IanH's 955hp V10 Audi RS6 - Another Car Diary!
Discussion
I had Project Mu on my R34 and rate them highly but they don't do anything for this new Radi-Cal caliper yet. I can't really have full track pads fitted as this is my daily driver (hence the DS2500's) but I'm looking at getting a spare set of "track only" pads and discs so I'm looking at Ferodo DS3000, Carbotech XP10, Hawk Ceramic and Cobalt Friction XR1/2 for those (the only companies currently making pads for these calipers) or asking AP themselves to make me a set with a different compound (APF 401/402).
My Rear Diff - IT GO BOOOOOOMMMMM!!!!!!
Well it's more of whine to be more accurate (sorry the click-bait
)
With a 100k+ mile car pushing 900hp+ for the last 8000 miles it's no wonder there was going to be a weak spot found eventually. I was expecting it to be a driveshaft TBH but the rear diff was also a worry (front diff/transfer box all in uprated GB) as well as potentially the wheel bearings (replaced during 900 conversion).
I dropped it off at the garage last night and they've just confirmed the bearings had failed and were making some quite impressive noise on the lift
So heres my symptoms and a quick vid of the noise for those who are interested -
Whine only present when pressing the throttle, even just 1-2%. No whine when off throttle.
Noise is road speed dependant not gear/rev. I tried 2nd-6th at 40mph so 5500rpm to 1500rpm and the whine stays the same.
Noise starts from 20mph to 100+ and the whine starts as a low freq low volume noise. At 40 and 60mph the volume peaks (resonance) and then rises to extremely high freq low volume by 100mph+.
Cornering & bumps have no effect on the noise nor does braking (if you keep the throttle pressed too).
Passenger's in the back seat at the time said there was "buzzing" by their feet under load.
The rest of the car drives, stops & handles exactly as before but the MPG was down slightly (6 less MPG shown when doing 60mph on a motorway) due to the increased drag in the drivetrain.
In the video I'm just tapping the accelerator a tiny amount every 1-2 seconds so the noise appears/disappears making it easier to hear the difference.
Video - https://www.youtube.com/watch?v=74gSiI0vT80
So my initial plan was to check with Audi for costs/time for a new one. After the call I had a cry and a sit down (which was very difficult considering the vigorous bumming Audi^^^ gave me) and then got around to finding a decent gearbox place in Kent to get it rebuilt instead for under half the price of a new one. It should be all back running next week with my new brakes fitted, new diff and a considerably lighter wallet!
PS Warranties are very important! If your current one runs out and can't be extended (car now over 100k miles) then get another one pronto! Doh!
^^^Audi wanted £4300 with an unspecified waiting time as they had none anywhere, not even in Germany.
Well it's more of whine to be more accurate (sorry the click-bait
)With a 100k+ mile car pushing 900hp+ for the last 8000 miles it's no wonder there was going to be a weak spot found eventually. I was expecting it to be a driveshaft TBH but the rear diff was also a worry (front diff/transfer box all in uprated GB) as well as potentially the wheel bearings (replaced during 900 conversion).
I dropped it off at the garage last night and they've just confirmed the bearings had failed and were making some quite impressive noise on the lift
So heres my symptoms and a quick vid of the noise for those who are interested -
Whine only present when pressing the throttle, even just 1-2%. No whine when off throttle.
Noise is road speed dependant not gear/rev. I tried 2nd-6th at 40mph so 5500rpm to 1500rpm and the whine stays the same.
Noise starts from 20mph to 100+ and the whine starts as a low freq low volume noise. At 40 and 60mph the volume peaks (resonance) and then rises to extremely high freq low volume by 100mph+.
Cornering & bumps have no effect on the noise nor does braking (if you keep the throttle pressed too).
Passenger's in the back seat at the time said there was "buzzing" by their feet under load.
The rest of the car drives, stops & handles exactly as before but the MPG was down slightly (6 less MPG shown when doing 60mph on a motorway) due to the increased drag in the drivetrain.
In the video I'm just tapping the accelerator a tiny amount every 1-2 seconds so the noise appears/disappears making it easier to hear the difference.
Video - https://www.youtube.com/watch?v=74gSiI0vT80
So my initial plan was to check with Audi for costs/time for a new one. After the call I had a cry and a sit down (which was very difficult considering the vigorous bumming Audi^^^ gave me) and then got around to finding a decent gearbox place in Kent to get it rebuilt instead for under half the price of a new one. It should be all back running next week with my new brakes fitted, new diff and a considerably lighter wallet!
PS Warranties are very important! If your current one runs out and can't be extended (car now over 100k miles) then get another one pronto! Doh!
