RS4 B7 Stated Power claim of 420ps

[Sims]

Clearly there is a lot of debate about how much power the car outputs.

Stated claim is 420ps, but someone at MRC mentioned some good cars make 370 or 380ps, whilst the mediocre ones make 300-330ps.

Has anyone ever pursued this with Audi, for it sounds like a misrepresentation. Don't get me wrong, I think even 300ps is plenty, but if you buy a beer which claims 5% alcohol, and it is only 3%, you would feel a bit pissed off.

I have done a search but could not find anything specific

[Dom81]

There's loads of posts about this. Varsity got his money back, but most are more than happy with the performance (and no-ones had the engine on a test bed to disprove Audi's claims)

[HYFR]

think the key issue is being able to prove it, so it stands up in court so to say....jsut putting it on a rolling road is not proof as there are so many variables

whatever BHP my car is putting out, im happy with it, of course i want it to do what it says on the tin, but im not going cry over it if i put it on a RR and it puts out 350, unless it drove like a mini

[Sims]

think the key issue is being able to prove it, so it stands up in court so to say....jsut putting it on a rolling road is not proof as there are so many variables

so if you put two 4wd Audi's on a rolling road, and one makes close to the power stated, and the other does not...

whatever BHP my car is putting out, im happy with it, of course i want it to do what it says on the tin, but im not going cry over it if i put it on a RR and it puts out 350, unless it drove like a mini

That is rather simplistic. What is the point to making a claim about power, and then not delivering. People who readily accept the shortfall, because of other redeeming features, are perhaps encouraging this deficiency for where does it stop next.

[P_G]

Who says it is not delivering? A rolling road?

The only way you will know what your car is doing is by paying for the engine to be taken out and put on a bench dyno. If it is down in those circumstances then you have a case.

Otherwise factors influencing rolling road are numerous inidicated by when we have 15-20 RS4's on one and the same dyno at Paramount. factor in engine temperature, wheel rolling radius, tyre pressure, gear box oil temperature, atmospheric pressure, ambient temperature, conversion factros, consistency of roller output, car age and mileage

This is why r/r's are only a good baseline indicator from which to work on, not an absolute. If you used the r/r argument it is blown out the water in my case because my car can dynos anywhere between 358 and 396 bhp with a vacuum leak present in all cases. So how does it gain (or lose) 38 bhp?

Best way to measure is get yourself a Racelogic unit or simpler still, do the 3000-8000 rpm in third test and time how long it takes for your car to do that. If around 8 seconds then I'd suggest your car is near the mark.

[stumpyrs4]

Not having entered this debate before, only acknowledging that there are 'issues' with the B7 unit. I think it really should be taken up with Audi as there is such common/widespread under performance figures noted.

Yes the car's do I'm sure perform well on the road, even if they have 'only' 300ps, but imagine how much better it would be with an additional 100ps on tap? That's what you've bought and for some it may be the only reason they bought the car...

[P_G]

Thing is though stumpy67, having been up against E90 M3's, an IS-F and an E39 M5 who were all trying they don't get away from you in an RS4. I doubt a 300ps car could do that?

And what are the 'issues' with the B7 unit? Valve carbonisation? It is an acknowledged subject but again there is not definitive and repeatable evidence to say how much, if at all, this is an issue and how it affects performance. I have seen up to 10% like everyone else who reads this forum but it is not universal.

[Sims]

Thing is though stumpy67, having been up against E90 M3's, an IS-F and an E39 M5 who were all trying they don't get away from you in an RS4. I doubt a 300ps car could do that?

But would a 420ps car get past them with ease? or are you suggesting none if these make the stated power. I have not seen any threads about this for the E9? M3's or the E39 M5.

Plese note I am here because I like the B7 RS4 concept.

[HYFR]

i have been up against a 59 plate M3, on a private road
straight stretch, pure foot down....it was neck and neck, but in 4th gear I was starting to pull away, then we hit come corners and I slowed down and let him past

that M3 has 400bhp.

so no issues with my car, but would prob not make 414 on a RR

[mark758]

Assuming from what you have said that you are not a B7 owner yet Sims?
I've come from a 300+bhp car weighing 300Kg lighter so I know it has more than 300bhp lol

Few things really....
1. Like PG I've had my car on the same dyno a few weeks apart with 50bhp difference.
2. Unless these cars were putting out over 400 they just wouldnt record the figures they do. You can see punters on youtube doing 12.8 quarter miles and even a mapped car doing 187mph gps.
3. Also have had a similar E92 M3 experience - now let them get on with it
4. People wanting to get away from other cars while they make large unauthorised bank withdrawls keep stealing them - a good endorsement?
5. I keep noticing speedo needle movement never quite believing it

[Terry1948]

As P.G. Says the only way to prove or disprove is to take an engine out and put it on a dyno. Ther are too many variables on a R.R. Its a bit like climate warming. I say enjoy your car and roll on the warmer weather.

[P_G]

Thing is though stumpy67, having been up against E90 M3's, an IS-F and an E39 M5 who were all trying they don't get away from you in an RS4. I doubt a 300ps car could do that?

But would a 420ps car get past them with ease? or are you suggesting none if these make the stated power. I have not seen any threads about this for the E9? M3's or the E39 M5.

Plese note I am here because I like the B7 RS4 concept.

According to the very same r/r operators who rate our cars at 300 or 350 ps, M3's and old M5's make their claimed power on the rollers. Can't say anything about an IS-F as I have not personally heard of one being dynoed.

[Sims]

... or simpler still, do the 3000-8000 rpm in third test and time how long it takes for your car to do that. If around 8 seconds then I'd suggest your car is near the mark.

As you suggested P_G

5 runs, engine temperature at 95, level road.

9.28 seconds, 8.99, 9.05, 9.01, 9.04

What does this imply Sir?

[P_G]

A few further questions for you sims?

Are you a saloon, Avant or cab?
How much fuel did you have on board at the time?
Was it just you or did you have passenger / extra weight on board?
Are you using 95, 98 or 99 RON fuel?
What was the external temperature?
Did you have the accelerator flat to the floor before you hit 3000rpm or hit 3k rpm then nailed it?

[Sims]

According to the very same r/r operators who rate our cars at 300 or 350 ps, M3's and old M5's make their claimed power on the rollers.

And that is my point. Why the discrepancy? Is anyone not curious?