I have recently purchased an RS3 Sportback and just wanting to know if anyone could point me in the right direction for doing an RS7 rear brake upgrade and costs involved...
Rear RS7 brake upgrade
- Thread starter Nardo007
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Not quite sure why you want to make such a big upgrade to the rear brakes. The RS7 is a very much heavier car than the RS3.
Looking at the parts listings an RS3 standard rear brakes are 310 * 22 and the RS7 356*22 .
Thats a big difference in braking power and might cause some issue with the brake balance as the rears are more likely to lock up.
I would have thought something like this would be a better idea. Not sure if it will fit the RS3 but probably won't be far off.
https://store.034motorsport.com/335...e-kit-8j-audi-ttrs-to-c5-audi-rs6-rotors.html
Looking at the parts listings an RS3 standard rear brakes are 310 * 22 and the RS7 356*22 .
Thats a big difference in braking power and might cause some issue with the brake balance as the rears are more likely to lock up.
I would have thought something like this would be a better idea. Not sure if it will fit the RS3 but probably won't be far off.
https://store.034motorsport.com/335...e-kit-8j-audi-ttrs-to-c5-audi-rs6-rotors.html
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First question is - do you have the 8P or 8V?
I am in the middle of doing mine now - just waiting for some RS7 discs to pop up at the right price - If you have the 8V, you will need a caliper extender bracket as a start. I think BKS are the only people who have machined one. It is 493€ shipped. You could, if good with a milling machine, make these brackets, but this something only you will know.
https://www.bks-tuning.com/audi/a3-s3-rs3/a3-8v/performance.html
Next you will need two RS7 discs p/n 4G8-615-601. You might be fobbed off with 4G0-615-601 that are much cheaper, but they will not fit as they are RS6 pattern that has a lower offset. I guess in theory these could be spaced out, but not something I would want to take on!
Then, if you want, you will need two RS7 dust shields - p/n 4G0-615-611G and 4G0-615-612G. Then just bolt all these together! No need to undo the hydraulic line, but you will need Vagcom to wind the caliper pistons back.
Now, an alternative is to buy the whole kit from BKS at 1636€ delivered. This works out not too bad with the discs costing 571€ each which is down from the retail of 600-700€, but does not include the dust shields.
RS7 discs crop up now and again on ebay at good prices, you just need to keep an eye open as I am doing now. If you cannot wait though, I found a good price of £690 for the two from genuineautoparts.com/uk.
Desertstorm, the 'upgrade' is really a cosmetic one. For some inane reason only known to some strange designer perhaps, Audi used the 'wave' disc on the fronts and a piddly disc at the back. Aesthetically it looks stupid. Many German owners make this conversion one of their first jobs. I understand from those with the mod that it actually smooths out the braking making the front dip much less violent. Aoon here has the mod, but he has not posted for a while. He was considering ceramics front and back though. Maybe he has them by now - in which case there might be a conversion kit in the 'for sale' section soon..!
I am in the middle of doing mine now - just waiting for some RS7 discs to pop up at the right price - If you have the 8V, you will need a caliper extender bracket as a start. I think BKS are the only people who have machined one. It is 493€ shipped. You could, if good with a milling machine, make these brackets, but this something only you will know.
https://www.bks-tuning.com/audi/a3-s3-rs3/a3-8v/performance.html
Next you will need two RS7 discs p/n 4G8-615-601. You might be fobbed off with 4G0-615-601 that are much cheaper, but they will not fit as they are RS6 pattern that has a lower offset. I guess in theory these could be spaced out, but not something I would want to take on!
Then, if you want, you will need two RS7 dust shields - p/n 4G0-615-611G and 4G0-615-612G. Then just bolt all these together! No need to undo the hydraulic line, but you will need Vagcom to wind the caliper pistons back.
Now, an alternative is to buy the whole kit from BKS at 1636€ delivered. This works out not too bad with the discs costing 571€ each which is down from the retail of 600-700€, but does not include the dust shields.
