# APR Brakes vs HPA Brakes



## Williamttrs (Mar 29, 2013)

My plans to upgrade brakes are a bit down on my list, but I noticed that APR has its VWR 6-Piston brakes on sale in BLUE only for $2200 ($600 discount). I don't claim to know a lot about brakes, at least not compared to many people on this forum. 

I had my eye on the HPA brakes, but they are $400 more than the discounted APR brakes and I cannot distinguish anything that I understand to be better or worse about either. I am lack the knowledge to make an informed comparison.

So here are my questions:

1. Can someone point me to some very specific articles about who makes the best brakes and what makes them the best. 

2. Why are brakes only sold in sets of 2? Why not 4? Do most people really just buy front brakes? 

3. Can my existing front brakes be refitted on my back wheels? 

4. How does a brake like the HPA set save 16 lbs per side? Does that mean per wheel or both the front wheel and back wheel combined? I am assuming it means per wheel since the sets are sets of 2 and not 4. I don't understand how there can be this much savings since the TTRS already uses an aluminum bell. 

5. Is there a similar savings with the APR brake?

6. Are there other manufactures that are significantly better than either of the two I am discussing here? Brembo?

7. Any opinions on how my Sepang TTRS will look with a similar, but not identical blue caliper? Would you go with a contrast like yellow or red?

8. Should I run the existing brakes for 6 months to a year and get some significant wear on them before I swap them out? 

9. How do the stock brakes perform on the track? How durable are they?


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## pal (Aug 16, 2000)

Do you want to change your 6-pot OE front brakes just for a different look? 

To answer some of your other questions, since VW integrates the parking brake with the rear calipers its not possible to retrofit a front kit to the back. If you really wanted a fix caliper kit out back, you may have to figure out how to fit a second smaller caliper for the parking brake. Not an easy task and I don't believe I have seen it done.

For relatively reasonably priced kits, its hard to beat StopTech and Brembo for excellent track performance and a wide selection of brake pads.

Weight savings come from an aluminum caliper vs iron on most OEM fitments (TTRS is already aluminum) and a 2 piece floating rotor with an aluminum hat vs an all cast iron rotor (TTRS already has a 2 piece floating setup up front).


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## Poverty (Feb 17, 2012)

Stock brakes are 4 pot not 6

The caliper is ok, but the discs are ****.

Main weight saving to be had is by the disc design.

The VWR kit works very well


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## Sylvain (Mar 17, 2013)

Poverty said:


> Stock brakes are 4 pot not 6
> 
> The caliper is ok, but the discs are ****.
> 
> ...


It's a little bit more complicated like that, i think all the braking system is ****, not only the disk. I've test stock disk, Tarox disk, a friend test Brembo racing disk, AP disk, all warped after few kilometers.

We have test Pagid RS 4.2 (Bleu), 29/39 (Yellow), black...Performance Friction 01, 08.. Ferrodo DS2500, Cabone Loraine... same problem, so it's not only the rotors.

Still looking for something stronger..


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## Poverty (Feb 17, 2012)

Sylvain said:


> It's a little bit more complicated like that, i think all the braking system is ****, not only the disk. I've test stock disk, Tarox disk, a friend test Brembo racing disk, AP disk, all warped after few kilometers.
> 
> We have test Pagid RS 4.2 (Bleu), 29/39 (Yellow), black...Performance Friction 01, 08.. Ferrodo DS2500, Cabone Loraine... same problem, so it's not only the rotors.
> 
> Still looking for something stronger..


Could be, with stock brakes I warped discs nearly straight away.

Now ive got audi 8 pots on stock discs, and the discs now last for the duration of one set of pads. So everytime I need new pads, i need new discs.

Im going to do the daveb AP disc upgrade next. That seems to work.


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## Williamttrs (Mar 29, 2013)

Poverty said:


> Stock brakes are 4 pot not 6
> 
> The caliper is ok, but the discs are ****.
> 
> ...


I thought they were 4 pot , not 6. 

