RS4 B7 Stated Power claim of 420ps

[HYFR]

ok ok, i didnt ignore it, just didnt notice it

its always more difficult in text to get across the meaning

[Sims]

ok ok, i didnt ignore it, just didnt notice it

its always more difficult in text to get across the meaning

[SimonC]

if the DP increases across the valve face, just crack the throttle a tad more, problem solved...the throttle is oversized, that's why they have a rev limiter, because the throttle is NOT the limiting factor...but that is moot, because you are pumping (drawing) into a closed system with a positive dispacement pump! forced by atm pressure, neither of which change...

Are you sure? Isn't the inlet manifold under vacuum during acceleration? Surely a restriction in the flow of air into the cylinder will reduce the volume of air (at atm pressure) in that cylinder when the inlet valves close? Motorsport engineers are obsessive about reducing the slightest obstructions to inlet efficiency. It therefore seems logical that an engine with comparable piston speeds is likely to be affected by carbon build-up. I concur that when you are pumping air into the cylinder then such issues are less important, but these engines are not forced-induction and therefore, at maximum revs, the carbon build-up is a spanner in the works.

[Sims]

if the DP increases across the valve face, just crack the throttle a tad more, problem solved...the throttle is oversized, that's why they have a rev limiter, because the throttle is NOT the limiting factor...but that is moot, because you are pumping (drawing) into a closed system with a positive dispacement pump! forced by atm pressure, neither of which change...

Are you sure? Isn't the inlet manifold under vacuum during acceleration? Surely a restriction in the flow of air into the cylinder will reduce the volume of air (at atm pressure) in that cylinder when the inlet valves close? Motorsport engineers are obsessive about reducing the slightest obstructions to inlet efficiency. It therefore seems logical that an engine with comparable piston speeds is likely to be affected by carbon build-up. I concur that when you are pumping air into the cylinder then such issues are less important, but these engines are not forced-induction and therefore, at maximum revs, the carbon build-up is a spanner in the works.

Two Engineers, two opinions.

This, regardless, requires a third - from Audi. I will consider how I elicit this (for my own sake) in a positive manner, and which hopefully stops for me (as the OP) the discusions, doubt, arguments etc.

[ArthurPE]

all you guys who hate your car (among other things) should start a new forum...
'audi haters les miserable' or 'he man audi haters club'

there is enough crap (real crap, the wars, haiti, etc.) to 'worry' about, I come here for a diversion, not to listen to a bunch of well to do guys moan about their imaginary issues with their expensive hipo cars...although it mildly amuses me, it also makes me sad for the human race that we biotch about things of absolutely no consequence...and don't even exist!

it is a sad state of affairs...we fret depsosits while others have amputations without anesthesia or seek a piece of rat meat to feed their kids...get over it...

all the time, thought, effort and $$$ wasted on this non-issue could have put to good use...we could have FED someone or rendered medical aid, or housed them...it's embarressing

just drive the damn car (it's only a CAR!!!!) and get on with your lifes

Calm down dear

I'm not the one who needs a dose of thorazine
I don't have car anxiety disorder, lol
oh woe is me, my hipo car has a pimple? whatever shall I do!

[ArthurPE]

could just be an element different culture between us brits and USAians

I accept that we have more culture

have you seen some of the US forums! they proper lay into one another!

No, the US folk seem to like like fighting.

yes but posts like that are just as bad as what your accusing of

I like Aurthers posts, its like being in a science lesson

being two faced knows no national boundries
you see that, he doesn't...

[ArthurPE]

Are you sure? Isn't the inlet manifold under vacuum during acceleration? Surely a restriction in the flow of air into the cylinder will reduce the volume of air (at atm pressure) in that cylinder when the inlet valves close? Motorsport engineers are obsessive about reducing the slightest obstructions to inlet efficiency. It therefore seems logical that an engine with comparable piston speeds is likely to be affected by carbon build-up. I concur that when you are pumping air into the cylinder then such issues are less important, but these engines are not forced-induction and therefore, at maximum revs, the carbon build-up is a spanner in the works.

what is 'vacuum'? it's relative
it's actually under pressure...
atm pressure is 14.7 psi
with the throttle closed at idle an engine pulls ~20 in hg ~ 10 psi, so the manifold is still under positve pressure...if it weren't air wouldn't flow into the cylinder...the vacuum goes to ~0 when the throttle is open...

the engine will take the same amount of air with or without obstruction...
it's the throttle that limits airflow, nothing else...it is so much larger than the valves it feeds it they have little influence, or in control valve terminology, 'throttling' range...

if the valve orifice x lift were restricted, it is not, because it is much larger than the valve seat opening, but if it were the air velocity will increase and the Q remain the same...
you would have more DP across the valve, but all that needs to happen to offset that is to crack the throttle...

btw: the air vel into a cylinder (RS4, 7800 rpm) is ~110 ft/sec, speed of sound ~1130 ft/sec...it is normal flow, nothing special..

to lose 15% HP (60/414) you'ld have to lose 15% of the air...

T = V x Pme/4Pi
this defines an engines torque...period
V = displacement
Pme = mean effective pressure ~ comp ratio x vol eff...

