RS5 carbon clean DIY

A5/S5/RS5
#21

What supercharger are you running? PES? I see your car is Sepang and I remember a PES Sepang being for sale a year ago. I don’t think they ever got that car running correctly. So curious if that is indeed your car and if you’ve made some changes to the tuning for the ECU and TCU. Right now they’re the only game in town although Addict Motorsports is supposed to have their own roots-type for the RS5 this month.

At 40K, IMO, the RS5 needs to be carbon cleaned. Honestly every 20K would be about right. I’m going to do mine every two years from here on out (that’s 20K miles for me). No way in hell that’ll be your last carbon clean unless you sell the car or blow the motor, LOL. There’s nothing that can be done short of designing a set of secondary port injectors to run with the DI system. Not meth, not a can of seafoam (or similar), nothing is going to prevent it coming back except a stead stream of gas hitting the valves.

Yep, Costco here in Texas (and I’m assuming elsewhere) now serves up top tier gas. I’ve never had a bad tank of gas per se with the RS5 although they did screw up and put 87 in the 93 tank about 1.5 years ago. I actually received a refund for the difference which is how I found out.

Speaking of which, I filled up today and premium 93 octane was $2.19 a gallon! That’s not a typo. I was paying .60 cents more a gallon three weeks ago. Need to order a few 55 gallon drums. Isn’t going to last long, OPEC’s meeting next week.

#22

I did find that walnut shells are possibly quicker but when you take into consideration the blasting time to set up take down filling etc… its for me… to close to call. What I didn’t like what that I noticed blast material in the cylinders. As some of it gets past the valves in some cases as you would have to go cylinder by cylinder to assure full close of the valves.

#23

I don’t know that you would NEVER need a clean. As there is going to be build up there isn’t anything that I can think of that they would do to prevent that. BUT when a supercharger your going too see less build up than a NA car and even tho APE had a good amount of build up it wasn’t quite RS4 levels of build up. Its almost like Audi got a little better with the PCV and oil separator systems.

I keep hearing mixed results on costco gas. Its very affordable… now afordable is important safe is higher on the list for me.

#24

That’s exactly what I did. I had a 3/8" breaker bar on the crank and would rotate the assembly (really easy btw…like no friction) and make sure the valves were closed. Only then would I blast away. I also picked out and then air blasted out anything that was left, using the adapter and the shop vac to suck everything up an out of there with no mess.

I’d be able to cut the time needed by a third with a larger compressor and a water vapor filter inline with the pressure hose. Those two things cost me a lot of time. If you’re between 130 and 200psi with walnut shells, it cleans amazingly quick. I had a very small half gallon but super quiet compressor. I really should have purchased something with more power. I’ve seen other videos where they have the water vapor filter and a more powerful compressor and it was clean as a whistle in minutes. Live and learn!

#25

I think Big is using the APR unit tuned by JHM. JHM tuned the RS4 and the S5 for APR. APR just made a few changes.

As for units for the RS5. PES and Addict are pretty much the same bumbling idiots making the same mistakes both having a terrible reputation for being the slowest with the most issues and list of blown or just poor running motors. They only difference is Addict spends more time attacking people on line and giving there customers discounts to do the same in hopes of scaring people out of buying the better performing products of say JHM and APR…

Personally I would wait for JHM’s Vortech unit that I thin is supposed to be out early to mid next year. All company issues aside. Think about this. On this site its documented that PES blew a RS5 motor and APR dumped the RS4 RS5 blowers from there line up… why… Well roots style blowers are not typically used on high RPM motors with great success.Between heat and lack of flow they just don’t perform.

One Addict customer who later sold his kit for the RS4 after he seemed quite dissipointed posted logs on this site that showed the best unit they had for the RS4 was actually loosing CFM and falling off up top. The roots style kits are too hot and just don’t flow enough

#26

Good for you. Thats how I did it but still found small meida. For me I like the chemical submersion you can get. I found too many times I just couln’t target the back angles of the valves as much as I would like and Im just anal. Your right tho bigger compressor allows for much better push… I guess you can say… Overall I really enjoy your in depth work. Good for you thanks for sharing.

