Audi's reply to why our cars don't hit 414BHP

[Les]

I hear what you're saying Silas but I bet the reason you took it to MRC was because you did know it wasn't right?
If you are being passed by VXR's and RenaultSport Meganes......................something's up. If my car was down 100 horse, I'd know it. Running 314 in a car the size of a RS4 would make it difficult to pass flamin' Focus STs surely? Plus I reckon the old 3-8k test would see you at 10 - 11s instead of 8.5 - 9.0?
Each to their own, I'm just foolin' For me its all about how the car runs on the road
I can't see how a machine that sits still in a garage can possibly replicate power output properly, they would need accurately calibrated for each model of car, etc, etc, etc. Physics and mathematics on the other hand can accurately reflect this if you have the right data to process.
Rolling roads are good for when you modify your car to see the difference pre and post but that's about it for me

[esp_mm-270]

Its just that all VAG car figures have always been conservative except this one's bhp. The 0-60 is quicker than stated though

So bhp is lower than stated, but the performance is better than stated... which really matters most? What the car actually DOES, or the bhp figure you can brag about in the pub? To me, it's what the car does (and how it does it makes me smile).

I didn't mention which I thought was more important Dave.

[RIV]

Rolling roads are good for when you modify your car to see the difference pre and post but that's about it for me

fair point I new mine felt flat, and was correct as it was running at 338ps and got it back with 436.6ps and 484nm
I think if your a newbie it's a good idea to dyno to see where it's at, but get your point these cars have never made the claimed power from day one

[Graeme4130]

Fwiw, my old B7 made 365 on the rollers due to carbon build up. After an engine rebuild and new valves etc from Audi, it made 409. It certainly felt quicker (although difficult to tell after 1 month in A6tdi courtesy car) and the throttle response and low rev surge was massively improved

My B8 made the exact quoted 444bhp at the AMD day on <beep> fuel and 11k miles

[ArthurPE]

do the math
a 4000 lb car
with high driveline losses due to awd: 4 1/2 axles, 2 diffs, a xfer gearset
and yet will do sub 5 0-62 and high 12's/108+ in the 1/4 mile
it pulls the Ring ~ as fast as a 997 S (same tires)

8:05 BMW M5, 560 PS (Horst von Saurma 09/12)
8:05 Porsche 997 Carrera S, Walter Roehrl (!) the Master
8:05 BMW M3 E92 Horst von Saurma
8:09 Audi RS4 Horst von Saurma
8:09 BMW M6 E63 Horst von Saurma ( a lighter car with 500 HP) used sport tires
8:13 Mercedes-Benz_C63 AMG Horst von Saurma

these are the only numbers that are relative

[PetrolDave]

Its just that all VAG car figures have always been conservative except this one's bhp. The 0-60 is quicker than stated though

So bhp is lower than stated, but the performance is better than stated... which really matters most? What the car actually DOES, or the bhp figure you can brag about in the pub? To me, it's what the car does (and how it does it makes me smile).

I didn't mention which I thought was more important Dave.

But by saying "all VAG car figures have always been conservative except this one's bhp" you're implying that the bhp figure being below spec upsets you in some way.

I'm with Les on this one - it's time to move on, especially as the history of internal combustion engine shows that power drops with time so it's pretty unreasonable to expect a 5-7 year old car to meet the figures for a brand new (but properly run-in) car.

Our cars, without faults such as vacuum leaks, are faster than the spec - in my opinion that's "end of".

[Awd4]

that is quite compelling evidence that they don't give you 414 standard

And my point is, who cares? The dyno numbers might not match the spec, but the actual performance is better than spec - so what actually matters? Numbers on a data sheet, or real performance?

In my book, it's real performance that matters - others will disagree, but that's fine.

Yep, defo with Dave on that one, given the amount of smiles my car has delivered to me over the last 6 years, i don't feel 'robbed' for a second by Quattro gmbh

[sakimano]

Its just that all VAG car figures have always been conservative except this one's bhp. The 0-60 is quicker than stated though

So bhp is lower than stated, but the performance is better than stated... which really matters most? What the car actually DOES, or the bhp figure you can brag about in the pub? To me, it's what the car does (and how it does it makes me smile).

