B7 saloon dynoed - 308 hp at the wheels, 320 lb ft torque

[SR71]

Alex,

Engine dyno stats might be the "gold standard" but its a con if the average owner is then not at liberty to ascertain whether his car meets those specifications....because, of course, in order to do so he has to get his block out of the car and take it to a mad-scientist who just happens to have an engine dyno in his back shed.

Losses from car to car should not vary hugely if the manufacturing process is controlled, so there should be a slight spread in the figures at the hub, but these we can easily access.

I reckon their might be some obscure Vagcom settings that enable what seems like a particularly sophisticated transmission control system to be "properly" switched off, thereby rendering reliable results.

I don't believe individual car behaviour should vary on the dyno depending on whether the ESP or TC is switched on and off.

[t_urbo]

Well, as promised I had my run at WRC today and the results aren't the saem as yours Alex. My RS actually performed better on Shoot_8 rather than Shoot_44 because WRC's Shoot_8 program is designed for 4WD V8's
Shoot_8


and Shoot_44



Which by DD extrapolation would have brought up



Interesting because Shoot_8 had higher roller loss but more power. And the runs were done in 3rd and 4th gear and the loading up to 3000rpm in third was terrible, 4th produced better results so long you didn't bounce off the r/r speed limiter which was tricky because 8000 rpm equated to 127 mph and the r/r limit was 128mph!

So looking at Shoot_8 (the first graph) and having phoned someone at Audi UK who said that through a r/r there could be up to 31% transmission loss would give a figure from my results of 414.3bhp and 322 ft.lbs as seen on the graph.

I also asked Chris about the other RS4's he had dyno'ed and none have produced the quoted figures. And when remapped they have seen improvements from 10bhp in MY07 cars up to 50bhp on early RS's, there is not set improvement.

So we are no further forward really, but I'm happy with the figures as it is about what I thought and it's still a great car. Had fun trouncing a Civic Type R on the way their along the A43 this morning!

Shoot 8 is showing a higher output in 3rd gear than shoot 44 is in 4th gear which would suggest that shoot 8 is 'massaging the figures' somewhat because you should be seeing your biggest gains in gears 4-6 not 1-3.
There is around a 20Hp difference between gears 1-3 and 4-6, which would equate to your car having an output of about 440 Hp in 4th gear in shoot 8 mode.
Shoot 44 figure look more realistic.
Good info though.

[alex_123_fra]

Good info everyone,

I'll certainly post more results up after I get a chance to dyno again at WRC in various modes and gears. Hopefully, in time, the more info filters through, the better our understanding will be of just how to get the best out of these cars on a dyno.

Alex

[P_G]

Well, as promised I had my run at WRC today and the results aren't the saem as yours Alex. My RS actually performed better on Shoot_8 rather than Shoot_44 because WRC's Shoot_8 program is designed for 4WD V8's
Shoot_8


and Shoot_44



Which by DD extrapolation would have brought up



Interesting because Shoot_8 had higher roller loss but more power. And the runs were done in 3rd and 4th gear and the loading up to 3000rpm in third was terrible, 4th produced better results so long you didn't bounce off the r/r speed limiter which was tricky because 8000 rpm equated to 127 mph and the r/r limit was 128mph!

So looking at Shoot_8 (the first graph) and having phoned someone at Audi UK who said that through a r/r there could be up to 31% transmission loss would give a figure from my results of 414.3bhp and 322 ft.lbs as seen on the graph.

I also asked Chris about the other RS4's he had dyno'ed and none have produced the quoted figures. And when remapped they have seen improvements from 10bhp in MY07 cars up to 50bhp on early RS's, there is not set improvement.

So we are no further forward really, but I'm happy with the figures as it is about what I thought and it's still a great car. Had fun trouncing a Civic Type R on the way their along the A43 this morning!

Shoot 8 is showing a higher output in 3rd gear than shoot 44 is in 4th gear which would suggest that shoot 8 is 'massaging the figures' somewhat because you should be seeing your biggest gains in gears 4-6 not 1-3.
There is around a 20Hp difference between gears 1-3 and 4-6, which would equate to your car having an output of about 440 Hp in 4th gear in shoot 8 mode.
Shoot 44 figure look more realistic.
Good info though.

