# TT-RS Rear BBK review...



## 996cab (Aug 13, 2011)

Hi All.
I thought I should give you initial feedback from the rear brake work that we have done...and this is as follows...have also included some still pix of the car and on track;

(*SHAMELESS PLUG*: Old set up for sale here - http://www.vagoc.co.uk/vb/showthread.php?t=12329 or http://www.ttforum.co.uk/forum/viewtopic.php?f=15&t=308633)

I have just fitted - _in essence, I already had a new set of the Audi RS6 C5 335mm discs so that was the only item not purchased from DaveB_ - the DaveB rear BBK however combined with CarboTech XP10 pads. My fronts are still RS6 C6 390mm BBK with PFC08 pads.

*Reason for the change* was post starting tuition - _about damn time too as I was honestly useless on track once the car was up to scratch and I could no longer blame the car...!!!_ - when it was pointed out to me that the front brakes were too strong and the rears were going light. Pix attached showing the car tipping on its nose tells a good story _(apologise if you have seen this before_). My proposed plan of adding yet more weight to the rear of the car was deemed as too dumb to warrant a response...erm, I was only trying to get the car to a 2-ton weight...never mind...!!!


*Short Review*
*Road Conditions* - wet with a few dry patches especially on the A-roads this test was done on. These roads are close to home and I know every inch of the tarmac very well. This is my 'test ground' as the roads are often quiet with long stretches and lots of bends. Also exhibits the usual road surface undulation (_camber_) that is to be expected of any normal road...it is not smooth like some race tracks.

On hard stop the front dipping has been reduced - I estimate with MagneRide in soft mode the dipping reduction is 25% /// with MagneRide in firm mode reduction is 50%...thus a positive outcome.

There is however a trait now introduced which I will need to undertake further testing - ideally in the dry also - to conclude. The new trait is that the car veers off to the right (_oncoming traffic - *NOTE* that am in the UK and we drive on the proper side of the road..._) ever so gently on hard braking from 60MPH+ admittedly on A-roads with wet tarmac and undulation. I have not tested the brakes this way prior so no comparison to make. It almost feels as though one side of the rears is not effective hence the gentle 'slide' always to the right. Also, the tyres seem to feel at the limit of their adhesion towards the end of the hard brake cycle during the test...again I must emphasis that these tests are OTT and in the wet...offcourse, I would normally not use the car this way.


*Other useful info*
- I have attached a pix below with a table charting the brake maths from OEM(_1st pix in the row_) to current (_4th pix in the row_). The 5th pix_ in the row_ is a DaveB solution which I may go to as a next step...if necessary post my track tests. I use the maths as a guideline and from OEM to my last setup (_3rd pix in the row_) the maths indicated the fronts was too strong and that was reflected in the use of the car.

- Tyres are almost new with, an estimated, 7mm all round. 

- The rear 335mm BBK is the only change, brake related work, done on this visit. The fronts are RS6 C6 390mm OEM with PFC08 pads.

- The kit was fitted by my regular tuner - JKM.

- I probably need to re-do alignment all round as JKM found the SuperPro front bushes were damaged after 40k miles so a new set has also been fitted.

- The PFC08 pads on fronts have seen 1200 road miles and 3 trackdays - estimated 75 laps - use to date. 

- The CarboTech XP10 pads (_I had these painted black on fitment to the car to keep the theme of the car, which is OEM...besides, the red is a touch wild...!!!_) - I suspect - need further bedding in. Interestingly, I found the PFC08 to be very 'grabby' at first until a few miles on roads plus track and now they are smooth on first application grabbing harder during the braking cycle...exactly why I changed to them from PFC01 which were just too strong/grabby all the time. 

- I measured cooled disc temp and got 35ºC on the front discs and 25ºC on the rears. These temps were taken after a 30-mins drive with the last 15-mins being at below 40mph.


*INITIAL CONCLUSION*
Overall, the brake change has been a positive step for what I set out to resolve - thus stop the front from dipping on hard braking which caused the rears to go light. The gentle slide issue I have now introduced as noted above is one I need to do a little more investigation to be 100% certain as to whether there is an issue that needs to be resolved. 

I think the reason for the new trait could be various and as follows...;

- post the replacement for the front SuperPro bushes the car could be out of alignment - am thinking camber here as the car did not exhibit the usual 'planted' feeling...then again it was wet as noted above.