^^^Audi wanted £4300 with an unspecified waiting time as they had none anywhere, not even in Germany.
got my car back with a new rear diff and the AP Racing 410mm Radi-Cal setup with custom braided brake lines.Brakes re-bled (got some air out) and pads bedded releasing a vast quantity of smoke and the brakes are stunning!!!
I'm hitting the tyres grip limit at *well* above motorway speeds which is much better than before where it braked strongly down from high speed to 70mph-ish before starting to chirp the tyres.
Now I just need to sort the knocking from the OSF DRC strut which is leaking at a union in the arch. I've got a 10k servicing, GB service and DRC re-pressurisation at Unit20 in a few weeks so hopefully everything will be well afterwards!!!
I'm hitting the tyres grip limit at *well* above motorway speeds which is much better than before where it braked strongly down from high speed to 70mph-ish before starting to chirp the tyres.
Now I just need to sort the knocking from the OSF DRC strut which is leaking at a union in the arch. I've got a 10k servicing, GB service and DRC re-pressurisation at Unit20 in a few weeks so hopefully everything will be well afterwards!!!
So then, TLC time!!!
I've been buying a few bits just to sort out some of the cosmetic issues I have from it being a 100k mile daily driver -
The cleaning rags filled a 35L bin to make them look that good, they were filthy! It was mainly the calipers with 100k miles of baked on grime!
I've been buying a few bits just to sort out some of the cosmetic issues I have from it being a 100k mile daily driver -
- Fitted a new front splitter to replace the badly battered and bruised one which the previous owner had glued 2 Laser Jammers too. During their none too subtle removal by MRC (think chisels/screwdrivers were used) the plastic splitter was scratched to pieces and cosmetically wrecked. Simple job to replace, 5x Torx bits and some trim poppers, took about 15mins after I'd got the car jacked up after Tea.
- Changed the license plate holder screws (rusted) & broken plastic protectors for a new set.
- Tomorrow I'll be fitting a new engine undertray, just need 15 1/4 turn fasteners from Audi - no point fitting old rusty ones.
- Friday is the 10k service at Unit20 and DRC re-pressure and I'll also get some pics of the new brake setup too.
- Found some rust in the NSR arch which needs sorting before winter starts.
The cleaning rags filled a 35L bin to make them look that good, they were filthy! It was mainly the calipers with 100k miles of baked on grime!
Busy day up at Unit20 in the Wirral -
10k Servicing
Gearbox Service
Rear Diff Oil re-fill
New engine undertray fitted
Front suspension arm noise located (to be dealt with next month)
DRC suspension leak found (to be dealt with next month)
Other than the servicing bits, we found that the creaking/clunking noise was from the suspension arms and that the DRC leak, which was a slight weep a month ago, has now stopped (yay) but the flexible pipes are very badly corroded and need replacing before it can be re-pressurised (boo) so, with 100k miles on them, it'd be rude not to replace the struts at the same time for a complete suspension refresh (yay-me/boo-wallet).
10k Servicing
Gearbox Service
Rear Diff Oil re-fill
New engine undertray fitted
Front suspension arm noise located (to be dealt with next month)
DRC suspension leak found (to be dealt with next month)
Other than the servicing bits, we found that the creaking/clunking noise was from the suspension arms and that the DRC leak, which was a slight weep a month ago, has now stopped (yay) but the flexible pipes are very badly corroded and need replacing before it can be re-pressurised (boo) so, with 100k miles on them, it'd be rude not to replace the struts at the same time for a complete suspension refresh (yay-me/boo-wallet).
Thanks for the comments folks!
chuntington101 said:
On the intercooling front, have you considered spraying the intercoolers with water?
It's a good idea if you have temps issues when driving but, as my only issue is at stand still, the water spray wouldn't be as effective compared to driving use. Once you're moving and have airflow through the IC fins, the heat soak drops in around 30 seconds at 40mph (looking at my logged intake temps) so, as it's a very "situational" issue (no air flow for around 3-5 mins then straight onto full throttle), I'm not sure I can justify the extra costs involved with an I/C spraybar.The engines the strongest part of the car, the extra power is now finding all the cars weakspots now which seems to be mainly drive line but I'm very surprised that, after 8k miles of daily driving with full throttle at least twice a day, nothing more has "gone wrong" other than a rear diff so far, I was expecting it to be the driveshafts personally.
The other issues like DRC suspension/arms are age related rather than power.
The other issues like DRC suspension/arms are age related rather than power.