Shoot_44 however isn't realistically set for a RS4 type vehicle, the 44 meaning 4 cylinder 4 wheel drive. It allows higher accelerations rates due to turbo spooling, so it's a tough one to tell which is best. Hence why shoot_8 was WRC's preferred program as they had said it had been altered slightly to account for a 4WD V8 car. But then it could have as easily massaged the figures like you say.

It's still bloody quick on the road!

[SR71]

I notice in the September Issue of Evo Magazine, where they compare the C6 RS6 versus R8, the R8 dynos at 400.5bhp. The RS6, however, dynos at 486.4bhp, almost 100hp down on the claims...

It is clear from the acceleration figures quoted that riding in a RS6 will not feel any faster than the R8/RS4 until you are doing over 100mph.

However, the comparing both cars figures with the F430 Scuderia - well they're both blown into the weeds by that car! It does, however, cost £172K.

Does anyone actually know of a B7 that has dynoed close to the claimed 414hp prior to a remap?

[reevesroadster]

Id be happy to get mine dynoed - its a stock Nov 06 model with 18000 on the clock.

Being a complete novice in the wordl of dynos (even having read these posts) is there a defacto standard setup for a rr test that we should all adopt so we can compere results more equally?

Is it also noting how the car was originally "run-in' and maintained - ie, driven really hard or carefully during the run-n period, oil changed frequently etc?

[S4INT]

Does anyone actually know of a B7 that has dynoed close to the claimed 414hp prior to a remap?

Mine dyno'd at 395bhp stock, which is one of the highest I've heard of. Still well down on the manufacturers claims, but not as bad as some on here.

[Brooner]

What i don't unerstand is when i go my B5 dnyno'd totaly standard i go the correct torque 320 and the Bhp was 409 well over the stated 380 so why is i with the B7 there no were near the quoted 414???
link to my dyno figyures fro my old B5 http://www.rs246.com/index.php?name=pnCPG

[Marcus-RS4]

Could it have something to do with the 60/40 split Vs the B5's 50/50??

[SR71]

S4INT,

Where did you get the car RR'ed?

[P_G]

Could it have something to do with the 60/40 split Vs the B5's 50/50??

That is something to do with it and that B5 cars were on version 4 IIRC of ESP whereas B7's are on version 9. I have seen a v10 S8 dyno'ed and it suffered a huge power loss and the r/r people did even intimate that these cars can tell when they are on a slippery surface / rollers and turn the wick down as part of the system so a true value cannot be taken.

There is also the learned values of the ECU's, dependent on how you drive will affect power delivery and this may affect the plots.

[PetrolDave]

RR tests can never be a true measure of the engine power & torque since you have to (gu)estimate the transmission losses.

The only real way to measure the power & torque of an engine is to take it out of the car and put it on an engine dyno - and that ain't a cheap or easy thing to do!

[P_G]

Very true Dave and even if all RS4 owners go the the same r/r, there would be factors that alter the readings per car.

[S4INT]

S4INT,

Where did you get the car RR'ed?

It was done at DMS on their Dyno dynamics RR.

[SR71]

Yeah we all know the limitations of the RR.

With respect to the B5's, I'd imagine the reason why everyone who dynos their B5 these days gets a relatively good result with regards to the stock quoted power is that RR operators now have a good idea of what the transmission losses really are.... Statistically, you dyno a couple of 100 cars and based on their output at the wheels you can work backwards from the quoted power to give an idea of the flywheel power.

However, when you've only dynoed a few B7's, you measure the power at the wheels, and then work backwards from the quoted power to build up an idea of the transmission losses, use that figure and unless you've thought about it, you're none the wiser.

The more of us who get our cars RR'ed, the better an idea of the true transmission losses we'll get.

Judging by what I've read, the spread of supposed losses is between 20-30% which is a ~40hp spread! Ridiculous.

Why bother?

Nevertheless, we know an owner who managed to get their car returned to Audi for "failing to deliver the quoted power" (sic).

Personally, I think the car is just about delivering the quoted power judging by the speeds it generates at the track and the times over the 1/4, but nevertheless it'd be nice to build up some solid information about why the car is failing to peform on the RR.

The C6 RS6 in the magazine article above was obviously unhappy on the RR, P_G has seen a S8 fail to deliver so I suspect inspite of switching the ESP off, there is still some electronic wizardry f**king with the results....