- tyre PSI may have dropped especially on the rears...the temps have been cold here lately and I always found the PSI dropped when the car sits around for a week or so as has been the case...car was on track the Saturday before being dropped off to my tuner the following Monday...offcourse the cold PSI always drops after a trackday and then being parked up for a week also contributes to further drop.

- new XP10 pad needs to be bedded-in properly to loose some initial 'grabby' it may have on the rears. This is an assumption and I have no facts to back that up though both front and rear tyres seem to come to the limit of their adhesion earlier than before as I can feel them squirm - ABS is not activated nor does TC/ESP cut in (_I did not observe any warning lights on the dashboard_).

- I may need to 'adapt' my braking from the heavy right foot on the brakes to perhaps being a little gentle on the pedal...??? I had to adapt my braking when changing from OEM to PFC01 + RS6 C6 390mm BBK...a heavy right foot caused the car to dip excessively so a change is nowt new for me.


*UPDATE 22nd Dec 2012*
I was a little restless so took the car in for the alignment to be checked and it was out as expected - see pix attached. Mainly *TOE* front and rear were out and that also put *THRUST* out...that may account for the braking issue...I need to do more research to understand that. Not sure what effect *TOE* being out would have on braking stability though. Anyway, I have had the settings changed back to my desired and car now feels planted as prior.

Braking from 55mph (_I could not go much faster as the rain was heavy at times and road surface was a touch too wet_) car felt safe and stopped in a straight line. I luv the new sound of the rears as the brakes start working...a quickening rumbling noise can be heard...and judging by the temps below it certainly is now working. Am so looking forward to some serious tests on track. 

Naturally, if the brakes become an issue that can not be fixed then I will revert back to OEM...we shall see and I will offcourse report back my findings as I would prefer to be transparent. So for now the rear BBK is fine braking hard from 55mph in the wet - am talking very wet roads mind - the veering off to the right occurred when braking in the wet from 60MPH+...something I would ordinarily do on track so am anxious to put this issue to bed. ASAP

Also checked the following...;

*TEMPS*
FR & Re callipers - 50ºC after a 45-minutes drive though in appalling rain and passable road floods.

Front discs 45ºC
Rear discs 35ºC

FYI, I bought this item to measure temps and it works well - see http://www.amazon.co.uk/Infrared-The.../dp/B0037AWFQW.


*TYRES*
Fronts were 31.5PSI...I put these back to 30PSI which is my preference.
Rears were 26.5PSI...I put these back to 26PSI which is my preference.


*UPDATE 27th Dec 2012*

Well,
there is nowt like testing.

I have been out for extended testing and there is nowt wrong with the brakes in the dry or on damp tarmac. I can only imagine I was a little too aggressive on my first testing. 

This is what I did on this test...;
- Geo the car to my best specs.
- Dropped the rears by 5mm - should have done this before Geo...anyway, we are changing MSS over so we have to Geo again later anyhow.
- warmed the brakes up properly with repeated stop start from high speed down to a standstill.
- with the warming of the brakes, I got the front temps to 220ºC each side and rear temps to 106ºC each side.
- went on one of my fav roads which was damp and wet in places...drove like I was possessed purposefully late braking.
- brakes were superb front and rears with Sports mode on and Off. 
- car pulls up in a straight line even when am standing on the brakes...managed to activate ABS a couple of times as I had that rumbling feel from the pedal under my foot though no lights were on looking at the dash.
- the car really hulls back exceedingly well...we talking seat belt tightening stop.
- car marginally dips to the front though not as bad as before...the front dipping was the reason for the change as previously reported.

So, the issue reported earlier may have simply been that the rear pads being new were a little grabby. I expect them to lose that grabby feeling even further once I track the car a couple of times. These pads are CarboTech XP10 with operating temps from 121ºC to 898ºC so I was not even in the temp range though they worked very well. 

*TYRES* - the PS2 tyres are at their limits with these brakes as I can tell they are struggling to stop the car as the tyres squeal and 'skip/wiggle' around.


*FINAL CONCLUSION*
These are brakes alright...phenomenal indeed and I hope to report back during the course of 2013 as I give them some treatment on track.