#27

I don’t know that you would NEVER need a clean. As there is going to be build up there isn’t anything that I can think of that they would do to prevent that. BUT when a supercharger your going too see less build up than a NA car and even tho APE had a good amount of build up it wasn’t quite RS4 levels of build up. Its almost like Audi got a little better with the PCV and oil separator systems.

I keep hearing mixed results on costco gas. Its very affordable… now afordable is important safe is higher on the list for me.
[/quote]
With the RS5, they did change the PCV and air oil separator system. They also apparently run the car a bit hotter which lessens the volatiles buildup in the oil. I’m sure they changed the valve overlap a bit too and oils have gotten better too (like Motul Specific).

My father worked in the petrol (gas) industry as an engineer as well as sales. All the big guys basically “order” their gas with their specified packages (detergents, performance additives, lubes, etc…) but they’re all basically refined in the same places. I think we’re down to six refineries with one more scheduled to come online. I don’t keep track much these days. Anyway as long as it’s labeled top tier, you’re getting the best stuff. It’s actually better to purchase from a really busy gas station like Costco as the gas is fresh as they say. But it meets the minimum octane rating and qualifies as top tier due to the additives package.

Speaking of which, I really need to experiment with some toluene or xylene. That stuff’s around 117 octane and makes a nice octane booster. I used it in my tuned to the edge of death big turbo rotary. The tune is “adaptive” so I should see some benefit or at least it running at optimal consistently. Toxic as shit though.

#28

Race gas a really good read. From a really smart guy.

http://audirevolution.net/forum/index.php?topic=2601.0

This is my bible.

#29

[/quote]
Good for you. Thats how I did it but still found small meida. For me I like the chemical submersion you can get. I found too many times I just couln’t target the back angles of the valves as much as I would like and Im just anal. Your right tho bigger compressor allows for much better push… I guess you can say… Overall I really enjoy your in depth work. Good for you thanks for sharing.
[/quote]
There was quite a bit of carbon material around the valve seat or where the port narrowed down around the outside of the valve. That area plus the back side of the valve guide is where it liked to hide. I used picks to get at that. I’d make a great dentist, LOL. But yeah a liquid solvent would probably get into the crevices a bit deeper maybe. I did think about spraying everything down with the CRC carbon cleaner I had and leaving it. Probably should have done that. I did soak it in carb cleaner and then wiped, sucked and blew all that out.

#30

As Justin mentioned it’s the APR charger on a B8 S5, the car in my SIG is what I wish I could have here. B8 RS5 manual. We only got the B8.5 face smashed ;D auto :’(

Sounds like I better learn how to carbon clean, but seems so much easier to pay a shop 1k to do it. I can see my cats jumping onto the table scattering all bolts everywhere after I have the manifold off…

I think I may try Costco again, and then i’ll report back. That’s what I hear that all gas is pretty much the same only each brand adds their special mix of detergents on site.

We’re at ~$3 a gallon for premium 91 octane. $2.19 is amazing!

Yup, APR with the JHM tune! running beautifully still!

Didnt flyingtomatoes blow his RS4 engine on the APR TVS1900? Seems like the S5, RS4 were good for up to 560-600 max hp and then after that risk for BOOM was high. Ya the roots seem to work well with the S’s RPM range gaining most power 3500-6200 RPM, after that it’s noticeable that the curve drops off

#31

Ah ok gotcha…I looked at the small thumbnail and thought you had an RS5.

It is physically easier to hand over a grand (or more) as paper money or a credit card doesn’t weigh that much. But I’m mechanically curious and honestly I was drooling over the thought of taking everything apart. So much interesting engineering going on.

If they quote you a price for the carbon clean, make sure it includes the injector repair kit. I don’t know why Audi didn’t use a simple girdle or something to screw down the injectors so they don’t come up with the LIM.

I’m not sure what to think about the 4.2L’s potential. I know the RS5’s CFSA 4.2L is a newer design has forged everything where the S5 4.2L does not. Unsure about the RS4 but it seems crazy they’re maxed out at 600 flywheel hp. There are more than a few Nissan VQ naturally aspirated (originally) 3.7L V6 engines making 700 wheel hp on the original engine. I honestly think it’s the tuning. There are a number of good shops tuning the Nissan motors and software is widely available. I don’t see that with Audi and it seems tuners are few and far between and no one has ever heard of them. No one does remote logging/tuning either. It’s all off the shelf one size fits all.