So what is it about one disk over the other that makes them lighter or heavier? I understand that most normal disks are cast iron and that the best of the best are carbon ceramic, which are massively expensive and about 50% lighter than cast iron. Now I have heard the term "aluminum disks" thrown around and I assume that is only referring to the inner housing right? If so, then how can two disks that use an inner aluminum housing and are both high performance (e.g., stock TTRS vs HPA) have as much as a 6 lb weight difference? Can a "super" high performance disk that is cast iron really weight 1/3 less than a high performance disk that is cast iron?


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## Williamttrs (Mar 29, 2013)

Sylvain said:


> It's a little bit more complicated like that, i think all the braking system is ****, not only the disk. I've test stock disk, Tarox disk, a friend test Brembo racing disk, AP disk, all warped after few kilometers.
> 
> We have test Pagid RS 4.2 (Bleu), 29/39 (Yellow), black...Performance Friction 01, 08.. Ferrodo DS2500, Cabone Loraine... same problem, so it's not only the rotors.
> 
> Still looking for something stronger..


What else could it be other than the rotors and calipers? How can the whole system be junk? Do you mean the lines and the hydraulic pump?


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## Williamttrs (Mar 29, 2013)

Poverty said:


> Could be, with stock brakes I warped discs nearly straight away.
> 
> Now ive got audi 8 pots on stock discs, and the discs now last for the duration of one set of pads. So everytime I need new pads, i need new discs.
> 
> Im going to do the daveb AP disc upgrade next. That seems to work.


How can you warp high performance brakes (even stock brakes) almost straight away? Are you tracking every week? 

Since you are replacing both disks and pads at the each change, why have you not upgraded to carbon ceramic? It seems like you would actually save a lot in the long run, since carbon ceramics are generally rated to last around 100K of street use and 2400K of HEAVY track use, at least that is what I read?


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## Marty (Jul 14, 2000)

I'm by no means a track junkie, but I've had my TT-RS at a few HPDE events on stock brakes with no complains / no issues. I'd imagine you'd have to be a hardcore "pro" to need anything more than stock.


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## trichards69 (Feb 8, 2012)

*loba Discs...*

Try the loba disc upgrade. It's pretty amazing


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## smack_ttrs (Mar 24, 2013)

trichards69 said:


> Try the loba disc upgrade. It's pretty amazing


i like the ap rotors but it looks like they include a bracket as well. 

is this to offset a tt/tts to ttrs rotor diameter or do the rotors have a different offset from the hat design that needs to move the caliper inboard/outboard to line up?

do you run these on your car?


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## Sylvain (Mar 17, 2013)

William, i'm not the only one with this kind of problem, most of TTRS in England too. I think the problem is the ratio 370mmx32, the disk is too thin to handle the temperature. Most of configuration using large diameter disk have 34 or 36mm thickness, never 32.


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## pal (Aug 16, 2000)

Sylvain said:


> William, i'm not the only one with this kind of problem, most of TTRS in England too. I think the problem is the ratio 370mmx32, the disk is too thin to handle the temperature. Most of configuration using large diameter disk have 34 or 36mm thickness, never 32.


That is not true. I have been running the StopTech BBK with 355x32 floating rotors (Z4M Coupe, 3275lbs + me) for over 2 years with 25+ track days on them and they have not warped. I know people running 380x32 StopTech rotors without issues as well.

Maybe its a quality control issue? Are both front rotors warping at the same time? How did you confirm they were warped? Brake judder or vibration could be uneven pad material deposits due to improper bedding and/or due to a lot of ESP and ABS intervention esp on track.


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## Sylvain (Mar 17, 2013)

pal said:


> That is not true. I have been running the StopTech BBK with 355x32 floating rotors (Z4M Coupe, 3275lbs + me) for over 2 years with 25+ track days on them and they have not warped. I know people running 380x32 StopTech rotors without issues as well.
> 
> Maybe its a quality control issue? Are both front rotors warping at the same time? How did you confirm they were warped? Brake judder or vibration could be uneven pad material deposits due to improper bedding and/or due to a lot of ESP and ABS intervention esp on track.


During disk rectification, driver rotor is alway more warped than passenger side one.
Look:

Tarox rotors rectification: values:

- Rotor FL: outer side: 5/10th millimeter, inner side: 2/10th millimeter
- Rotor FR: outer side: 3/10th millimeter, inner side: 2/10th millimeter

Pics:

Rectification tool:


First job, here you can see that the disk is completely warped!!


second job, 2/10th each


Third job, finition:


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## pal (Aug 16, 2000)

Sylvain said:


> During disk rectification, driver rotor is alway more warped than passenger side one.]