*RATINGS (*objective offcourse...!*)*
So if I were rating these in terms of deceleration I would mark them as follows...;
- Now with XP10 pads + 335mm discs and PFC08 fronts 390mm discs = 8/10. I feel I can do better with better tyres than the PS2 hence only an '8'. So the new issue is limitation of the tyres. 

- Previous with RS19 pads + 312mm OEM discs and PFC08 fronts 390mm discs = 5/10. 

- Previous with RS19 pads + 312mm OEM discs and PFC01 fronts 390mm discs = 6/10 mainly due to the fronts being so powerful so they stopped the car better. 

- Previous with OEM pads + 312mm OEM discs and DS2500 fronts 390mm discs = 4/10. front pads died after 5k miles...was better than OEM.

- Previous with OEM pads + 312mm OEM discs and OEM fronts 370mm OEM discs = 2/10 - waste of time for the way I use the car. These were just not fit for track though great on streets.



*PIX*


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## hightechrdn (Dec 9, 2011)

Thanks for the great post, as always! 

Can you clarify what hardware is in the rear BBK? RS6 335mm vented discs, but what caliper?

Also, do you happen to know if DaveB will ship to the US?


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## 996cab (Aug 13, 2011)

hightechrdn said:


> Thanks for the great post, as always!
> 
> Can you clarify what hardware is in the rear BBK? RS6 335mm vented discs, but what caliper?
> 
> Also, do you happen to know if DaveB will ship to the US?


Hi,
kept the TT-RS OEM callipers on the rears as they are more than adequate even for rally - a guy in Oz uses his car in rallies and does well see http://www.youtube.com/watch?v=lUA41hFkuYU
- use or serious track use as I do also pad fits almost over the disc height. 

DaveB will ship to US I suspect email him at [email protected].


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## crackkills (Mar 10, 2007)

So let me get this straight. Those are c5 RS6 front rotors or rear rotors? No other modifications needed? Just take the rear rotor off and slap the C5RS6 rotor on and off I go?


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## 996cab (Aug 13, 2011)

crackkills said:


> So let me get this straight. Those are c5 RS6 front rotors or rear rotors? No other modifications needed? Just take the rear rotor off and slap the C5RS6 rotor on and off I go?


Hi,
Thx for reading...you are probably right as my post is not clear as to what my setup is, allow me to indulge...my setup is as follows...;

*FRONTS*
RS6 C6 (_5.0L V10 version_) 6-pot calliper / 390mm x 36mm (_discs & callipers_); 
- needs new brackets (_my tuner got a local machine shop to make this up for me for the 6-piston calliper_); 
- disc spacer (_10mm - my tuner also had these made for me_); 
- Spigot Rings (_aka Centre Rings - used to ensure that the alloy wheel is correctly centred on to the hub_); 
- we re-used the TT-RS OEM dustshield.

For the fronts I went for PFC01 brake pads (_too strong_) then when they died changed 'down' to PFC08 pads (_fantastic pad compound which is strong enough for track & street use, produces less dust and noise_). Offcourse, we have the braided lines; upgraded fluid (_ENDLESS RF650 - what else...!!!_); cooling 'thingy' from Audi though I have another solution in design to fit & test soon. 


*REARS*
RS6 C5 (_4.2L V8 version_) 335mm x 22mm disc ONLY (_disc is ideal as the OEM Calliper can be retained_); 
- needs new brackets (_supplied by DaveB to relocate OEM calliper due to larger discs_); 
- Spigot Rings (_aka Centre Rings - used to ensure that the alloy wheel is correctly centred on to the hub_); 
- we re-used the TT-RS OEM dustshield.

For the rears I went for CarboTech XP10 brake pads however instead of the default 46mm pad height, I asked for 52mm pad height mainly to reduce the unswept area you note in pix supplied - so it was an aesthetics reason. The review above gives my view of them thus far...will test more on track then feedback. Again, we have braided lines too - which can be seen in pix above.

Previously on the rears, I had OEM sized (_312mm_) drilled discs and uprated pads thus RS-19...this was done when we initially changed the fronts to the 390mm disc and PFC01 pads. The combo worked well however, as noted above in my review, the PFC01 were too strong and the RS19 were too weak hence I noted that the rear of the car went light on hard stop with the nose dipping forward as seen in pix attached above. I also started educating myself to understand more about front / rear brake ratios using calcs and the maths made it obvious where the issue was...the rear brake torque was too low thus with not enough braking torque the car was front brake heavy...so my new setup increased the rear torque by 50% (_from 2333Ibs to 3490Ibs_) and BINGO...there was the answer...as per my review above...!