Bang on

[Rick_RS4]

dont know about you but im more pissed about the fact it only has 1 cup holder, and when its open it covers the dash.

omg my life is over

[ArthurPE]

Its just that all VAG car figures have always been conservative except this one's bhp. The 0-60 is quicker than stated though

I don't believe their numbers are all conservative
I believe they are all within the same tolerance specified by the DIN/ECE and as tested by an independent 3rd party
they are not going to 'give away' HP and not take advertising credit for it

if tested as Audi states
engine dyno
proper air supply
proper fuel
proper atm conditions
and run up to redline, apply load until the engine bogs down to HP peak, then run and record for 30 seconds or more
only then will you get a true power reading

a ramp run on a dyno will not do it. why?
because if the engine can accelerate the load this means it has power that is not being expended (in other words in reserve), and therefore not measured
if it stalls against the load and can't accelerate it has no power in reserve and is at its maximum output
ramp dynos can accuately measure torque in the mid-range but are inaccurate at power peak, or past torque peak
becasue they are constantly accelerating the load til then, and F = ma, so we know force/thrust, and with gears/tire diameter, etc. can calculate HP

[adsgreen]

dont know about you but im more pissed about the fact it only has 1 cup holder, and when its open it covers the dash.

omg my life is over

Hah - with you there.
I also hate that te one that they do give you never seems to quite fit anything.

As for the topic - I've got tyres that are on the verge if needing changing, monsoon conditions, cool 5 degree ambient... Coupled with Quattro and a v8. Omg - I had so much fun

[adsgreen]

Its just that all VAG car figures have always been conservative except this one's bhp. The 0-60 is quicker than stated though

I don't believe their numbers are all conservative
I believe they are all within the same tolerance speciified by the DIN/ECE and as tested by an independent 3rd party
they are not going to 'give away' HP and not take advertising credit for it

if tested as Audi states
engine dyno
proper air supply
proper fuel
proper atm conditions
and run up to redline, apply load until the engine bogs down to HP peak, then run and record for 30 seconds or more
only then will you get a true power reading

a ramprun ona dyno will not do it. why?
because if the engine can accelerate the load this means it has power that is not being expended, and therefore not measured
if it stalls against the load and can't accelerate it has no power in reserve and is at its maximum output

+1 - I like dyno runs but they are a pinch of salt.

[ArthurPE]

here's another way to look at it
in the 'olden days' actual dynomometers were used
the engine spun a generator connected to a resistive load bank (matched to the generator maximum output and adjustable, usually blocks of R and a rheostat for trim)
the current and voltage were accurately measured and P = i x V in W, 1 Hp = 746 W
if the engine was not held steady at peak power, and was changine speed, the readings are not accurate due to transients/reactance of the generator, etc.

[sulli]

do the math
a 4000 lb car
with high driveline losses due to awd: 4 1/2 axles, 2 diffs, a xfer gearset
and yet will do sub 5 0-62 and high 12's/108+ in the 1/4 mile
it pulls the Ring ~ as fast as a 997 S (same tires)

8:05 BMW M5, 560 PS (Horst von Saurma 09/12)
8:05 Porsche 997 Carrera S, Walter Roehrl (!) the Master
8:05 BMW M3 E92 Horst von Saurma
8:09 Audi RS4 Horst von Saurma
8:09 BMW M6 E63 Horst von Saurma ( a lighter car with 500 HP) used sport tires
8:13 Mercedes-Benz_C63 AMG Horst von Saurma

these are the only numbers that are relative

That time would have been set by a well tuned Rs4, certainly one running peak power. If most Rs4s lose this power and drop 50 or so BHP, then that's an issue as such a time would not be set by them. If I owned an RS4, Audis answer, above, would not satisfy me as it's overlooking the clear problem and coming up with excuses.

[ArthurPE]

do the math
a 4000 lb car
with high driveline losses due to awd: 4 1/2 axles, 2 diffs, a xfer gearset
and yet will do sub 5 0-62 and high 12's/108+ in the 1/4 mile
it pulls the Ring ~ as fast as a 997 S (same tires)

8:05 BMW M5, 560 PS (Horst von Saurma 09/12)
8:05 Porsche 997 Carrera S, Walter Roehrl (!) the Master
8:05 BMW M3 E92 Horst von Saurma
8:09 Audi RS4 Horst von Saurma
8:09 BMW M6 E63 Horst von Saurma ( a lighter car with 500 HP) used sport tires
8:13 Mercedes-Benz_C63 AMG Horst von Saurma

these are the only numbers that are relative

That time would have been set by a well tuned Rs4, certainly one running peak power. If most Rs4s lose this power and drop 50 or so BHP, then that's an issue as such a time would not be set by them. If I owned an RS4, Audis answer, above, would not satisfy me as it's overlooking the clear problem and coming up with excuses.

it was run by a well used magazine test car with 15k miles on it, HARD miles
not 'tuned', these cars are self-tuned, no adjustments other than filters, plugs, etc.
as long as the AFM, O2 sensors and fuel pressure sensors are good, it is tuned

sport auto always lists the mileage of the car tested