RS4 power test

[Fab]

I just red on a swiss forum that the well known tuner Sportec took 2-3 RS4 V8 on the dyno. None of the 3 cars had more than 390 hp output :doh: which is quiet a big difference compared to 420hp.

One explanantion was to say that the within the first cars released some engine problems/ ecu prog. took place and that quattro GMBH is aware of it and has/will correct that.

What do you guys think ? Considering that Sportec is one of the best tuner around ? True or false ?

This sounds worrying.

[QuattroFun]

True if they have dynoed the cars - but at least in Audi V8's case, the results are sensitive to how fresh the engine is and I have no idea how they have dealt with/corrected for transmission loss, which is usually some 10%. Let us hope Quattro fixes the engines if there is some problem. But at least the engine in the test car in the newest AMS cannot have been that weak if it outdid C55 and Audi's own sprint claims by the margin it did...

:confused:

[Audihead]

30 ponies isn't bad, that's just @ right for the driveline loss w/Quattro. I believe you can lose any where between 10 and 30% depending on what engine and tranny combo you have.:revs: :rs4addict

[AndyBG]

That is becoming common case today, i can't remeber any recent test that didn't show less power than official spec.

I HOPE that Audi will fix it, it's very sad if they leave it that way.

[tailpipe]

Fab,

Your post is probably the last comment Audi wanted to see posted about the RS4. As you probably know, we were told that the reason for the delay of the RS4 was that they had experienced problems with the new engine during testing. In particular, at high revs, the cylinder head block reached such a high temperature that it reportedly started to melt.

We've heard since that Audi has "fixed" the problem. While part of the solution included a revised cylinder head design and extra cooling, I suspect that limiting top revs and power may have indeed been part of the final package to ensure reliability. Remember the problems BMW had getting 507 bhp out of the 5.0 litre V-10? It's one reason why you have a standard setting of 400 bhp and a sport button - less strain on engine - instead of 507 bhp on tap all the time. (The other reason is fuel consumption.)

Insiders elsewhere report that Audi has fixed the earlier overheating issues. Given the need to get this car to market yesterday, the fix may only be an interim measure while the engineering team develop a better technical solution.

Whatever is going on, Audi is hoping that by saying nothing the problem will go away. It wouldn't be the first car launched with power below manufacturer's claims. I think 30 bhp is significant. After all, the BMW M3 CSL honly has 17 bhp more horsepower than the standard model (360 bhp versus 343 bhp) and this makes a big difference.

[Erik]

I have visited Sportec. http://www.sportec.ch/

I like them. A tidy place, swiss preciscion.

However as far as I know their dyno is a rolling road, which means that any readout is affected by drive line loss etc.

I know a German Porsche tuner who took the new Cayman to the dyno (real engine dyno). It usually has around 285 hp, not 295 hp. And the new 997 Carrera is not always as strong as marketed either.

According to MTM, info I got from my visit, the first old RS4 V6 didn't have 380 hp either, but rather 20-30 hp less if I remember correct. I know there were issues with the old M5 E39s as well.

"Industry standard" it seems. :nono: :vgrumpy:

(edited hp n#)

[Benman]

Originally posted by Erik
I have visited Sportec. http://www.sportec.ch/

I like them. A tidy place, swiss preciscion.

I know a German Porsche tuner who took the new Cayman to the dyno (real engine dyno). It usually has around 385 hp, not 395 hp. And the new 997 Carrera is not always as strong as marketed either.



"Industry standard" it seems. :nono: :vgrumpy:

Cayman has 295, no?

Industry standard needs to upgraded. Less hp than claimed is crap. That quoted hp is the hp the least powerfull car should make, not the most. If Audi says the car makes 420hp, then all the cars should make at least 420. Underachieving is not cool...:nono: :doh:

Ben:addict:

[jmk]

It was not an engine dyno, but a chassis dyno. The RS4 does not and should not make 420 hp at the wheels. This in no way suggests that the car is not as advertised. 390 plus wheel horsepower is amazing btw....:rs4kiss:

[CarbonFibre]

Originally posted by jmk
It was not an engine dyno, but a chassis dyno. The RS4 does not and should not make 420 hp at the wheels. This in no way suggests that the car is not as advertised. 390 plus wheel horsepower is amazing btw....:rs4kiss:
I'm going to go ahead and assume Sportec aren't a bunch of idiots and know the difference between flywheel horsepower and wheel horsepower. I'm guessing that by the nature of the post, someone made their own ignorant assumptions given some results they saw on some forum. Anyway, I think the wheel vs. engine horsepower issue is probably the problem here, but not due to Sportec themselves but someone's incorrect interpretation. It's difficult to say with such limited information.

PS: 390 seems really high for wheel horsepower, so it's possible that there really is an issue with the engines and the quotes of 390 are engine horsepower after a correction factor was applied to the dyno results.

[Erik]

Originally posted by CarbonFibre
PS: 390 seems really high for wheel horsepower, so it's possible that there really is an issue with the engines and the quotes of 390 are engine horsepower after a correction factor was applied to the dyno results.

This is my guess as well. That's how it was done at MTM when I dynoed my A6 2.7.

(edited the Cayman hp N#s to more realistic figures)

[buyalemon]

correct me if I'm wrong ...but E39 M5 produced 367 hp on the wheels 33/400=8,25% loss

RS4: 390? 30/420=7,1% loss ...that's bloody brilliant :revs: ...remember it has quattro and many people allways talks about the great drivetrain in M-cars!

[CarbonFibre]

RS4: 390? 30/420=7,1% loss ...that's bloody brilliant :revs: ...remember it has quattro and many people allways talks about the great drivetrain in M-cars! [/B]
Which is why I'm skeptical. Quattro usually has at least 20% loss in what I've heard and sometimes even more than 30%. Maybe this Torsen 3 is better than I know.