Wherever possible I will look to use Audi OEM - they have an extensive range and in real terms there is always a solution - tried & tested - that should meet all requirements hence I look within the Audi range first before going aftermarket. 

All of the above brake changes (_done over time - the rears are the last item to be completed recently_) allows me to track the car with no brake related issues thus it stops the car in a shorter distance without any overheating or fade issues unlike the OEM...it works very well on street use with higher than OEM initial bite and during the braking cycle that bite gets stronger...also produces far less noise or dust so a win all round for me...though the wallet protested like a spoilt child from start to finish...yep, as I do to my kids when they whine...I pretended I had sudden deaf syndrome / aka selective hearing...!


*MORE PIX...of fronts; old rears fitted & laid out on floor just replaced (*_with yellow pads_*); back view of current rear with TT-RS dustshield; RS6 C5 335mm on floor (*_not mine, just pix I grabbed on NET_*).*


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## hightechrdn (Dec 9, 2011)

Thanks for the clarifications. Great to rear real world feedback on these modifications vs vendor claims which one always needs to be concerned with bias at a minimum.

I sent DaveB an email and will see what he has to say.


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## 996cab (Aug 13, 2011)

hightechrdn said:


> Thanks for the clarifications. Great to rear real world feedback on these modifications vs vendor claims which one always needs to be concerned with bias at a minimum.
> 
> I sent DaveB an email and will see what he has to say.


You are welcome. I have also sent DaveB an email directing him to this link so hopefully he will get in touch soon.


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## crackkills (Mar 10, 2007)

Got it. thanks so much. How do I source that bracket for the rear caliper and do you have a picture of that along with the ring to center the rim onto the hub? 

It drives me bonkers looking at the car and having drilled fronts and solid rears. Makes me feel like a kid that couldn't afford the good rotors for the rear! :sly:


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## 996cab (Aug 13, 2011)

crackkills said:


> Got it. thanks so much. How do I source that bracket for the rear caliper and do you have a picture of that along with the ring to center the rim onto the hub?
> 
> It drives me bonkers looking at the car and having drilled fronts and solid rears. Makes me feel like a kid that couldn't afford the good rotors for the rear! :sly:


The DaveB kit comes with all you need to install and go.

For Spigot - see http://www.autoinparts.com/Wheel_nu..._Aftermarket_Alloy_Wheels/c628_897/index.html.

*PIX of rears and DaveB bracket...*
3rd pix shows the bracket (silver item) which the calliper is now fixed to. Where the brackets fit used to hold the calliper.


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## JohnLZ7W (Nov 23, 2003)

Interesting, so it doesn't just move the caliper out but also upwards a bit. Does that mean you don't need to mess with the ebrake cable routing at all?


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## R5T (Apr 7, 2010)

996cab said:


> The DaveB kit comes with all you need to install and go.
> 
> For Spigot - see http://www.autoinparts.com/Wheel_nu..._Aftermarket_Alloy_Wheels/c628_897/index.html.
> 
> ...


So and how do we contact Sir DaveB. ???


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## 996cab (Aug 13, 2011)

JohnLZ7W said:


> Interesting, so it doesn't just move the caliper out but also upwards a bit. Does that mean you don't need to mess with the ebrake cable routing at all?


Yes it does John and am glad you mention that as most people do not mention that post their install nor take note. 

We looked at a bracket to just move the mounting hole backwards by 11.5mm _(that is the additional increase in size of the disc from 312mm to 335 mm /// remember this is radial increase so the difference in size when you do the subtraction must be divided by 2...!)_ however there was not enough space to do so hence we also settled for the DaveB brackets.

Also, car does not have electronic handbrake (_aka e-brake_) as in RS6 V10 for example else this would have been a little trickier. Install is however a little 'tight' as the handbrake cable must be re-routed correctly else it will touch back of wheels. This is a mod that I would leave to a tuner or work with a tuner.


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## 996cab (Aug 13, 2011)

R5T said:


> So and how do we contact Sir DaveB. ???