RS7 discs crop up now and again on ebay at good prices, you just need to keep an eye open as I am doing now. If you cannot wait though, I found a good price of £690 for the two from genuineautoparts.com/uk.
Desertstorm, the 'upgrade' is really a cosmetic one. For some inane reason only known to some strange designer perhaps, Audi used the 'wave' disc on the fronts and a piddly disc at the back. Aesthetically it looks stupid. Many German owners make this conversion one of their first jobs. I understand from those with the mod that it actually smooths out the braking making the front dip much less violent. Aoon here has the mod, but he has not posted for a while. He was considering ceramics front and back though. Maybe he has them by now - in which case there might be a conversion kit in the 'for sale' section soon..!
Apparently the car brakes a lot better and is more stable from high speed the rs7 rear discs also no issues whatso ever. Give me half an hour to speak to one of the guys I know I think he has machined his own spacer for the calliper to avoid the hassle of getting it from abroad and the lead times prob a lot cheaper also.
They are doing a kit and posts from uk brand new rs7 rear discs and the proper machined calliper spacers around 800 all in I can give you the contact email if you'd like a set or anyone else
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Yes please - I have searched everywhere and can only find BKS. So, who is the contact..?
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Thanks Spaceman - all sorted! I owe you one as I was due to order everything from a more expensive source this week! And yes, he tried selling me the AP front upgrade. And an MTM box!
He has a set of light used discs he is skimming for me coming in at below the 800! Bargain! Just have to wait until he can juggle things around - he is off to Spa tomorrow racing some Porsche, so hopefully after that..!
He has a set of light used discs he is skimming for me coming in at below the 800! Bargain! Just have to wait until he can juggle things around - he is off to Spa tomorrow racing some Porsche, so hopefully after that..!
Hi,
Are these kits still available and is there anything else needed other than fitting?
Thanks
Tom email address if anyone wants to order is
tomwrigleyracing@outlook.com
He can be out the country racing but will pick emails up.
Cheers Greig
tomwrigleyracing@outlook.com
He can be out the country racing but will pick emails up.
Cheers Greig
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If anyone is seriously interested, Tom has (or had a few days ago, but he says he gets quite a few takers to might be gone..) one more set of lightly used RS7 discs that he might skim for you and the price is only 700 all included. New kits are now 1000 which is a lot cheaper than the kits from BKS.
100% Karl. Cast my mind back 22-years and I try to imagine the response from the VCA (Vehicle Certification Agency) to me presenting a car at MIRA for Motor Vehicle Type Approval to EEC Directive 91/422/EEC Road Vehicles (Construction and Use) - and on page #6 of the declaration "calculations" for 'Brakes' stating the rear brake discs are that big because they look better...
Back to revise the engineering and documentation I'm sure I'd be sent and ALL of that before evaluation on wet and dry road surfaces with differing vehicle loadings; does make one think on a little...
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Notwithstanding type approval documentation, fitting RS7 discs to the rears of an RS3 will not change the braking performance greatly, and what change there is will stabilise the violent dig in due to the extreme front brakes.
Larger discs on their own will not change anything at all. It is the grab area of the pads and position of the pads in relation to the centre point that produces the locking power:
Larger pad grab area = better grip = quicker locking.
The further away from the centre point of rotation = greater fulcrum = mechanical advantage.
In the case of this particular upgrade, the caliper/pad assembly is not being changed so that the grab area is not changed.
Yes, there is a spacer that extends the caliper mount position by 40mm, so there is a mechanical advantage of 40mm fulcrum, or about 17% of the pad area that is outside of the previous grab area gains this advantage. But then subtract the mechanical advantage the lost grab area would have had and, without carrying out the extended determining maths, the resultant gain in mechanical advantage I bet is no more than about 12%... This is best explained with pictures - so have a look at Aoon's thread on his total upgrade, where as it happens, the last two pictures show a before and after of the conversion.
Talk of brake of brake lock on such a conversion is a bit ott. If for no other reason that ABS these days is so sophisticated that brake lock is virtually unheard of. 22 years ago and yes, braking was much more of a calculable technology than it is now.