Edited by IanH755 on Monday 12th September 21:24
Dr G - Yeap, as well as purging the nitrous lines of any gas it's also extremely cold (-88'c) which cools down the IC's much more effectively than static water can. You can also see them using a CO2 extinguisher as well which is a cheaper method.
Santa Pod etc also say that IC water sprays aren't allowed as it leaves the start line wet.
One from the Pistonheads Sunday Service at Brands Hatch. Some really cool cars there inc the Aston Martin DB7 next to me, a Renault 5GT Turbo 2, Jaguar XJ220 and the new Aerial Nomad to name a few -
Santa Pod etc also say that IC water sprays aren't allowed as it leaves the start line wet.
One from the Pistonheads Sunday Service at Brands Hatch. Some really cool cars there inc the Aston Martin DB7 next to me, a Renault 5GT Turbo 2, Jaguar XJ220 and the new Aerial Nomad to name a few -
Edited by IanH755 on Tuesday 13th September 09:10
Hi Dominick, I'll break down the answers separately as they're quite long -
1. AP Callipers - The pedal now has a very "2-stage" feel with a softer 1st stage being adequate for day to day and a much harder 2nd stage when you really want to slow down quickly. The 1st stage feels like the OEM calliper did but the 2nd stage is a much firmer pedal feel compared to the OEM feel. It's caught me out a few times as my muscle memory is still adjusting so I found myself over-braking quite a bit for a few weeks. For clarity I also swapped fluid from ATE Superblue to Castrol SRF and swapped from OEM rubber hoses to HEL braided at the same time so how much extra pedal "firmness" is purely calliper I can't say. As to stopping "power" I find the tyres are reaching their grip limits much more quickly than with my OEM calliper/AP 390mm disc/Ferodo DS2500 setup. However the initial bedding in was much worse due to the new AP DS25 pads gassing off massively and giving no braking force after 5-6 80mph-10mph stops where it would brake to 40mph and then there was nothing, just a solid pedal and no brakes. However once through that, by 8-9 stops, the gassing off was complete and the brakes were amazing!
2. OEM Discs/pads/callipers - OEM discs are garbage for fast road use unless the backing plates are swapped for the Phaeton ducted versions when they become "adequate" at best. They are a massive heat sink with no OEM cooling so they overheat rapidly, hence adding the phaeton duct. If you like to drive quickly then I urge you in the strongest possible way to fit the 390mm AP discs with better fluid (ATE Superblue/Type200, Motul RBF600, AP Radi-cal R4, Castrol SRF etc). They are nearly 4kg lighter per disc, made of much better material and are properly cooled by their internal fins. The AP discs are £800 initially and then £600 when needing replacing as the £100 hat per side is only bought once. The OEM Pads are fine but can definitely be improved with either Ferodo DS2500's for £200 or Pagid RS29's if you can stomach the £500 cost! The OEM callipers are fantastic and are the strongest part of the OEM setup, they can take much more abuse than I managed to give them but they're limited to 405mm max disc size.
3. Lowered - Nope, KW do a really nice set of adjustable springs but the lack of adjustable upper arms means the increased camber can't be corrected leading to worn tyres.
4. H&R ARB's - Definitely made the car feel stiffer. If you imagine the 3 DRC settings as numbers 1-2-3 (Comfort-Dynamic-Sport) then the cars now feels like 1.5-2.5-3.5. I drive mine everyday in Dynamic mode and it now feels like a halfway point between Dynamic and Sport which I'm happy with. They have "almost" dialled out the post apex nose push but I've found a better driving technique to sort out my under-steer instead and the new forward brake bias is allowing the lighter rear to swing out more easily giving a sharper turn in which feels fairly flat considering the 2+ ton weight shift. I really need to get some track time now I'm happy with the brakes just to give them a good session, Tom already has 2 under his belt now so I'm playing catch-up
Hope that helps.................................Ian
1. AP Callipers - The pedal now has a very "2-stage" feel with a softer 1st stage being adequate for day to day and a much harder 2nd stage when you really want to slow down quickly. The 1st stage feels like the OEM calliper did but the 2nd stage is a much firmer pedal feel compared to the OEM feel. It's caught me out a few times as my muscle memory is still adjusting so I found myself over-braking quite a bit for a few weeks. For clarity I also swapped fluid from ATE Superblue to Castrol SRF and swapped from OEM rubber hoses to HEL braided at the same time so how much extra pedal "firmness" is purely calliper I can't say. As to stopping "power" I find the tyres are reaching their grip limits much more quickly than with my OEM calliper/AP 390mm disc/Ferodo DS2500 setup. However the initial bedding in was much worse due to the new AP DS25 pads gassing off massively and giving no braking force after 5-6 80mph-10mph stops where it would brake to 40mph and then there was nothing, just a solid pedal and no brakes. However once through that, by 8-9 stops, the gassing off was complete and the brakes were amazing!
