, law of conservation of energy dictates that kinetic energy is transformed into heat by friction.
the energy of the movement will heat up the discs. the only way to avoid this is to slow down to start with or do even more engine braking.

Thanks for your reply, I wasn’t speeding if anything I was going around 40-50 didn’t seem it safe to do 60mph going even slower around the corners, I was thinking more of the image I’ve attached.

Tom




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[iichel]

ah okay. that's not very fast indeed.
the problem is... or the thing is... if you want to upgrade your front brakes, it would be good to do the rears as well.
and apart from that, it takes some effort since you'll have to replace the hub carriers in the front as well to fit those bigger brakes.

[Tombirch95]

ah okay. that's not very fast indeed.
the problem is... or the thing is... if you want to upgrade your front brakes, it would be good to do the rears as well.
and apart from that, it takes some effort since you'll have to replace the hub carriers in the front as well to fit those bigger brakes.

It was a new raid to me so I didn’t know what to expect so took it easier or so I thought [emoji23] sounds like allot of work to change them to this type, rear are standard drum brakes have thought about changing to discs but have seen much info on doing so.

Tom


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[Ricmondo]

On previous cars much heavier and more powerful than the Polo I’ve found Green Stuff pads are very fade resistant certainly efficient enough to enable you to attack the Cat and Fiddle with confidence.

Relatively cheap and easy solution,

[cheba]

you already have vented 256x22mm front discs and 200mm drum brakes in the rear.

with the same size (and mass) of the front disc, you'll have the same amount of heat.
it's simple physics, law of conservation of energy dictates that kinetic energy is transformed into heat by friction.
the energy of the movement will heat up the discs. the only way to avoid this is to slow down to start with or do even more engine braking.

Thanks for your reply, I wasn’t speeding if anything I was going around 40-50 didn’t seem it safe to do 60mph going even slower around the corners, I was thinking more of the image I’ve attached.

Tom




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A big brake kit like the one in the pic is aimed at those who do hard track driving and want to be able to brake hard from high speeds several times a lap, lap after lap after lap. They can resist high temperature without fading, but the downside is that a kit like that is very expensive and it doesn't make sense to get a kit like that for a car that only sees normal road use (unless you are lucky to find a used kit for a really good price).

A good way to upgrade would be to get factory brakes from a more powerful model, which shouldn't be too hard to find used. Some Polos (at least some GTIs) and some Audi A1 have 288x25mm rotors in front, and bigger calipers. Even better, some Polo GTIs, A1/S1 and the Polo R WRC have 312x25 (sometimes listed as 310x25). Same caliper as the 288mm but different caliper carriers. However (as iichel suggested) I believe that switching to 288mm or 312mm would require you to switch out the hub carriers since the caliper carriers for the bigger brakes won't fit on the hub carrier used with the 256mm brakes.

As for the rear brakes, there are 230x9mm nonventilated rotors which are used on the GTI, but even better are the 254x22 ventilated rotors (I think only the R WRC used these so they are harder to find, also they do not use the same caliper as the 230mm rotors).

Regardless of if you upgrade to bigger brakes or not, you'll want to have good pads. You said that you have had the pads changed, I assume that the new pads are standard "OEM equivalent" pads. These are sold under a ton of different brands, and the quality can be hit and miss. Personally I have switched my front pads since I wanted ones that resisted heat better (for occasional track days) and I chose Brembo HP2000 pads since I have only heard good about them. They cost more than standard pads, but they are said to be very durable and they also perform well also at high temperatures. I don't know if they are available for the 256mm brakes though.

Also, in the VW parts catalogue there exist front brake cooling air guides for the Polo 6R. See my post on this page: https://uk-polos.net/viewtopic.php?f=56 ... rt=105#top
It's a cheap mod (something like 30€ total I think), I have them installed on mine, although I did not perform measurements before and after so I can't say how useful they are. Since you have an thermal camera, maybe you should try it

I also recommend this thread: https://ibiza-forum.de/index.php/Thread ... /?pageNo=2
You may need to use Google Translate, but there's lots of info on brake and chassis upgrades for cars on this platform using OEM VAG parts.

[RUM4MO]

Snip Snip --------
Also, in the VW parts catalogue there exist front brake cooling air guides for the Polo 6R. See my post on this page: https://uk-polos.net/viewtopic.php?f=56 ... rt=105#top
It's a cheap mod (something like 30€ total I think), I have them installed on mine, although I did not perform measurements before and after so I can't say how useful they are. Since you have an thermal camera, maybe you should try it

I also recommend this thread: https://ibiza-forum.de/index.php/Thread ... /?pageNo=2
You may need to use Google Translate, but there's lots of info on brake and chassis upgrades for cars on this platform using OEM VAG parts.