Thanks for the details; did not mean any disrespect but rather getting facts. 

Now, Audi apparently uses the same rotor left and right and vanes are directional. That means one rotor has vanes spinning the other way. Can you check if the drive side rotor has the vanes slanted forward? If yea, then its possible that driver side is not dissipating heat optimally.

StopTech rotors have directional vanes slanted back on both sides and hence rotor is optimal on the correct side only.


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## MSS Automotive (Mar 20, 2013)

*DISCLAIMER*: Only commenting from personal experience though I do have a kit in development which I will release in due course.

I used to have the view that the OEM stock discs were not up to the job however I have been privy to others experience so I am now of the view that the whole TT-RS brake system is indeed ‘OK’ for the majority though a change is necessary for the ‘few’.

There are a few of us, and I suspect Sylvain, like me fall in to same category where the stock brake system does not actually work well for us simply because of the way we use the brakes _– think Jenson Button vs. Lewis Hamilton when they were team mates...Lewis always had issues with his tyres wearing out quickly whilst Jenson was smoother than silk - _admittedly over time I have learned to change my braking style...more trailing and less big application works for me.

So, I just think the stock brake system (discs; pads; fluid) works for most and fails for a few.

I had an issue with two sets of the OEM front discs and made a change back in 2010. I have not had any issues with brakes since despite regular track sessions and on one occasion having less than 5mm of pad material left on the PFC01 front pads I had once.

I think if I were on stock brake system and planned to drive aggressively or frequent tracks, I will make the following changes..;

- Fluid – I prefer ENLDESSS though SRF; Motul; Prospeed all offer improvements on OEM in terms of temps they can handle.

- Pads – Pagid; PFC; Carbotech (_noted in order of pricing_) all work well. I have used all and they work well front & rears. Expect some noise and in the case of PFC01, lots of dusts...!

- Cooling – this is an area rarely discussed however there is much that can be done. 

- Cooling – (_have I mentioned this?_) this is an area rarely discussed however there is much that can be done. 

- Cooling – (_Ohh yeah, let me mention it one more time_) this is an area rarely discussed however there is much that can be done. 

I spoke with a person I consider knowledgeable in brake technology about brake issues I was facing back in 2010 and he pointed out that pre-bedded pads was one way of avoiding brake related issues – Yes, I also thought he was making it up however I did take a chance and ordered pre-bedded PFC01 pads...Guess what?...I have had no ‘*warped discs*’ issues since 2010 and I also note that the disc surface is smoother compared to prior. PFC major on pre-bedded pads. Carbotech offer pre-bedded pads as an option. Am not sure about Pagid - I suspect they may offer pre-bedded pads as an option. 

I found the following article relatively useful and note the point under the 'Prevention' section of pre-bedded pads - see http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths.

Anyway, back to OP question...I say define the use then look for a solution. It often starts with having good basic foundation thus...;
- high temp handling brake fluid; 
- improved cooling; 
- better use/application of brakes (_one example is not to apply the brakes when at a stop - use the handbrake...that small change reduces the risk of pad compound transfer on to the rotor surface_).

WB


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## Sylvain (Mar 17, 2013)

pal said:


> Thanks for the details; did not mean any disrespect but rather getting facts.
> 
> Now, Audi apparently uses the same rotor left and right and vanes are directional. That means one rotor has vanes spinning the other way. Can you check if the drive side rotor has the vanes slanted forward? If yea, then its possible that driver side is not dissipating heat optimally.
> 
> StopTech rotors have directional vanes slanted back on both sides and hence rotor is optimal on the correct side only.


Tarox rotors have no directional vanes, only straight tubes, no vanes. I have warped them imediatly during bedding (Pagid blue).
Stock rotors, it's right, left and right vanes have same direction!! I don't remember if it's the left side or right who have reverse vanes.

My last stock rotors has been warped with PFC08 pre-bedded, so no influence for me, but i warped them on track even on the road, good point!

For cooling, i've just install modified Porsche GT3 air duct, i will post some pics here, i think it will help a little bit more than stock Audi air duct.

