Pictures of my inlet ports....

[sonny]

rs246 used to be pretty good.

It is, and always will be a very good Audi forum, you just have to ignore "some" of the PAP that gets posted.

[ArthurPE]

so it's my fault that you act inappropriately?

lol, how about accepting responsibility for your own actions

no one said you are 'liars'
believe what you like...
I'll do the same
I'll offer my 'proof', you do the same

but don't blame me for the man you are...

It's a shame the conversation has gone this way. rs246 used to be pretty good.

Unfortunately Arthur brings out the worst in people (me included). If you look at the other sites, the ones that Arthur is on, most threads turn this way. I'm not having a go at Arthur, he is passionate, same as those on here.

I get worked up when he states the theory behind it says it shouldn't happen, but uses that as a way to say we, who have gone through it all in practice, are basically liars.

I think most get the theory, and expect that it shouldn't happen (and I'm glad he can provide it) but I think at least have the common courtesy to accept what we have experianced is different to what it should be like.

Anyway, hopefully things improve around here.

[ArthurPE]

and yet, not a single attempt at an answer
instead we dwell on the 'drama', I think people like a 'problem', more than a 'solution', especially if there is no 'problem', so there can't be a 'solution', lol

1) how does it <beep> timing? what mechanism? detonation, pre-ig, mis-fire?

2) how can the fuel NOT be mixed
1500 psi, atomized, velocity >1000 ft/sec >>>> air stream, thorough mixing...
> higher than it's vapor pressure, soon as injected, vaporizes immediately...like releasing water >212F under pressure >>> gas/vapor
piston speed > air speed (90 vs 70 ft/sec or so), actual a vacuum pump
shot into the stream as it passes the nozzle, mixes with entire charge...
compressed o 12.5:1 reducing any gradient differences by the same factor

3) two cars recently cleaned, both modded
8.4 or socorrected, the same as all uncleaned, unmodded cars

[ArthurPE]

more food for thought:
how much fuel is inject per stroke (7800 rpm, full load, A/F ~ 12/1, std air density, vol eff ~ 0.95) in grams converted to cc
what is it's volume at 100 atm 100F+? and at 1 atm 200F?
how far would the injector shoot the fuel at 1500 psi if not constrained by the cylinder?

I think if you look at these values you can convince yourself mixing (leading to detonation) won't be an issue

[2manytoys]

Arthur, my point again is that; yes, the theory behind it may suggest that it doesn't happen. Why do you continue to post it up? Yes, we get it. It shouldn't happen based on your numbers. ok. I really do accept that as the theory (I don't know any better).

My point is that in practice, for what ever reason, the results are very different. There is something that you are missing in your calculation. If it was that easy to get 100hp per litre out of a NA car, why arn't all manufactures doing it.

I suspect, in practice "the sum is greater than the parts". I've also said this before; you have seen many workshops (not just including Gostford European), but MRC and even APR notice the impact of carbon on an engine (gee, even Audi Australia are aware and helping to resolve the problems). These are very respectible guys from what I understand. I know APR wasn't aware of it initially as they tuned a car with loads of carbon and then posted the Dyno. It wasn't until there was a bunch of guys that "knew" the curve wasn't right that they went back and posted up a car that did have a proper power curve.

Ok, can I ask; is your agenda to refute the claims by the people that post up, or is it to understand why this is happening? If it is to simply refute the claims, that's ok, but if it is to understand, maybe you can ask me and the others that have experianced carbon buildup some questions to help us all understand why it does what it does (that's the rs246.com way)

[ArthurPE]

the theory PROVES it can't cost more than 2% power, let alone 100 HP

in reality they aren't different, only manipulated, falsely attributed or misunderstood

2 recent cars, both modded, both cleaned
both ~8.5, same as stock uncleaned cars...
explain?

I know it isn't happening, I try to explain why, and debunk all the misinformation or misunderstanding being bandied about...
I already understand the mechanisms at play...that's why I know it can't happen...it's like saying if you drop a brick it will fall up...

answer any one of these:
1) how does it <beep> timing? what mechanism? detonation, pre-ig, mis-fire?

2) how can the fuel NOT be mixed
1500 psi, atomized, velocity >1000 ft/sec >>>> air stream, thorough mixing...
> higher than it's vapor pressure, soon as injected, vaporizes immediately...like releasing water >212F under pressure >>> gas/vapor
piston speed > air speed (90 vs 70 ft/sec or so), actual a vacuum pump
shot into the stream as it passes the nozzle, mixes with entire charge...
compressed o 12.5:1 reducing any gradient differences by the same factor

3) two cars recently cleaned, both modded
8.4 or socorrected, the same as all uncleaned, unmodded cars

Arthur, my point again is that; yes, the theory behind it may suggest that it doesn't happen. Why do you continue to post it up? Yes, we get it. It shouldn't happen based on your numbers. ok. I really do accept that as the theory (I don't know any better).

My point is that in practice, for what ever reason, the results are very different. There is something that you are missing in your calculation. If it was that easy to get 100hp per litre out of a NA car, why arn't all manufactures doing it.

I suspect, in practice "the sum is greater than the parts". I've also said this before; you have seen many workshop (not just including Gostford European), but MRC and even APR notice the impact of carbon on an engine (gee, even Audi Australia are aware and helping to resolve the problems). These are very respectible guys from what I understand. I know APR wasn't aware of it initially as they tuned a car with loads of carbon and then posted the Dyno. It wasn't until there was a bunch of guys that "knew" the curve wasn't right that they went back and posted up a car that did have a proper power curve.

Ok, can I ask; is your agenda to refute the claims by the people that post up, or is it to understand why this is happening? If it is to simply refute the claims, that's ok, but if it is to understand, maybe you can ask me and the others that have experianced carbon buildup some questions to help us all understand why it does what it does (that's the rs246.com way)

[2manytoys]

oh my god, so we are liars. Where did you get 100hp loss from too?