One thing about fitting cooling air guides, will they work well enough if you leave the metal stone guards on the front brakes? Alos do you not also need to vent vented wheel arch liners? I'm only making these comments as anyone on the Audi forums that fit similar bits to the Audi S4, either cut vents in the front wheel arches and fit Porsche Macan air guides, as well as cutting back the front brake stone guards to be the same as RS4, ie just leaving enough stone guard material to protect the ABS semsor and the TRE or some other swivel that has a rubber grease boot that needs protecting.

[cheba]

Snip Snip --------
Also, in the VW parts catalogue there exist front brake cooling air guides for the Polo 6R. See my post on this page: https://uk-polos.net/viewtopic.php?f=56 ... rt=105#top
It's a cheap mod (something like 30€ total I think), I have them installed on mine, although I did not perform measurements before and after so I can't say how useful they are. Since you have an thermal camera, maybe you should try it

I also recommend this thread: https://ibiza-forum.de/index.php/Thread ... /?pageNo=2
You may need to use Google Translate, but there's lots of info on brake and chassis upgrades for cars on this platform using OEM VAG parts.

One thing about fitting cooling air guides, will they work well enough if you leave the metal stone guards on the front brakes? Alos do you not also need to vent vented wheel arch liners? I'm only making these comments as anyone on the Audi forums that fit similar bits to the Audi S4, either cut vents in the front wheel arches and fit Porsche Macan air guides, as well as cutting back the front brake stone guards to be the same as RS4, ie just leaving enough stone guard material to protect the ABS semsor and the TRE or some other swivel that has a rubber grease boot that needs protecting.

As I mentioned, I haven't done any measurements so I don't know how effective they are. But they are installed on the front edge of the suspension arm, and are aimed towards the front half of the brake assembly. On this front half of the brake assembly there is no metal shield, because this is where the caliper sits. On the Macan, the caliper instead sits behind the axle so I guess the metal shield is covering the front half, so I expect the air guide setup to be completely different.

I think what is more important than blowing air onto the rotor is to direct air towards the hub area (actually creating a high pressure area there) so you get a good airflow out through the radial slots in the brake rotor.

Also on the Polo (at least on mine) there is a rectangular opening in the front lower part the inner wheel arch liner. I assume this is to let in more airflow from under the front bumper into the wheel housing.

[CNK]

Also, in the VW parts catalogue there exist front brake cooling air guides for the Polo 6R. See my post on this page: https://uk-polos.net/viewtopic.php?f=56 ... rt=105#top
It's a cheap mod (something like 30€ total I think), I have them installed on mine, although I did not perform measurements before and after so I can't say how useful they are. Since you have an thermal camera, maybe you should try it

Wow, I didn't know about this, looks nice

I found few images:
https://www.drive2.com/l/6664773/
https://www.drive2.com/l/7710661/
https://www.drive2.com/l/1993486/
https://www.drive2.com/l/6474593/
https://www.drive2.com/l/472906824127873221/
https://www.drive2.com/l/6474593/
https://minkara.carview.co.jp/userid/17 ... /37010698/

[RUM4MO]

Snip Snip --------
Also, in the VW parts catalogue there exist front brake cooling air guides for the Polo 6R. See my post on this page: https://uk-polos.net/viewtopic.php?f=56 ... rt=105#top
It's a cheap mod (something like 30€ total I think), I have them installed on mine, although I did not perform measurements before and after so I can't say how useful they are. Since you have an thermal camera, maybe you should try it
Snip ---- Snip ----

As I mentioned, I haven't done any measurements so I don't know how effective they are. But they are installed on the front edge of the suspension arm, and are aimed towards the front half of the brake assembly. On this front half of the brake assembly there is no metal shield, because this is where the caliper sits. On the Macan, the caliper instead sits behind the axle so I guess the metal shield is covering the front half, so I expect the air guide setup to be completely different.

I think what is more important than blowing air onto the rotor is to direct air towards the hub area (actually creating a high pressure area there) so you get a good airflow out through the radial slots in the brake rotor.

Also on the Polo (at least on mine) there is a rectangular opening in the front lower part the inner wheel arch liner. I assume this is to let in more airflow from under the front bumper into the wheel housing.

Yes, I was not thinking clearly about the mounting position of the callipers on Polo versus Audi A4 S4, a very valid point!

[Tombirch95]

Latest update on the brakes, I’ve flushed the system and replaced both discs and pads as it spotted the following:



I wasn’t happy and always had a thought at the back of my head that they where not as responsive as I’d though so they got scrapped and new setup installed


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