P = T w (w = speed 2Pi rev/sec)

these are the facts...they apply to all, 'believers' and 'independants' alike
there are still folks who believe cold water boils faster than hot and if you drop a cue ball vs bowling ball off a building the bowling ball will hit first...

area of the valve opening ~ 0.78 in^2
area formed by the torus of the opening ~ 3.14159 x 1 x 0.5 ~ 1.57 in^2
it's twice as large (not a coincidence)
if we have 4mm (twice of what we normally see) of deposits ~ 3.14159 x 1 x 0.35 ~ 1.07 in^2
STILL much larger...

don't sweat it...Audi, Porsche, VW, Ferrari, BMW, et al have far greater minds than us building these things, too many 'junior engineers' trying to second guess them with junk science...

if some believe so much in this, convince a lawyer and sue, pull the engine, dyno, clean, then dyno again (times 20 or 30), have it all certified by an engineer...then make your case to Audi with a 3rd party (judge/jury/arbitrator) as the decider...if you win you can recoup all the associated costs...IF you win...therein lies the rub...

anything else is pointless bellyaching

[pad125]

....all of what he said!

Once again the doors close firmly on the power output of the RS4....Phew!

[HYFR]

if some believe so much in this, convince a lawyer and sue, pull the engine, dyno, clean, then dyno again (times 20 or 30), have it all certified by an engineer...then make your case to Audi with a 3rd party (judge/jury/arbitrator) as the decider...if you win you can recoup all the associated costs...IF you win...therein lies the rub...

this is the ONLY proof

not a bl**dy RR !!!

[Sims]

....all of what he said!

Once again the doors close firmly on the power output of the RS4....Phew!

No.

In the words of Joschka Fischer " I am not convinced". Subsequent US diatribe,snide remarks, insults only found favour with a very few brown nosed's.

There is smoke here, there are many different opinions, there are conflicting RR reports, AFAIK this is relatively new technology. I am confident Audi will resolve this issue, even if it eventually turns out to be not that serious an issue. VDT

http://www.rs246.com/index.php?name=PNp ... hlight=drc

Audi's written opinion about the DRC was there is no mechanical problem. And now? And yet there are the misguided who still are in denial on this too - perhaps they should do a search on DRC on this very forum, but here's something to get them going.

http://www.rs246.com/index.php?name=PNp ... hlight=drc


Different opinion's, however, make this forum valuable.

As I have stated previously, I shall make my own inquiries directly with Audi.

[HYFR]

lets suppose its true.

this would effect ALL FSI audi's surely?

1.6 FSI
1.8 TFSI
2.0 FSI
2.0 TFSI
3.2 FSI

so it wouldnt be a problem only effecting a small RS population, it would be across ALL their models.

there would be uproar if the # 2 ranked premium manufacturer in the world had produced a shed load of cars that do not meet their rated output

I've got an idea! my sis has a 1.6 A3, non FSI. My gfnd a 1.6 FSI A2. I should put them both on the rollers and see what happens !

[Sims]

lets suppose its true.

this would effect ALL FSI audi's surely?
so it wouldnt be a problem only effecting a small RS population, it would be across ALL their models.!

It seems only RS4 owners have raised this issue - perhaps because the 4.2 8 cylinder is different to the rest??? I am asking

there would be uproar if the # 2 ranked premium manufacturer in the world had produced a shed load of cars that do not meet their rated output
!

These things happen, and not just to Audi. Didn't some of the guys on here try to get the DRC issue on wtachdog? Bad publicity, on any product, only lasts a a short while. And the situation here is not drastic, it's just unsatisfactory.

I've got an idea! my sis has a 1.6 A3, non FSI. My gfnd a 1.6 FSI A2. I should put them both on the rollers and see what happens !

RR's & on two unrelated cars ? Waste of money for for what we are trying to ascertain.

[HYFR]

I've got an idea! my sis has a 1.6 A3, non FSI. My gfnd a 1.6 FSI A2. I should put them both on the rollers and see what happens !

RR's & on two unrelated cars ? Waste of money for for what we are trying to ascertain.

they both have a rated power of 110 bhp IIRC

[BlingBling]

lets suppose its true.

this would effect ALL FSI audi's surely?

1.6 FSI
1.8 TFSI
2.0 FSI
2.0 TFSI
3.2 FSI

so it wouldnt be a problem only effecting a small RS population, it would be across ALL their models.

there would be uproar if the # 2 ranked premium manufacturer in the world had produced a shed load of cars that do not meet their rated output

I've got an idea! my sis has a 1.6 A3, non FSI. My gfnd a 1.6 FSI A2. I should put them both on the rollers and see what happens !

The problem may well impact other cars. However, with most of those engine mentioned any power loss would not be felt.A 10% loss in a 4.2 RS4 is 41bhp whereas its 11bhp for a 1.6. Would you miss 11bhp? No. 41bhp? Possibly.

[ArthurPE]

....all of what he said!

Once again the doors close firmly on the power output of the RS4....Phew!

No.

In the words of Joschka Fischer " I am not convinced". Subsequent US diatribe,snide remarks, insults only found favour with a very few brown nosed's.

There is smoke here, there are many different opinions, there are conflicting RR reports, AFAIK this is relatively new technology. I am confident Audi will resolve this issue, even if it eventually turns out to be not that serious an issue. VDT

http://www.rs246.com/index.php?name=PNp ... hlight=drc

Audi's written opinion about the DRC was there is no mechanical problem. And now? And yet there are the misguided who still are in denial on this too - perhaps they should do a search on DRC on this very forum, but here's something to get them going.

http://www.rs246.com/index.php?name=PNp ... hlight=drc


Different opinion's, however, make this forum valuable.

As I have stated previously, I shall make my own inquiries directly with Audi.

so all who see the logic are 'brown nosers'?
you are the one slinging the backhanded insults, all that shows is a lack of balls you choad...what a loser

go ahead and contact Audi:
let them know you believe they have committed criminal fraud by over rating the engine...let us know how that works out for you...

or better yet, put your $$$ where your mouth is, ante up and sue, do the testing, let's see the reulsts...