#32

Nice good to hear. As menttioned we know JHM tuned APRs supercharged RS4 and S5 for them so that makes sense that the JHM tune would still be doing well.

APR did have some issues with the 1900 and blown motors. Flyingtomato had issues but to APRs credit they worked to help him get a new motor. Then a ton of power was pulled out and after several more issues between the RS4 APR stepped out of the supercharger race. They tried on the RS5 but reportedly had issues there as well. Not so much tuning issues as it was just the motors didn’t like the extra power.

And your so so right. The roots blowers just fall off up top. We can see it in the logs the dynos and seat of the pants.

#33

I’m not sure APR had full control of the RS5’s computer and all it’s parameters honestly. If they did, their tune for the n/a car would have produced far more hp than it does. I still think it’s a tuning issue, maybe sizing the intercoolers correctly…I do know if there’s one parameter not inline with what the ECU is expecting to see, it causes problems. The RS5 does not do well with heat soak at all. I know when I did a few dyno runs with the JHM tune, it was, admittedly, very consistent on a dynojet. Not so much on a Mustang Dyno but I blame the operator for that. Plus the ECU is tied into the TCU but apparently, the DL501 is actually capable of handling 1,000Nm of torque and 10,000rpm.

ECU’s are complicated beasts. Everything is encrypted and you have to know where to look. Case in point, there are two main tuning suites for the Nissan VQ. One, ECUTek, had full control over the variable valve lift and duration maps. The other, UpRev, did not (along with a few other disadvantages) and as such, the ECUTek cars would make more hp and be far safer under high levels of boost. Both would manage basic timing, fueling, cold start tables, etc…the normal stuff. But the ability to control the lift and duration was a game changer when it came to high boost and cylinder pressure management.

I don’t see any inherent design flaw in the RS5’s engine that would keep it from making big numbers with proper tuning. It’s biggest disadvantage would be the compression ratio but it’s no more than the VQ motor. I mean hell, UkuRiSH on the Audizine forum is making 545 wheel with the 3.0L in his S5. That’s 725hp on a V8 with two more cylinders at 90hp/cylinder. It’s all in the tuning AND a proper fuel system to support the hp level.

The RS5 is essentially the new V10 motor with two cylinders lopped off. No one says the V10 can’t handle boost. It seems to take to a roots blower like a fish to water. But it’s a properly-engineered kit with a properly-sized blower. No reason we can’t have the same on the RS5.

#34

APE should we cut the off topic part of this thread and make it into a new one. I feel like I’m taking your DIY thread and going way off topic.

I like your approach to working on the car. I always feel the same way.

As for the 4.2 potential.

With the RS5 tuned going 11s from JHM I would say there is a good platform with no supercharger. Fun fast high revving V8. Thats a good starting point. I just got a JHM supercharger kit for my S4 and I’m looking to go as fast with my JHM supercharger that your going all motor.

The RS4s can make 600whp. I think JHM had a RS4 guy who dynoed at 034 and made 570whp or more. But that was on a built motor.

To the point of tuning. Part yes and part no. The real issue is the Audi motors themselves.

Your example is a 340hp 7000rpm motor. The RS4 is a 421hp 8200rpm motor… Thats night and day difference in motors and how they are going to run and be built.

The RS4 and RS5 are all beefy motors and your not going to damage a piston or a rod with power. many times its been said you can probably make 700whp and not take out a rod or piston.
The roots style kits usually run so hot that piston damage was an issue but the real issue is the ring sets. at 8500rpm you need to have a very close ring set. Too much power too much heat your going to have ring issues. No tuning is going to change that as the ring set expands to keep compression at the RPMs climb and heat increases. So that is not something you can tune or work around. You have a limit as to how far you can push.

Tuning wise the Vag cars have usually the newest in tuning systems. Domestics are usually 10 years behind toyota is always several years back but not as far back as domestics. JHM has a experienced tuner not just in the Vag cars as he helps other companies but hes an actual calibrator ourside of JHM. So that plays a roll.