DaveB - [email protected].


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## 996cab (Aug 13, 2011)

*Update after track session*

OK, I have had the long awaited opportunity to test out my new rear brakes - see http://www.ttforum.co.uk/forum/viewtopic.php?f=19&t=318058. This update is worth reading if you want effective solutions that works first time on track.

*DISCLAIMER*
Although I know DaveB - never met him just have had dealings on forums like most people - this is an objective review on track of his rear BBK that I bought at RRP thus no discounts; no special treatment; am just a paid up customer.

In other words am not in any one vendor or manufacturers pocket nor am I their puppet...that, imo, is important to remain impartial...  

*OBJECTIVE*
By now most readers of my post will be aware that I give the level of details that should help others make an informed decision...I do not do "_IT WORKS BECAUSE I SAID SO...!". _.

Instead, I give thorough details; comparisons; data; facts; pix to support any assertions made. It is then down to the reader to make an educated decision based on *my views*. Am not paid or funded by any of the vendors or manufacturer of the products I have fitted to my cars. Every product is carefully researched ahead of a purchase - I used to buy everything based on a few words by others who I now know had hidden agendas hence am now a little more thorough in selecting products. Suffice to say, some of those purchases were just a money wasting exercise for me...it's OK, can't take it with you so might as well spend it ehh!!!

When you read one of my reviews you are left in no doubt what I did, why I did it, the cost (_where it is possible to reveal - 'ers indoors reads my posts you know...  _), what benefits it brings. These all help others make an informed choice.

So, it is that I wanted to move brake bias rearward having identified an issue as noted in my opening post.

*So, what is the rear BBK like on track?*
Few words needed here - composed under late heavy braking at Brands Hatch.
Approaching the end of the straight which then falls away in a steep downhill sweeping to the right, am told the trick to getting that corner right is brake as late as you can though in a straight line staying as far left as possible then off the brakes just past the pit exit sweeping the car to the right gently...if you brake too early you don't carry enough speed for the uphill climb...brake too late and you end up in the gravel as the track falls away downwards...so you really need a brake setup that does not upset the car and gives maximum confidence to brake as late as you dare...my biggest issue with my previous rear - which was upgraded on OEM - was that it still left the fronts doing all the work and approaching that corner the car always felt rear light. 

At Brands especially I always kept TC/ESP on as it helped the car remain stable...not yesterday...I switched these off totally and they remained off all throughout the 60-laps I completed...car is very stable as per the video under heavy brake...something I could not achieve in past track day session at all tracks...and at Brands braking late as I did at end of the straight, I found that in the past I could easily unsettle the car with wobbling rears being the end result.

The DaveB rear BBK kills that rear going light *DEAD*...! It does this by moving more brake bias rearwards through the combination of these two key changes...;
- calliper moves the pads towards to the top edge of the disc thus allowing greater pad pressure to be applied to the disc which helps stop the car in a shorter distance. Add an aggressive pad and this change is then very effective as I found.

- the disc size is increased from the stock TT-RS OEM 312mm to Audi RS6 C5 335mm discs (_*NOTE*: stock TT-RS OEM Callipers re retained_). These disc, my understanding, a sided thus helps with disc cooling; also the material is a little tougher thus on the rears it requires longer bedding in procedure...also means you can really use aggressive pads to move more brake bias rearward...exactly what I did.

The rear BBK works exceedingly well in the dry however it is not a full test thus not a '*YES*' from me yet..Ohh no! I want to use it on more tracks and also in the wet with TC/ESP off. I want to prove conclusively that the kit is the real deal...thus far I have no doubt it will pass a wet track session with flying colours but as you all know am more interested in facts.

So, the kit is excellent in the dry and receives a full recommendation from slow mo here. I like it that much that if it performs just as well in the wet then I will be providing this kit as part of the MSS handling 'package'.

Ehh, MSS handling package...what is that then Will? Oops, should have kept that under wraps...more when it is all setup and ready to go...bit too early to shout about it now...!