Brake fluid seems very important too on TTRS, on my last track day at Le Mans, after only 3 laps, the RBF600 motul was in ebullition.
I'll use Castrol SRF as my friend use it on his GTR, it's fine.


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## MSS Automotive (Mar 20, 2013)

Sylvain said:


> Tarox rotors have no directional vanes, only straight tubes, no vanes. I have warped them imediatly during bedding (Pagid blue).
> Stock rotors, it's right, left and right vanes have same direction!! I don't remember if it's the left side or right who have reverse vanes.
> 
> My last stock rotors has been warped with PFC08 pre-bedded, so no influence for me, but i warped them on track even on the road, good point!
> ...


 Sylvain,
care to detail your brake specs...;

I just want to run some numbers on your setup for my own curiosity...am just interested in the following info...;
1) front discs size; rear discs size
2) front pad swept volume; rear pad swept volume
3) front calliper; rear calliper (if these are OEM then state so as I have the specs already else just let me know the number of pistons for front or rear and sizes)

The above info will help me look at the maths to see what I can see. There will not be a ‘magic’ answer...likely just a hint which may help.

IF you are looking at fluid change I would advise you look at ENDLESS RF650 – cost a little more however quality always comes at a price. What I found with ENDLESS RF650 were two key traits...;
1) *Recovery* after use was almost instant thus after a long session on track it only needs a gentle dab on first application afterwards and it comes back to life – assuming you ever get to extend it in the first place. 

2) *Consistent pedal* feel in use...in the 3-yrs of use I have not once managed to get the pedal to lose its firmness on track...and that is feedback from all who have also used the car on track...my car is effectively a development car as we use it to test a range of products I develop. So, it really gets a fair amount of track abuse and has done for the past 51.5k miles...no issues with brakes and I use OEM discs and rotors though cooling parts are my own design which I will release in due course.


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## Poverty (Feb 17, 2012)

Completely off topic, but Jenson no grip button isn't better with his tyres than Hamilton!


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## Sylvain (Mar 17, 2013)

William, all my parts are stock parts exept front pads, brake fluid and air duct.
I'm plan to buy the Loba 8 pistons kit now.


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## MSS Automotive (Mar 20, 2013)

Sylvain said:


> William, all my parts are stock parts exept front pads, brake fluid and air duct.
> I'm plan to buy the Loba 8 pistons kit now.


 OK and thx. I thought you had upgraded discs all round.

LOBA is a great choice and the few people I know who have these are very happy so that should help. I will however choose the brake fluid with care as your experience indicates high usage of the brakes.

Offcourse, the alternative advice would be to SLOW DOWN...which, IMO, would be a 'red rag to a bull'. A sports car is meant to be driven, hard & fast...!

Anyway, imo you are on track with LOBA kits be it engine or brake upgrades. I hear/read nothing but great things about their products...which is where I aim to be with my own line of products...one day...here is hoping...

William


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## MSS Automotive (Mar 20, 2013)

Sylvain,
forgot to mention that I may be going to Le Mans again this year though in August - see http://www.delta-racing.co.uk/events/ - with Delta Racing. 

Stewart and the team who run Delta Racing are pretty cool and if your calendar is clear let me know and we can meet up. There is usually a dispersed group of us from London; Paris and Isle of Man all ending up at Le Mans once a year at least.


The crowd are mostly car enthusiasts – all sorts of machines do turn up and always a blast...!

Stewart usually has a party at the end of each day so it is more than a track event...basically, we track during the day on Friday; party in the evening; sleep it off and start all over again on Saturday then again on Sunday... then make our way home on the Monday...usually in a poor state...!!!


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## Sylvain (Mar 17, 2013)

Thanks William, i just saw the price for the event at Circuit Bugatti: 250£ !!! here in France, the most expansive we paid for this track day is 240€, usually 180~200€ is a good price.


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## MSS Automotive (Mar 20, 2013)

Sylvain said:


> Thanks William, i just saw the price for the event at Circuit Bugatti: 250£ !!! here in France, the most expansive we paid for this track day is 240€, usually 180~200€ is a good price.


Haha...here in the UK, £250 is a good price certainly for me though I know what you mean about the cost of track day events.


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