[QuattroFun]

RS4 and S4 are separate cars. Still, dynos at wheel for the latter I have seen range from 270 to 280 bhp versus quoted 344bhp with a transmission loss of some 20%. Hence, without knowing, I am also inclined to believe that the 390bhp figures account for some ordinary template loss adjustment of the on the wheel number from which it apparently is measured from. 390bhp at the wheels would be great - but too good to be true I suppose...

[Fab]

Good analysis guys. I learned new interesting thinks with the above. And this is pretty reasuring about the beast power :revs:

Thanks a lot

Fab

[Audihead]

I lost a bunch of HP when I got my car Dyno'd. I have the '04 S4 w/ the slushbox. Hp went from 340 at the crank down to @ 260 at the wheels. It sucks, I will try never to get a slushy trans again.
:doh:

[Benman]

Originally posted by Audihead
It sucks, I will try never to get a slushy trans again.
:doh:
At least not in a Hi Po RS 4/6.

But works great in a Q7 kinda car.:p

Ben:addict:

[Spada]

Although it's not a massive loss, this really annoys me. There's no way that figure is power @ the wheels. Why is it ok to sell cars that have less hp than quoted!? Benamn I agree, if a car company says a car has "xyz" bhp, then all the cars should have that much. Everyone who paid for "xyz" bhp should get it. THAT should be the industry standard. The delay has cost me thousands in depreciation on my b6 s4, and Audi have used that time to detune my new car! yay!!

If Audi has really made the rs4 with only 390hp I really do despair. The new M3 is going to embarrass it as per usual. Oh well, as long as it performs and all the other car companies are lying too i'll just pretend I never saw this thread lol. I guess as long as i can feel a big difference I don't mind - If my b6 is only making 240 at the wheels and I upgrade to 300, thats an improvement isnt it! What would really piss me off though is if later cars end up with more hp. If what you say is true tailpipe, and after all this time Audi is just gonna sell those who got in line first some detuned cars because they can't keep us waiting any longer, that is just not fair. We should be able to take our cars back to be re-tuned!

[buyalemon]

I really agree with you ..don't know much about U.S "buying laws" ...in Sweden it says "the product shoud in terms of performance, quality etc match what is being said in the marketing"

I don't think the problem is as easy as "re-tune" the car and abrakadabra 60 bhp more ...but why should you pay the price of 340 bhp and get 240? a big shame in my opinion ...is it only the cars with automatic gb?

Audi has been critisised in Swdeish press ...the automatic gb didn't even change gears at the maxrev ...this makes it impossible to reach the bhp-effect even if it would have had the effect. Noooot goood Audi ...really not good!

[skratch]

Originally posted by tailpipe
Fab,

Your post is probably the last comment Audi wanted to see posted about the RS4. As you probably know, we were told that the reason for the delay of the RS4 was that they had experienced problems with the new engine during testing. In particular, at high revs, the cylinder head block reached such a high temperature that it reportedly started to melt.

We've heard since that Audi has "fixed" the problem. While part of the solution included a revised cylinder head design and extra cooling, I suspect that limiting top revs and power may have indeed been part of the final package to ensure reliability. Remember the problems BMW had getting 507 bhp out of the 5.0 litre V-10? It's one reason why you have a standard setting of 400 bhp and a sport button - less strain on engine - instead of 507 bhp on tap all the time. (The other reason is fuel consumption.)

Insiders elsewhere report that Audi has fixed the earlier overheating issues. Given the need to get this car to market yesterday, the fix may only be an interim measure while the engineering team develop a better technical solution.

Whatever is going on, Audi is hoping that by saying nothing the problem will go away. It wouldn't be the first car launched with power below manufacturer's claims. I think 30 bhp is significant. After all, the BMW M3 CSL honly has 17 bhp more horsepower than the standard model (360 bhp versus 343 bhp) and this makes a big difference.

the m3 is high strung to begine with.The csl is making about 113 hp/L that 17bhp increase is huge when the car is already making over 100 hp/L

they had to use a race version ecu and air flow meter delete.That cars adjusts itself on the fly threw the ecu.There is no mass/air/hfm meter on it.

the alpha n ecu is 5 times more powerfull than the standard ecu.

and where have read about the m5 engine needing to default to 400 hp because of reliability?

I have read that this engine was spun to over 10,000 rpms on the ring during testing and had it up to 600 hp.

Id like to read up on the problems you metioned about it tho.Its the first iv heard of them using the 400 hp mode because the engine cant handle it.

hamann has a kit for the new m5 up to 603 hp with headers,chip,and cats

so it does sound like bmw was right about testing this engine up to 600 hp

here is a link to that m5 here (http://www.supercars.net/cars/3299.html)

[CarbonFibre]

Originally posted by skratch
hamann has a kit for the new m5 up to 603 hp with headers,chip,and cats

so it does sound like bmw was right about testing this engine up to 600 hp

here is a link to that m5 here (http://www.supercars.net/cars/3299.html) [/B]
I'd still like to see the dyno plots on that one.

[Speedou]

Well, I have seen automatic S4 0-100 at 6.8s. It's not too good for 340hp :nono: I can't understand why Audi loose so much power with auto trans.

[Spada]

Well I went and saw my car today and one look at it, and all is forgiven. All the performance figures and reviews i've seen so far suggest it's very fast, so I'm not bothered. I wonder how far it can be tuned? :mech:

[skratch]

Originally posted by CarbonFibre
I'd still like to see the dyno plots on that one.

same here,120 hp/l is something bmw should have no problems getting out of this engine.

I mean its torque peak is at 6100 stock

just emagine shifting it over to 7000 with a chip headers and race cats

should be able to come close to those figures.