Why no remote tuning. Again with the Audi Vag systems you have something like 50 ignition tables and 10 fueling tables and the same goes for almost all of the sub systems. Its not old and not adaptive. So you really shouldn’t need to ever do remote tuning to be honest. You should be able to tune for almost every situation. I know JHM will look at your logs and make adjustments if there needs to be any so with that picking JHM is going to be a smart move. They are big enough to compete and small enough to care.

Hope that adds some info to help make more sense of things.

#35

Im a fan of APR but I would probably agree that they didn’t have a good grip on the RS5. JHM IMHO has shown to have much better understanding and APR knows that as they have had JHM help them tune in the past.

The RS5 would make sense that it would kill power if heat became an issue because too much heat causes bad issues. Overall everyone wants a fast car but most want a fast running car all the time. So protection is going to be top of the list. the DL501 can handle lots of power but isn’t tuned out of the box to actually handle all that power. You need to unlock it. good to know JHM is currently working on that.

Your ECU example makes good sense. But it seems companys like JHM and APR know what they are doing and companies like addict and PES don’t. I would never put any tune from either on my car from them. and not just because I feel they are not companies I would spend money with its that they have shwon they don’t know what they are doing.

On the RS5 the flaw like I said is the rings. Its not the other components. You have to be careful using the 3.0T Vs the 4.2 as the 3.0T is already set up with forced induction and it revs 1500 less RPM. going from 7000 to just 8000 is a MONSTER in difference.

#36

Don’t worry about the thread hijack. Once I have everything complete on the other site, I’ll “port” it over here. I can’t go back and edit posts on this forum so I don’t want to post anything til I’m done. So I’ll start a new thread and put it all there. I just want to have good technical discussions with other knowledgable enthusiasts! Sometimes I think it’s just you and me hanging out in the RS5 forum, LOL.

I can see high IAT’s causing issues as it happens with the car stock and pulling timing when hot. The VQ motors run 7500rpm and 8500rpm with the Nismo oil pump. Their ring package is packed tight and high up as well. If the ring specs are more in favor of less friction (and I suspect they are after turning the engine by hand) then that makes sense. If you’re getting blow by or pressure damaging ring lands, well there you go.

But all of this is moot if the piston design doesn’t vary much from the R8’s V10. I’ve never seen them both side by side. Based on the differences between the V10 and the V10+ I predicted 50hp out of the JHM tune which we may see when stage 2 hits the shelves. And again, the V10, with most of the roots kits is producing north of 700hp. And they seem to be dead reliable. I think VF has a 900hp kit now too if I’m not mistaken. OEM engine. Strangely, that’s 90hp/cylinder.

I admittedly do not know enough about the RS5’s ECU tables. I’d need to look at how everything is set up first hand to really understand it and I don’t have time to go down that rabbit hole again, LOL. But it’d be nice to really see and understand how the ECU’s logic works and what tables are available to their programmers. And the entanglement of all the sub parameters as well as the TCU.

#37

The V10 motors do have a slightly wider ring pack than the V8 motors as they are making less TDC time per cylinder.so you don’t need to have as close as a ring package on the V10 motors add in slightly less hp per cylinder on the standard V10. Not too sure on the V10+. About 2 years ago I read and had all of the data. I’ll see if I can find it. But the ring packs on the V10s were a bit wider. But using the V10 motors. Take this into consideration. The undergound cars use TT kits on the lambo cars they can only run low boost until they re ring the cars. Then they can un a much higher boost level. That again is due to the rings not the strength of the motor. Same with the RS5 but with 2 less cylinders you need to make more hp per cylinder and you need to have a tighter ring pack.

Keep in mind its not the piston thats different its the ring packs on the piston.

As for the ECUs. I know 100% that JHM has access to all of the tables and every aspect of the ECU. As there tuner uses an actual OEM tool not an aftermarket one like other companies.

JHMs tuner is on this site. PM him. He is usually very accessible. I know many of us have talked to him. Super nice and super helpful along with incredibly knowledgeable.

