Audi rates the car with all accessories: steering pump, alternator, water/oil pump, etc., that is law...you can NOT rate the engine with out accessories...
you can not rate the the car without the 'as sold' air intake and/or exhaust system...
it would be hard to do so as most accessories are chain driven on this car...
the only thing to consider is the alternator, steering pump and the AC compressor are not fully loaded...a few HP at most...
to say Audi 'cooked' the numbers is to accuse them of criminal activity...that's slander and/or liable
we are grasping at straws to justify the numbers, both 'sides'
NO one knows the true crank output of the motor
we have seen no correction factors...the ones shown were bogus...they decrease as rev's went up, that's counter intuitive
the graph I posted, with actual MEASURED losses, increase with RPM...for a loss at peak of 25%...so to correct you must mutliply by 33%
so if you make 310 whp, you are making ~ 412 crank
dynos can, and are manipulated for various reasons...
if the car runs ~13 at 107 mph and weighs 4100 lbs loaded, it's making >400 HP...period
My thoughts on Low power, remaps,dynos and carbon
That's what I was confused about.
Most European automakers list their numbers as BHP, but the official definition of BHP is the engine WITHOUT accessories.
Then comes SAE, which is WITH accessories, and then comes drive wheel(s) HP.
Unless you mean British HP, instead of Brake HP, in which case my point is moot :p
I've never heard of it being illegal, at lease not in North America. It's the same as amplifier companies using Peak Wattage (instead of RMS) or diet pill commercial where people lose 60 lbs. None of it is typical results, and I don't see why automakers wouldn't be allowed to do the same.
After all, the engine DOES produce that power number, in one form or another.
Most European automakers list their numbers as BHP, but the official definition of BHP is the engine WITHOUT accessories.
Then comes SAE, which is WITH accessories, and then comes drive wheel(s) HP.
Unless you mean British HP, instead of Brake HP, in which case my point is moot :p
I've never heard of it being illegal, at lease not in North America. It's the same as amplifier companies using Peak Wattage (instead of RMS) or diet pill commercial where people lose 60 lbs. None of it is typical results, and I don't see why automakers wouldn't be allowed to do the same.
After all, the engine DOES produce that power number, in one form or another.
Last edited by Lebult on Sat May 16, 2009 6:58 pm, edited 1 time in total.
both test with accessories...the only difference is minor...basically a cf...Lebult wrote:That's what I was confused about.
Most European automakers list their numbers as BHP, but the official definition of BHP is the engine WITHOUT accessories.
Then comes SAE, which is WITH accessories, and then comes drive wheel(s) HP.
Unless you mean British HP, instead of Brake HP, in which case my point is moot :p
0.986 HP (SAE) = 1 PS or DIN/International HP
420 x 0.986 = 414
http://en.wikipedia.org/wiki/Horsepower
The German Way: DIN Horsepower Ratings
Since we've been talking more about European cars this year, we have been making frequent references to "DIN" power ratings. We wanted to be sure everybody is clear on what that means.
DIN is short for Deutsche Industrienorm (German industry standard), a standard issued by the German national institute for standardization. That institute, known between 1926 and 1975 as Deutsche Normenausschuss (DNA), is now called Deutsches Institut für Normung, also abbreviated DIN. Among other things, the agency sets standards for how the horsepower and torque of automobile engines should be measured -- Deutsche Industrienorm 70020.
As you might imagine, the standards of DIN 70020 are specific, and very strict. Unlike the SAE gross standards used in the U.S. and Great Britain for many years, it requires power to be measured with standard intake, exhaust, and accessory systems in place. DIN horsepower ratings, therefore, are comparable to the modern SAE net rating system, although they are usually reported in Pferdestärke (literally, "horse strength," but generally referring to metric horsepower), rather than mechanical horsepower. One mechanical horsepower is 746 watts, whereas one metric horsepower is 736 watts; therefore, 1 PS equals 0.986 horsepower. Because of that, and because DIN horsepower ratings are calculated with the engine in "as-installed" condition, they are always lower than gross ratings. (The peak engine speeds for DIN power and torque ratings are often lower, as well, reflecting the effects that mufflers, air cleaners, and accessories have on the engine's power curve.)
Until the early 1970s, it was not uncommon for cars sold worldwide to have two power ratings, one DIN, one gross, largely as a concession to the salespeople. A Porsche 356 Super 90 engine, for example, was rated 90 hp DIN, but 102 hp SAE. Adding to the fun was the fact that, as we've previously discussed, SAE gross numbers were often dictated more by the marketing staff than the engineering department, and sometimes bore little relationship to actual output. This did NOT mean that the U.S. or British engines were more powerful than their European counterparts, simply that their ratings were figured differently.
