RS4 B7 Stated Power claim of 420ps

[RS04EDD]

Can i just add my 2 pence to this?

I used to and still do as a hobbie, fit and calibrate motec ecu's. I have done this from formula fords to engines such as monotune jag v6's.

Firstly, Carbon build up will result in such a tiny power diffrence that no one would notice it. Infact we actually run engines in to build a small layer of carbon on the intake buy retro fitting an egr during run in. You would maybe notice it in a formula where engines where restricted. But in the real world you wouldnt.

Secondly. Anyone stating that the cars arnt producing power and they are basing these fiqures on Rolling Roads need to pipe down. Never has the motor industry used these for power measurement. Power measurement and mapping is always done in a test cell end of. Rolling roads are used to polish a car to take into account bearings with wheels, unsprung weight etc.

I would never and i know some of the best uk engine builders and mappers that would ever!!! use a rolling road for power measurement. They can be used for tuning but even then they should be treated with a pinch of salt.

The worst case and this is why the problems with power readings arise is because four wheel drive RR are still massivly inaccurate.

[Sims]

There is of course something called factory tolerance.

As I understand it, manufacturers are permitted a 10% deviation from the power they claim.

So the best engines would produce 420, but most would only produce only about 380 at birth, and then the fsi problem further degrades this. That would tie up well with the rolling road's are revealing.

[RS04EDD]

Ford are the worst as they work on a 13% correction ratio ive tested duratecs that are meant to be 130ps and turn out to be 110 ish.

[S2tuner]

RS04EDD: the biggest problem with carbon build-up is when it clogs the valves and prevents them from seating correctly, it happens a little bit too much in FSI engines, unfortunately you can't claim that's a good thing, as leakdown is usually below 60% when this happens....

[RS04EDD]

i wasnt aware it caused a seating problem. I would imagine that, this is quite a rare case? the leakdown fiqure is awful. on how many b7's have you seen this?

[SR71]

RS04EDD,

You might want to read this:

http://www.rs246.com/index.php?name=PNp ... ght=carbon

[sonny]

So some one please correct me if im wrong, all FSI engined cars (VW,Porsche) will not make the manufacturers claimed figures.

as much as I'd love to say you're right, unfortunately you aren't. We've just had a V10 R8 on the dyno in France last week, it dynoed 535 crank with a Supersprint exhaust that removes the 2 main cats, but retains the stock precats. On Supersprint's dyno, it had put out 548 PS a few weeks before, but their Maha has some weird correction factors. After remap, it dynoed (on our Cartec dyno) a very consistent 575 to 585 crank PS.

Ok I did not finish the sentence when I submitted it the post . I WAS meant to write that FSI engines loose performance after XX amount of miles due carbon build up. however interesting power figures there from the R8.

What was the mileage of the R8?

[ArthurPE]

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

and the M3 is 300 lbs lighter...

[ArthurPE]

... 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?

how did you time that, the OBC is only 1 digit of precision...
your car has a problem, the other 50 runs average 8 sec flat...
none higher than 8.5, and he ran 8 in another run

let me get this right:
he suggested it at 12:56
you posted at 1:14
and had results by 1:57
???

[ArthurPE]

Can i just add my 2 pence to this?

I used to and still do as a hobbie, fit and calibrate motec ecu's. I have done this from formula fords to engines such as monotune jag v6's.

Firstly, Carbon build up will result in such a tiny power diffrence that no one would notice it. Infact we actually run engines in to build a small layer of carbon on the intake buy retro fitting an egr during run in. You would maybe notice it in a formula where engines where restricted. But in the real world you wouldnt.

Secondly. Anyone stating that the cars arnt producing power and they are basing these fiqures on Rolling Roads need to pipe down. Never has the motor industry used these for power measurement. Power measurement and mapping is always done in a test cell end of. Rolling roads are used to polish a car to take into account bearings with wheels, unsprung weight etc.

I would never and i know some of the best uk engine builders and mappers that would ever!!! use a rolling road for power measurement. They can be used for tuning but even then they should be treated with a pinch of salt.

The worst case and this is why the problems with power readings arise is because four wheel drive RR are still massivly inaccurate.

jeez, someone finally understands the physics...
IF deposits limited air flow (they really don't) all you'ld have to do is crack the throttle a bit more, it is oversized to compensate for air density, filter loading, and yes, deposits

[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?

how did you time that, the OBC is only 1 digit of precision...
your car has a problem, the other 50 runs average 8 sec flat...
none higher than 8.5, and he ran 8 in another run

let me get this right:
he suggested it at 12:56
you posted at 1:14
and had results by 1:57
???

P_G has suggested an alternative method of testing, and I shall endeavour to get that done tomorrow.

stop watch operated by passenger.

I am not far from a road where I can carry out necessary tests, and I have keys to my car whenever I want them

[ArthurPE]

There is of course something called factory tolerance.

As I understand it, manufacturers are permitted a 10% deviation from the power they claim.

So the best engines would produce 420, but most would only produce only about 380 at birth, and then the fsi problem further degrades this. That would tie up well with the rolling road's are revealing.

not true...the tolerance is allowed in 2 levels:
type testing and production variance...total is <5%...+/-, not only minus
with current mfg tolerances, it's less
you can't rate the engine 420 and have it make 380 without having one make 460...
the engine is SAE certified in the US at 420 HP (SAE)

you obviously don't understand statistics...
for them to rate 420, there would have to be as many above, as below for the average to 420...

FSI makes more power (allows higher comp ratio), it does not lose power
the deposits cost no power

[ArthurPE]

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?

how did you time that, the OBC is only 1 digit of precision...
your car has a problem, the other 50 runs average 8 sec flat...
none higher than 8.5, and he ran 8 in another run

let me get this right:
he suggested it at 12:56
you posted at 1:14
and had results by 1:57
???

P_G has suggested an alternative method of testing, and I shall endeavour to get that done tomorrow.

stop watch operated by passenger.

I am not far from a road where I can carry out necessary tests, and I have keys to my car whenever I want them

I call BS...and troll

use the OBC, it will be more accuarte, better view of the tach

[Sims]

type testing and production variance...total is <5%...+/-, not only minus
with current mfg tolerances, it's less
you can't rate the engine 420 and have it make 380 without having one make 460...
the engine is SAE certified in the US at 420 HP (SAE)

you obviously don't understand statistics...
for them to rate 420, there would have to be as many above, as below for the average to 420...

That's not my experience, but my experience is from a couple of decades ago. In those days, BMW M3 engines were rated at 220ps (considered a limit for 2.3litre engine), but most made just over 200ps. I was fortune enough meet the BMW motorsport engineers who explained that some engines were given special treatment to produce the stated ps. NO production engine output 244ps as per your suggestion. You misunderstood what I had said about the 10% variance permitted - it was within 10%, not an average.

To increase power, they were forced to increase cubic capacity to 2.5, and this output 238ps.

Things may have changed, but why are we geting all this debate about RS4 engines?

I am not an engineer, or technically minded.

[Sims]

I call BS...and troll

I shall ignore that comment this time.

use the OBC, it will be more accuarte, better view of the tach

I had pretty accurate timings, a good view of the rev-counter