#38

The other thing I meant to add to my post is keep in mind with the V10 motors adding hp is that you can add more hp per cylinder with less impact.

So if you add 200hp to a V10 your adding 20hp per cylinder.
If you add 200 hp on a V8 its slightly more at 25 per cylinder percentage wise thats a big difference. But its not just that its the TDC time as that allows less cooldown time after a power cycle. Those two things make a big difference in adding power.

#39

What’s his user name? I didn’t realize he’s on this forum. Jake told me a bit about his background and he may have former co-workers who are friends of mine. Really small world!

So essentially I could go with a new ring pack and the OEM pistons… If you could find that info, I’d greatly appreciate it. I would love to read about it! I honestly could see myself acquiring an RS5 piston and sending it off to JE if I decide to push things with this package.

Your comments about Addict…it seems to me, just looking at the hardware, that it’s a pretty solid, well thought out package. I’ve seen a lot of “tribalism” on Youtube regarding Addict and JHM. Tuning aside (I know nothing about their abilities), it looks far more put together than JHM’s SC kit for the S5 which has had it’s issues. There are two individuals that went stage 2 over on Audizine (drama, I know) that had to go elsewhere for a tune and had to change out or upgrade numerous parts to get the kit to work correctly according to them. There was extenuating circumstances with at least one of the guys. Another S5 owner, with 30K on his engine had the JHM kit installed by JHM themselves and it basically blew up within a month with no recourse from JHM. The guy’s been taking apart the car in his garage as he has time. I’ve stayed completely out of that but it does make me take pause. Forums are very much a double-edged sword and no one ever seems to have all of the info to make an informed opinion one way or the other and that’s unfortunate for all parties.

I know more than a few of us RS5 guys had small niggling issues with the RS5 stage 1 tune, especially the cold start cycle and hesitations going from trailing or neutral throttle to WOT. They did release an update but I had the same symptoms come back over time. When I carbon cleaned, I of course disconnected the battery and all the hesitation issues were gone once I buttoned everything back up. I’m now waiting to see if they again creep back up like they did previously.

I’m pretty sure some of the issue was the carbon buildup but I did end up having a hesitation last night while backing up in reverse. So it may be coming back yet again. There are no codes associated with this so I don’t understand why it’s happening. I share this information but it’s usually a one way information path. I share and don’t get any more questions, no request for logs, etc…I have a vested interest in JHM succeeding. I’ve not only paid for their tune but they are really the only ones invested in the RS5. I want to give them my money in exchange for a successful, properly functioning product. Believe you me!

I’ve done logs and I’ve seen timing being pulled at the top end (in various amounts depending on temp) but I’ve not done any logs post-carbon clean. The car definitely feels 20hp stronger post clean which is a good thing, LOL. But I’ve offered to send logs and share information and really never get any interest. Maybe they have people there, other RS5 owners, who are helping out. I think I have evidence they’re working with more than one RS5. The 9K rpm Instagram video shows a car with lower miles than the Red RS5. Could be the new ECU but doubtful as I believe that info is actually kept in the dash module. But I digress!

#40

I never thought about the cool-down between combustion cycles and how it varies with cylinder count! You just blew my mind. I would think it’s just an almost continuous thermal output which the cooling system, oil and coolant, have to deal with whether you’re at 2000rpm or 8500rpm. The heat, unchecked, would continue to build which is why you’d have to properly design the cooling system. I need to do the math and see how many milliseconds we’re talking about between ignition and compression at it’s highest point at redline. I probably need a pretty powerful program to predict the amount of thermal transference though. Interesting stuff none the less.

I do tend to think of it in terms of what a cylinder can support (hp) and understand you’re spreading a certain number of hp across cylinders. I wouldn’t expect the same gains for a V8 as I would for a V10 at the same boost level assuming you’re moving more CFM via the blower as well as the engine’s displacement.

As soon as the weather and my schedule allows, I’m headed back to the track to try and match JHM’s times. Who knows, maybe I’ll be happy with stage 2 depending on what it produces. I know they’re working hard on the tcu tune. TVS says they can tune my transmission for 700nm which would be more than enough for stage 2.