*Some Stats of interest...;*
- Front Callipers: got to 150 degrees Celsius ; disc got to 300 degrees Celsius (pads are PFC08)
- Rear Callipers: got to 130 degrees Celsius ; disc got to 200 degrees Celsius (pads are CarboTech XP10)


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## hightechrdn (Dec 9, 2011)

Great post as always William. One small issue... The famous Dave B never replied to my email nor are there enough details to replicate the setup without re-engineering the parts. Of course the hard work of finding the best disk and the general shape of the relocation bracket can be seen, but this isn't a case of picking up the phone/email for us in the US, it seems. Any direction on how to obtain the custom parts? Or should I try emailing DaveB again?

Thank you!


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## JohnLZ7W (Nov 23, 2003)

FWIW, 034 is working on a similar setup.

Sent from my Nexus 7 using Tapatalk HD


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## MSS Automotive (Mar 20, 2013)

Quick update...;

rears working just fine with minimal wear and the unstable issue which was still there when I had the RS-19 on the rears though OEM sized drilled discs (rotors) is now banished. 
Braking very late still ends with car stopping in a straight line.

After a few track days now am happy with the whole brake setup. 

What am now working on is heat management so I want to reduce front heat temps and slightly increase rear heat temps. I just think the balance should be closer than the current over 100 degrees centigrade difference...a 25 degrees drop in difference in my opinion would be just right.

pix from last track day...fronts and rears are now on 5k and 4k miles respectively and counting...;

*
FRONTS*








































*REARS*
































*DUSTS Comparison front to rear* (_different pad brands however_)

*FRONTS *after a whole day on track with PFC08 pads on RS6 C6 390mm discs and 6-pots.












*REARS *after a whole day on track with Carbotech XP10 pads on RS6 C5 335mm discs though 2-pots of TT-RS OEMs.


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## hightechrdn (Dec 9, 2011)

Looks like the front rotors are starting to crack at the drilled holes. Are you concerned about rotor failure? Or are the cracks considered superficial at this point?


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## R5T (Apr 7, 2010)

The front brakes look terrible.


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## carl44 (Nov 23, 2012)

All drilled rotors crack with track use. What Porsche says is as long as the cracks don't connect or go to the edge is normal. that's why nobody races with drilled rotors. The GT3 i had the rotors would crack in 400-600 track miles. carl


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## MSS Automotive (Mar 20, 2013)

carl44 said:


> All drilled rotors crack with track use. What Porsche says is as long as the cracks don't connect or go to the edge is normal. that's why nobody races with drilled rotors. The GT3 I had the rotors would crack in 400-600 track miles. carl


Listen to him because he speaks from 1st hand experience...

Indeed years back these disc would have been discarded and a new shiny set would be on the car. With more 1st hand experience now, I tend not to be as dramatic as R5T...what you see on mine is perfectly OK and drilled discs do indeed go through phases when you actually use the car. You just need to have 1st hand expereince to know enough to not be swayed by NET views.

So, at this stage the car will comfortably manage another 10k miles of hard use as per norm. 

The next set of disc will receive Cryo treatment and then we will use and abuse them as per norm and feedback.

Again, I guess a picture tells a better story – below is the last front discs which lasted 22k of similar hard relentless abuse though using the much more disc punishing thus aggrieve PFC01 pads.

Picture taken on 15th Sept 2012 at the time the PFC01 pads were down to 3mm. The car was then used on track at Castle Coombe on 10th October 2012 - see https://www.youtube.com/watch?v=_btDTIMbIaE. No dramas at that point, if you listen to the end of the footage Jim remarks about leaving me some brakes to get me home...he completed another 50 hard laps before the end of the day and I drove home with no issues...plenty of brakes left... 

On that day the car was used as we usually do on track - all day on track testing as per norm no dramas and the BBK performed very well. The discs and PFC01 pads were replaced at the end of October having covered 22k miles of hard use and the current discs went on with new PFC08 pads.

If the pads still had life in them, we would have kept using the disc below until the pads died...we have found the PFC01 pads to last 22k of hard use so that is the benchmark - they were replaced with 2mm left. 

A point to note...the disc below have ripples on the surface due to the harsher PFC01 pads which generates more heat in operation compared to the PFC08. The PFC08 has kept the surface relatively smooth over 17k miles of which we track frequently.

We collect all these data to be better informed and also to give people a 1st hand view - no need going by myths. 

So R5T, relax, we know what we are doing and just prefer to get info on the ground so the current discs are in good shape and NO, it does not look terrible, it looks perfectly OK and good for another 10k miles use...in our opinion.