This upgrade is popular in Germany with the only complaint being that the owners resent spending money on the aesthetics that Audi neglected! All in all the upgrade is probably pretty useless in performance terms (other than reducing dig slightly) and is maybe placed one up from carbon fibre trim exchange on the mod list!
Larger discs on their own will not change anything at all. It is the grab area of the pads and position of the pads in relation to the centre point that produces the locking power:
Larger pad grab area = better grip = quicker locking.
The further away from the centre point of rotation = greater fulcrum = mechanical advantage.
In the case of this particular upgrade, the caliper/pad assembly is not being changed so that the grab area is not changed.
Yes, there is a spacer that extends the caliper mount position by 40mm, so there is a mechanical advantage of 40mm fulcrum, or about 17% of the pad area that is outside of the previous grab area gains this advantage. But then subtract the mechanical advantage the lost grab area would have had and, without carrying out the extended determining maths, the resultant gain in mechanical advantage I bet is no more than about 12%... This is best explained with pictures - so have a look at Aoon's thread on his total upgrade, where as it happens, the last two pictures show a before and after of the conversion.
Talk of brake of brake lock on such a conversion is a bit ott. If for no other reason that ABS these days is so sophisticated that brake lock is virtually unheard of. 22 years ago and yes, braking was much more of a calculable technology than it is now.
This upgrade is popular in Germany with the only complaint being that the owners resent spending money on the aesthetics that Audi neglected! All in all the upgrade is probably pretty useless in performance terms (other than reducing dig slightly) and is maybe placed one up from carbon fibre trim exchange on the mod list!
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Very in depth article here
http://stoptech.com/technical-suppo...ias-and-performance-why-brake-balance-matters
Also this is quite good
http://iracing.wikidot.com/components:brake-bias
By increasing rear brake bias you make the car potentially more unstable when braking, particularly in a situation such as trail braking into a corner when it's wet.With the unloading of the inside rear wheel it's more likely that the rear braking force will overcome the available grip .The wheels may not lock up because of the ABS but the handling is likely to be more twitchy.
If the car dives a lot less when braking harder then it would say to me that there is a big difference in the brake bias to the standard car.
The amount of traction a tyre generates is related to the load on it. With less weight on the front wheels the tyres will reach the point of locking earlier than they would normally.
http://stoptech.com/technical-suppo...ias-and-performance-why-brake-balance-matters
Also this is quite good
http://iracing.wikidot.com/components:brake-bias
By increasing rear brake bias you make the car potentially more unstable when braking, particularly in a situation such as trail braking into a corner when it's wet.With the unloading of the inside rear wheel it's more likely that the rear braking force will overcome the available grip .The wheels may not lock up because of the ABS but the handling is likely to be more twitchy.
If the car dives a lot less when braking harder then it would say to me that there is a big difference in the brake bias to the standard car.
The amount of traction a tyre generates is related to the load on it. With less weight on the front wheels the tyres will reach the point of locking earlier than they would normally.
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Yes - all very important. But both articles pertain to racing where it is a lot easier to set up the perfect brake bias. And racing cars do not have ABS. They have the luxury of known characteristics AND [often] an adjustable brake bias control.
A road car is subjected to so many changes and influences outside the designer's control - from the uncertain weight distribution of cargo through to fitment of cheap tyres and suspension equipment. For this the percentage change in a design is vast and has to be catered for.
We are discussing changing the performance of a rear brake of a very small percentage. The small gain in braking efficiency though is far outweighed by the two occasional meaty passengers on the back seat. I do not think the increase will any way near make the front wheels too light on braking - not with 140cm2 grabbing rotating steel of 18.5cms radius per wheel!
A road car is subjected to so many changes and influences outside the designer's control - from the uncertain weight distribution of cargo through to fitment of cheap tyres and suspension equipment. For this the percentage change in a design is vast and has to be catered for.
We are discussing changing the performance of a rear brake of a very small percentage. The small gain in braking efficiency though is far outweighed by the two occasional meaty passengers on the back seat. I do not think the increase will any way near make the front wheels too light on braking - not with 140cm2 grabbing rotating steel of 18.5cms radius per wheel!