2. OEM Discs/pads/callipers - OEM discs are garbage for fast road use unless the backing plates are swapped for the Phaeton ducted versions when they become "adequate" at best. They are a massive heat sink with no OEM cooling so they overheat rapidly, hence adding the phaeton duct. If you like to drive quickly then I urge you in the strongest possible way to fit the 390mm AP discs with better fluid (ATE Superblue/Type200, Motul RBF600, AP Radi-cal R4, Castrol SRF etc). They are nearly 4kg lighter per disc, made of much better material and are properly cooled by their internal fins. The AP discs are £800 initially and then £600 when needing replacing as the £100 hat per side is only bought once. The OEM Pads are fine but can definitely be improved with either Ferodo DS2500's for £200 or Pagid RS29's if you can stomach the £500 cost! The OEM callipers are fantastic and are the strongest part of the OEM setup, they can take much more abuse than I managed to give them but they're limited to 405mm max disc size.
3. Lowered - Nope, KW do a really nice set of adjustable springs but the lack of adjustable upper arms means the increased camber can't be corrected leading to worn tyres.
4. H&R ARB's - Definitely made the car feel stiffer. If you imagine the 3 DRC settings as numbers 1-2-3 (Comfort-Dynamic-Sport) then the cars now feels like 1.5-2.5-3.5. I drive mine everyday in Dynamic mode and it now feels like a halfway point between Dynamic and Sport which I'm happy with. They have "almost" dialled out the post apex nose push but I've found a better driving technique to sort out my under-steer instead and the new forward brake bias is allowing the lighter rear to swing out more easily giving a sharper turn in which feels fairly flat considering the 2+ ton weight shift. I really need to get some track time now I'm happy with the brakes just to give them a good session, Tom already has 2 under his belt now so I'm playing catch-up
Hope that helps.................................Ian
Converted £120 worth of fossils to fun hooning around the roads of Kent, Surrey and Hampshire for the RS246 club meet, Hindhead Tunnel Run and a quick visit to the Goodwood Motor Circuit.
Slightly over 5000hp combined at the meet, with the most obnoxious sounding exhaust I've ever heard on a family car in front of me during the tunnel run!
Easily the best run I've had out in my car for what seems like 2-3 months, great day!
Slightly over 5000hp combined at the meet, with the most obnoxious sounding exhaust I've ever heard on a family car in front of me during the tunnel run!
Easily the best run I've had out in my car for what seems like 2-3 months, great day!
Bugger!
As a "Happy Christmas" present my car has decided to do something catastrophic, involving the No1 Cylinder and a whole bunch of burnt oil! I'm in the process of stripping the intakes down and pulling the No1 plug out when my s
tty luck continued.
Not only does my spark plug tool not fit, not only has the locking part of the coil-pack plug dropped somewhere into the engine bay (supposed to stay attached) but I've also somehow managed to drop a little spring from my pliers down the intake pipe past my blue-roll "blocker" (1 squillion to one shot!) and it's now sitting nicely infront of the turbo blades (hence the boroscope shot of the turbo), which should be fun getting out if it's not magnetic!
Once I get to Halfords for a new spark plug tool on boxing day I'll eventually take the plug out and boroscope the cylinder to see whats happening and see why the plug isn't firing properly. I did notice the Crankcase Vent pipe line from the oil separator to the turbo's is dripping with fresh oil when it should only have vapour residue, not good!
Anyway Happy Christmas Everyone
As a "Happy Christmas" present my car has decided to do something catastrophic, involving the No1 Cylinder and a whole bunch of burnt oil! I'm in the process of stripping the intakes down and pulling the No1 plug out when my s
tty luck continued. Not only does my spark plug tool not fit, not only has the locking part of the coil-pack plug dropped somewhere into the engine bay (supposed to stay attached) but I've also somehow managed to drop a little spring from my pliers down the intake pipe past my blue-roll "blocker" (1 squillion to one shot!) and it's now sitting nicely infront of the turbo blades (hence the boroscope shot of the turbo), which should be fun getting out if it's not magnetic!
Once I get to Halfords for a new spark plug tool on boxing day I'll eventually take the plug out and boroscope the cylinder to see whats happening and see why the plug isn't firing properly. I did notice the Crankcase Vent pipe line from the oil separator to the turbo's is dripping with fresh oil when it should only have vapour residue, not good!
Anyway Happy Christmas Everyone
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