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## carl44 (Nov 23, 2012)

22k on rotors is amazing with track use. how many track days? carl


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## MSS Automotive (Mar 20, 2013)

carl44 said:


> 22k on rotors is amazing with track use. how many track days? carl


 Conservatively, 20 track days from 2010 to 2012 and each visit we conservatively do 50 laps so 1,000+ track laps I guess. 

I will have to go through my posts at VAGOC to count the numbers however 20 would be a minimum...at a guess likely 25 track days over the 2-years.

For us the key point was that the disc would have fared better on a less aggressive pad than the PFC01 hence we have high hopes for the PFC08 currently on the car and looking at over 30k miles with these thus a change likely towards end of next year.

The main difference today with the track session though is that the car is driven harder - no, not by slow mo here - but by Nick and Jim so the pads and discs are getting a good and honest workout.

We are just taking note as much as we can and are learning lots about braking so should help when we get a kit out next year.


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## MSS Automotive (Mar 20, 2013)

*Gentle bump*

Gentle bump as there are info in this thread that, may be of interest to those considering brake upgrades...

To add to above, am still on same cracked front rotor and these have now seen another 7k since my last reporting thus 12k miles total and the cracks are as before...looks alarming however regular inspection, front & rears, indicates we are OK for now. They will certainly survive pads full life. The PFC08 pads are 50% worn so we are looking at these surviving another 12k of hard use...we shall see.

The rears have also done 7k since last reporting thus done 11k miles in total now with the XP10 pads and the 335mm RS6 C5 discs (rotors). Looks great also and the XP10 pads have worn from 12mm down to 10mm...yeah, these will be going for a while to come.

I want to try out Cryo (frozen) rotors next just to satisfy myself of the myths; claims; scare stories etc...we shall see and I simply luv experimenting...so much can be learned that way to gain 1[SUP]st[/SUP] hand experience.

Pix below...;

*Current mileage* – photo just taken;










*Fronts* – photo taken a couple of days ago;



















*Rears* – photo just taken;




















William


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## hightechrdn (Dec 9, 2011)

Are the caked full holes in the front rotors "normal" based on your usage? Looks like they aren't helping with cooling at all now...


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## R5T (Apr 7, 2010)

The holes are to small, know someone that had them made larger by a metal shop to 7mm, problem solved.


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## MSS Automotive (Mar 20, 2013)

R5T said:


> The holes are to small, know someone that had them made larger by a metal shop to 7mm, problem solved.


Hperformance sell 7mm holed rotors which I looked in to once however the lead time put me off.


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## MSS Automotive (Mar 20, 2013)

hightechrdn said:


> Are the caked full holes in the front rotors "normal" based on your usage? Looks like they aren't helping with cooling at all now...


I do jet the wheels/rotors thus holes off however pix taken is after last track day on 12th Oct and I have not cleaned the car since. Next track day is end of November and I will go through my usual routine which includes jet washing the wheels/rotors.

Doubt if the holes actually contribute to cooling else all the plain rotors would be having real major issues. I just think the holes are for looks at best.

The looks of the rotors do not correlate to the current braking performance. The brakes are still very strong and each time I inspect the rotors I keep thinking to myself it really looks worse than I feel when slamming in the brakes from 130MPH to below 50MPH...either way am running the PFC08 pads to the backing plate...so another rt5mmm to go...easily 10k miles to do


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## sentari (Dec 4, 2011)

William, mine are crypto treated... Frozen Rotors is a few miles from me so I thought to do with with my BBK... I can't so I pound on them, but they appear new still... But i'm going in next week to review a bit of shaking on braking...


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## MSS Automotive (Mar 20, 2013)

sentari said:


> William, mine are crypto treated... Frozen Rotors is a few miles from me so I thought to do with my BBK... I can't so I pound on them, but they appear new still... But I’m going in next week to review a bit of shaking on braking...


Thanks for that feedback. I have read so much about Cryo of rotors and there is much that makes sense as to why they may make a difference and there is also equally ‘scare stories’ of rotors prematurely cracking/wearing etc.

What is for sure though is that those who use it quietly continue to use it as they simply do not want to get involved in the ‘_arguments_’ and it would appear that those who have much to say often base their views on 2[SUP]nd[/SUP] hand info.