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Tbh you are increasing the brake force at the rear a little with these discs. Look up the torque effect.
If you haven't driven an RS3 you won't have experienced the back of the car wanting to come to the front on harsh braking. These discs get rid of that completely. 100% recommend to anyone who's on the line.
ABS/ESP controls wheel lockup so that's a moot point
If you haven't driven an RS3 you won't have experienced the back of the car wanting to come to the front on harsh braking. These discs get rid of that completely. 100% recommend to anyone who's on the line.
ABS/ESP controls wheel lockup so that's a moot point
So my conversation kit has arrived from BKS. Does anyone know how hard or if there is a video of the install around?
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Do you really think he will talk to it, or is this just moderator prerogative to show where us serfs belong..?
Nardo - how mechanical are you? Assuming this stuff is not daunting, then:
1. Loosen wheel lugs.
2. Put brakes into service mode.
3. Put a note on the steering wheel not to touch brake pedal - or just lock the door!
4. Either lift car if you are fortunate to have a lift, or jack up and support rear of car.
5. Remove road wheels.
6. Using a stout screwdriver, prise back the brake pads so the disc moves freely.
7. Remove the bolts holding the calipers to hubs, remove calipers and hang out of way so the hose is not under strain.
8. Remove the little holding set screws on the disc bell and withdraw the disc and throw away.
9. Install the new caliper brackets - there will be a drg from BKS showing the exact way to do this.
10. Remove any scum from the drive flange and rear of new disc bell, and coat with a small film of copper slip.
11. Install new disc and locate with the small holding set screw.
12. make sure brake pads are in place correctly, slide on caliper and bolt to new brackets.
13. Re-attach road wheel, tighten lugs and let car back on ground.
14. Remove brakes from service mode.
15. Importantly, depress brake pedal a few times until you have a firm pedal before moving off.
You cannot really go wrong if you have the right tools. It might be worth asking BKS if they have a video as I bet they do somewhere, but the above should serve as a check list in absence of anything else.
It is not hard. The only difficult part might be getting a vagcom to put brakes into service mode depending on if you have any mates who might help out. If you do not then you may have to go to an independent Audi place and sweet talk them into doing it and let you borrow their two post lift! There are many on the internet who manually put the brakes into service mode - I do not agree with it, so will let you find the references but be it on your own head if you follow them!
I
Nardo - how mechanical are you? Assuming this stuff is not daunting, then:
1. Loosen wheel lugs.
2. Put brakes into service mode.
3. Put a note on the steering wheel not to touch brake pedal - or just lock the door!
4. Either lift car if you are fortunate to have a lift, or jack up and support rear of car.
5. Remove road wheels.
6. Using a stout screwdriver, prise back the brake pads so the disc moves freely.
7. Remove the bolts holding the calipers to hubs, remove calipers and hang out of way so the hose is not under strain.
8. Remove the little holding set screws on the disc bell and withdraw the disc and throw away.
9. Install the new caliper brackets - there will be a drg from BKS showing the exact way to do this.
10. Remove any scum from the drive flange and rear of new disc bell, and coat with a small film of copper slip.
11. Install new disc and locate with the small holding set screw.
12. make sure brake pads are in place correctly, slide on caliper and bolt to new brackets.
13. Re-attach road wheel, tighten lugs and let car back on ground.
14. Remove brakes from service mode.
15. Importantly, depress brake pedal a few times until you have a firm pedal before moving off.
You cannot really go wrong if you have the right tools. It might be worth asking BKS if they have a video as I bet they do somewhere, but the above should serve as a check list in absence of anything else.
It is not hard. The only difficult part might be getting a vagcom to put brakes into service mode depending on if you have any mates who might help out. If you do not then you may have to go to an independent Audi place and sweet talk them into doing it and let you borrow their two post lift! There are many on the internet who manually put the brakes into service mode - I do not agree with it, so will let you find the references but be it on your own head if you follow them!
I
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I forgot to add in step 8 - also remove and throw away the backing plate!