Anyway, you are here just say the theory behind it says it doesn't happen. So it's not a meaniful discussion. In that case I'll stick to the other forums where the members actually help, and are not overrun by Arthur Buildup. Enjoy

[ArthurPE]

I did not say liars, you did, I would not use that word...mistaken is a better choice...

for me to 'help' you I have to believe you are correct and it costs power, I believe it doesn't...

stock wheel 320 or so
yours 260 or so

prorated to crank 420/320 x (320 - 260) ~ 80 HP in you case
others have said up to 100 over time...
some have said <2% or <8 HP

no one has even attemped to answer: please give it a shot
1) how does it <beep> timing? what mechanism? detonation, pre-ig, mis-fire?

2) how can the fuel NOT be mixed
1500 psi, atomized, velocity >1000 ft/sec >>>> air stream, thorough mixing...
> higher than it's vapor pressure, soon as injected, vaporizes immediately...like releasing water >212F under pressure >>> gas/vapor
piston speed > air speed (90 vs 70 ft/sec or so), actual a vacuum pump
shot into the stream as it passes the nozzle, mixes with entire charge...
compressed o 12.5:1 reducing any gradient differences by the same factor

3) two cars recently cleaned, both modded
8.4 or socorrected, the same as all uncleaned, unmodded cars

oh my god, so we are liars. Where did you get 100hp loss from too?

Anyway, you are here just say the theory behind it says it doesn't happen. So it's not a meaniful discussion. In that case I'll stick to the other forums where the members actually help, and are not overrun by Arthur Buildup. Enjoy

[2manytoys]

I don't know the answers to your questions, I'm not a mechanic, that's the whole problem. I'm not going to second guess why, or why not, or even why it doesn't make sense, it just happened.

It doesn't really matter anyway, because all I know is that when the valves were cleaned by Gosford European the car had it's power back. That's why I've been posting it forums. In fact, I posted the problem way before we found the cause. You read the thread on Audizine, you can see the process that I went through.

Again, I understand your point, but in practice, for whatever reason (in my case) carbon caused the loss. Maybe it's the temps in Oz, maybe it's the high humidity, maybe it's because our toilets flush in the opposite direction, I don't know, all I can say is it is what it is.

I'll have VAGCOM tomorrow so maybe I can get some logs for you to look at??

[2manytoys]

I've been messing around with Vagcom a bit and have noticed this:

When I first had the problem, my timing advance was between 9 & 13 degrees. The car was obviously pretty low on power.

At 20 degrees advanced timing, the surge of power at 5500/6000rpm is only just there (you can feel it and if you didn't know better you'd think it's pretty good).

At 30 degrees advanced timing, the surge is "massive". The car pulls hard.

This was all done in second gear. I'd be interested to read what the timing is from a car that has 40,000kms+ and never been cleaned. Can anyone check and post up the results for me? If you can let me know your intake temps (from Vagcom too) that would be awesome.

I live in hope that this problem really doesn't impact every car.

[Caillin]

I hate to necro what has clearly been such an imflamatory thread, but just wanted to mention that I'm starting to see the same symptoms that 2manytoys had also experienced. I'm also from Oz, but a much hotter/humid part (North Queensland). Over the last week or so, I've noticed pinging (whether it be from pre-ignition or detonation) on very light throttle inputs. On top of this, I had a single case of much stronger pinging with the engine fairly heatsoaked, and in 6th gear heading up a slight incline.

I've been spending quite a bit of time troubleshooting what I'm sure is a power deficiency since I've owned the car (about 14 months ago). My Vagcom logs are showing peak timing advance of around 22degrees, and timing <beep> of up to 12 from about 4k rpm onwards.

I've comprehensively confirmed that a) I have no vacuum leaks b) the intake runner flaps are operating perfectly (logged) c) the airbox flap wasn't activating, however I subsequently replaced it with a new one and now operates perfectly d) car has new plugs e) car has new air filter f) car has new fuel filter.

So, like 2manytoys, I'm down to three symptoms: Lack of power (as evidenced by 3k-8k logs), pinging in certain scenarios and up to around 10 degrees of timing <beep> when compared to other logs I have gathered from other forums and around the place.

The big difference between our cars though, is that I'm coming up on 160k kms, and have no idea whether it's ever had a carbon clean. I'm going to be organising a carbon clean over the next few months and will make sure to be doing thorough datalogging before and after. I think 2manytoys ended up with a valve stem seal issue which was introducing more oil than normal into the intake tract and that was exacerbating his issue with much lower mileage.

I also can't see how carbon buildup could cause that amount of timing to be pulled or the pinging, but will be interested in the results once I have them. Would be also interested if any other owners have noticed any similar issues now that the B7 platform is starting to get some age on it.

For those that care, I've detailed most of my journey up until this point on the AR forums: http://audirevolution.net/forum/index.php?topic=2603.0

[sync24]

Caillin, drop a mail to doug at MRC Tuning, Banbury, UK and explain your symptoms he may be able to diagnose it for you. There is nothing he does not know about RS4 B7's

[Caillin]

Thanks for the reply sync24. I'm not going to waste anyone's time yet until I get a carbon clean done. Whether it affects the car that much is still up for debate, on a car that potentially hasn't had a clean done in 160k kms, I'd be silly not too give it a good clean after doing all the other maintenance items and log before and after. Seeing the amount of debate this issue has sparked across countless forums, I'm inclined to run before and after dyno runs along with the logs, just for the interests of getting some more data points.

If I hit a brick wall, then I'll definitely see if someone like Doug can help out, but I'd be more comfortable paying for his time.