I wanted to try them on the last rotor change however we just run out of time and I had to go with plain rotors. I will certainly try them next as I have proven the rotors do crack with the current and previous rotor so the next same Audi OE 390mm with Cryo treatment would be a good testing to see how Cryo rotors fare.

The good news is that my once mediocre driving skills on track has improved markedly – a good 4-sec a lap quicker on comparative tracks this year so am either getting quicker from improved driving skills/tuition (_Honest Sir!)_ or the upping of the brave pills is clearly working. Might double the brave pill dosage for next year anyway just to be sure...

On a serious note ref Cryo, I read that a number of the GT3/RS guys on the Rennlist forum use it and they note a marked increase in rotor life...keep in mind that these boys & girls tend to play hard on track – Sebring for example is reputed to be one of the toughest track on brakes and those who used Cryo rotors on the got more mileage..._that is the only benefit am interested in and one that can be proven_. Increased rotor life with same level of cooling means we can get away with not have a more efficient front rotor cooling if Cryo does indeed make a difference...hence it is of interest.

As with everything else, 1[SUP]st[/SUP] hand experience counts for more than anything else so I will Cryo the next rotors to form a view. One thing is for sure, In my experience, we note that new rotors start cracking after just 2 Trackdays so it won’t be long to wait in proving if Cryo makes a difference or otherwise. If it does then great as it means I will get more than the current 20k+ miles per front rotor & pad combo. If I can increase that to 30K miles of hard track and road use then Cryo is worth it. We will certainly know early on if it does make a difference as I have records of rotor and pad wear from each Trackday we do.


What is my view ahead of testing? Well here goes...;


the science sounds plausible; 
the process is used in some manufacturing anyway; 
am not 100% sure if, effectively, subjecting the metal to same process twice thus during initial manufacturing and sometime later post manufacturing if that would make a difference; 
I have read enough about why it is termed as ‘_snake oil_’ and equally testaments from government departments; transport organisations; race teams all assert that their rotor replacement had decreased post Cryo treatment; 

Got to be worth a trial at the very least to form a view...!


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## 996cab (Aug 13, 2011)

*45k on Rear BBK and counting...*

Been a while since last update. For now just a summary update - with more later when I can find a moment. Will also include pix with the longer update.

- Car has covered 45k miles - streets and track - since the rear BBK.
- Track mileage is estimated at 7.5k of the 45k (75 track days at 100 miles on average / 50 laps per track visit).
- CarboTech pads are half worn thus 6mm left.
- Rotor wear is 0.5mm, total, estimated.
- Have had Ti plates added for over a couple years now however cannot conclude if these have made any positive difference...certainly has not affected braking. The idea was to help the rear pads retain heat thus function more effectively.
- Interestingly dust has remained same over the years based on visual inspection.

I will elaborate on each area further with observations and pix where possible.

William


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## pal (Aug 16, 2000)

Hi William - If you don't mind, please can you send me the spreadsheet you were using to calculate the front and rear brake torque values. I upgraded the rear brakes on my RS to HPA's kit that uses a 335mm rotor and 4 piston Baer calipers. I will be testing out on track for the first time this weekend and get feedback from there. But would also like to calculate theoretical brake torque data and front/rear bias to see how that compares to 1st hand testing. Tx.


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## 996cab (Aug 13, 2011)

pal said:


> Hi William - If you don't mind, please can you send me the spreadsheet you were using to calculate the front and rear brake torque values. I upgraded the rear brakes on my RS to HPA's kit that uses a 335mm rotor and 4 piston Baer calipers. I will be testing out on track for the first time this weekend and get feedback from there. But would also like to calculate theoretical brake torque data and front/rear bias to see how that compares to 1st hand testing. Tx.


 Consider it done...


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## hightechrdn (Dec 9, 2011)

996cab said:


> Consider it done...


Good day. Would you be willing to post/host the spreadsheet and post a link so that others could utilize it to assist with brake planning/changes? If that isn't possible, but you are willing/able to email me the spreadsheet, I would appreciate it.

(You already have my email address... I happened to send you an email less than hour ago, continuing Q&A on your MSS spring kits. To help narrow it down, my email just sent has 5 number questions in it.)

Thank you for your contributions to the TT/TTS/TT-RS community!


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