I am going to see if the RS7 back plate will fit, but I am a couple of weeks off my installation, so cannot say for sure. BKS say to leave it off.
I am going to see if the RS7 back plate will fit, but I am a couple of weeks off my installation, so cannot say for sure. BKS say to leave it off.
I am looking to just go without backing plate. A bit short of tools and time but I am now not concerned my local mechanic will be able to do it.
May I suggest a solution for the possible backing plate?
I have just about installed TTRS/RS3 brakes on my A3 8p. Coming from previous S3 8p front brakes.
The S3 disc were 345mm and the new RS disc is 370mm. Now my S3 backing plates where to small.
I did not fancy running with out the backing plates for two reasons.
1. Great heat is melting the sensors and other rubber/plastic parts around.
2. All the degrees and salt during winter time.
My solution to the problem was to swap plates between left and right. This was an easy and great way. Trust me on that.
Not sure if this is possible on the rear. But it's worth the try.
Keep us posted.
I have just about installed TTRS/RS3 brakes on my A3 8p. Coming from previous S3 8p front brakes.
The S3 disc were 345mm and the new RS disc is 370mm. Now my S3 backing plates where to small.
I did not fancy running with out the backing plates for two reasons.
1. Great heat is melting the sensors and other rubber/plastic parts around.
2. All the degrees and salt during winter time.
My solution to the problem was to swap plates between left and right. This was an easy and great way. Trust me on that.
Not sure if this is possible on the rear. But it's worth the try.
Keep us posted.
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That is a great idea! Full marks!
I will have a look and see if possible next week.
I agree with you on the back plate despite everyone saying they are not totally necessary. But the main reason I want to try and get RS7 plates is my warranty. I have a four year warranty which is silly to ignore. The only modification I am doing is the rear discs, other than oem roof rails, which I want to make it appear that it was 'done at the factory' for the end of production run or such like. I am sure if this was ever done, then Audi would have fitted a dust shield. As the car originated in the Czech Republic and I am in a particularly remote part of S France where there the RS3 is far and few between, ~I am hoping that the dealer will just see the wavy disc on all corners, and as the wave is a signature mark of Audi RS (apparantly, a design adopted after Audi bought Ducatti) my dealer will not look further. In not having a back plate just might make them ask a question or two...
I will have a look and see if possible next week.
I agree with you on the back plate despite everyone saying they are not totally necessary. But the main reason I want to try and get RS7 plates is my warranty. I have a four year warranty which is silly to ignore. The only modification I am doing is the rear discs, other than oem roof rails, which I want to make it appear that it was 'done at the factory' for the end of production run or such like. I am sure if this was ever done, then Audi would have fitted a dust shield. As the car originated in the Czech Republic and I am in a particularly remote part of S France where there the RS3 is far and few between, ~I am hoping that the dealer will just see the wavy disc on all corners, and as the wave is a signature mark of Audi RS (apparantly, a design adopted after Audi bought Ducatti) my dealer will not look further. In not having a back plate just might make them ask a question or two...
But for shure they aren`t going to do anything on warranty if you got rear brake problems or probably any brake problems at all because of the upgrade which is not oem on this car, Audi or not. If they are your buddies it maybe will work and it`s ok with them otherwise not. It`s the same for me with changing to Tarox and the warranty will be gone on brakes but although I have decided to do it because of crappy quality, two left side discs and poor airflow to cool them. The airflow is not improved of course but quality is better and probably more heat resistant.
Got the local mechanic to do it to save time, he said the BKS kit fitted up with all parts perfect. He gave me the original parts, I just relised that I didn't get my shields. I then reached behind the new rotors and the original shields are still there fitted. Can't be a bad think I guess. Brakes work great, there seems to be a bit more bit, major improvement in the looks department!
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Interesting. The lip must not curve over the top of the disc then. They will keep most of the stuff out, so leave them as is, good idea.
I found a pair of RS7 dust shields on ebay for 40 odd euros so have cut both at a suitable point and splicing the RS7 outer part onto the centres of the A3 shields.