So, before you write us to complain that we have maligned your favorite car by saying it had less power than advertised, please consider the source, and whether that source was quoting SAE gross, SAE net, or DIN figures.
Since we've been talking more about European cars this year, we have been making frequent references to "DIN" power ratings. We wanted to be sure everybody is clear on what that means.
DIN is short for Deutsche Industrienorm (German industry standard), a standard issued by the German national institute for standardization. That institute, known between 1926 and 1975 as Deutsche Normenausschuss (DNA), is now called Deutsches Institut für Normung, also abbreviated DIN. Among other things, the agency sets standards for how the horsepower and torque of automobile engines should be measured -- Deutsche Industrienorm 70020.
As you might imagine, the standards of DIN 70020 are specific, and very strict. Unlike the SAE gross standards used in the U.S. and Great Britain for many years, it requires power to be measured with standard intake, exhaust, and accessory systems in place. DIN horsepower ratings, therefore, are comparable to the modern SAE net rating system, although they are usually reported in Pferdestärke (literally, "horse strength," but generally referring to metric horsepower), rather than mechanical horsepower. One mechanical horsepower is 746 watts, whereas one metric horsepower is 736 watts; therefore, 1 PS equals 0.986 horsepower. Because of that, and because DIN horsepower ratings are calculated with the engine in "as-installed" condition, they are always lower than gross ratings. (The peak engine speeds for DIN power and torque ratings are often lower, as well, reflecting the effects that mufflers, air cleaners, and accessories have on the engine's power curve.)
Until the early 1970s, it was not uncommon for cars sold worldwide to have two power ratings, one DIN, one gross, largely as a concession to the salespeople. A Porsche 356 Super 90 engine, for example, was rated 90 hp DIN, but 102 hp SAE. Adding to the fun was the fact that, as we've previously discussed, SAE gross numbers were often dictated more by the marketing staff than the engineering department, and sometimes bore little relationship to actual output. This did NOT mean that the U.S. or British engines were more powerful than their European counterparts, simply that their ratings were figured differently.
So, before you write us to complain that we have maligned your favorite car by saying it had less power than advertised, please consider the source, and whether that source was quoting SAE gross, SAE net, or DIN figures.
Great write up Andy. Although mine does feel fast-ish on the road, it certainly doesn't have the extra kick at 5500rpm, as I've mentioned before, and if you look at my plots, when compared to Sonny's, mine is down right from the start. Now I am not saying that the carbon build up is causing it, but it doesn't take a scientist to work out its not doing the airflow any good, and I am looking forward to seeing mine when I make audi take the manifold off. And once that has been replaced/cleaned, at least that is one box they can tick as sorted and move onto the next. What is the cause of my all round low power, go knows, but I'm sure Audi will get to the bottom of it, and if it takes them 3 weeks then so be it.
Funnily enough I was saying to Sonny yesterday that my throttle pedal feels vague at times, and the plots show that, it just doesn't seem very responsive.
And then there are other days when the cars seems to run like rocket.....
Funnily enough I was saying to Sonny yesterday that my throttle pedal feels vague at times, and the plots show that, it just doesn't seem very responsive.
And then there are other days when the cars seems to run like rocket.....
Last edited by Oli on Sat May 16, 2009 10:09 pm, edited 1 time in total.
Oil,
that may be a clue to what is wrong with your car. There is a procedure to reset the throttle and pedal.
It might be worthwhile speaking to the guy you bought the car from and try and get him to cough any history to help you.
An interesting point, it just shows, that say I had looked at the car with you, I probably would have noted the performance problem.
that may be a clue to what is wrong with your car. There is a procedure to reset the throttle and pedal.
It might be worthwhile speaking to the guy you bought the car from and try and get him to cough any history to help you.
An interesting point, it just shows, that say I had looked at the car with you, I probably would have noted the performance problem.
RS4 Avant - Sold Aug 2009
Cheers Andy
When I first got it, it definately had the second surge of power @5500rpm. However you know what its like, you get used to a car and its perfromance, plus I mostly drive it at weekends as my wife drives it 80% of the time, and after driving various hire cars from my fleet, most sports cars will feel fast!
When I first got it, it definately had the second surge of power @5500rpm. However you know what its like, you get used to a car and its perfromance, plus I mostly drive it at weekends as my wife drives it 80% of the time, and after driving various hire cars from my fleet, most sports cars will feel fast!
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