Is this old news? I knew the rs4 was making less power than claimed but is this accurate?
01-26-2008, 09:16 AM
#1
AudiWorld Super User
Thread Starter
Join Date: Jan 2006
Posts: 3,442
Likes: 0
Received 0 Likes
on
0 Posts
Is this old news? I knew the rs4 was making less power than claimed but is this accurate?
<ul><li><a href="http://www.rri.se/popup/performancegraphs.php?ChartsID=769">http://www.rri.se/popup/performancegraphs.php?ChartsID=769</a</li></ul>
01-26-2008, 09:21 AM
#2
AudiWorld Super User
Join Date: Nov 2002
Location: Montreal, Canada
Posts: 18,597
Likes: 0
Received 0 Likes
on
0 Posts
And how exactly is that not the Audi claimed 420 crank HP?...
First of all it should be 414 BHP (not 413).
Given that the <b>WBHP</b> rating on that dyno shows a 328 BWHP figure it seems good enough to me. That's only a 20.6% drivetrian loss with that dyno which is on th low side.
Generally we accept a 25% drivetrain loss for Quattro. This figure changes depending on dyno type so that's why it is basically impossible to compare numbers for any car from dyno to dyno.
Given that the <b>WBHP</b> rating on that dyno shows a 328 BWHP figure it seems good enough to me. That's only a 20.6% drivetrian loss with that dyno which is on th low side.
Generally we accept a 25% drivetrain loss for Quattro. This figure changes depending on dyno type so that's why it is basically impossible to compare numbers for any car from dyno to dyno.
01-26-2008, 12:31 PM
#3
AudiWorld Super User
Join Date: Feb 2001
Posts: 2,552
Likes: 0
Received 0 Likes
on
0 Posts
Something does not makes sense, The A4 2.0TFSI quattro has only a 6% loss when Rs4 has 20%?
if you look at all the other cars they are much closer than the Rs4 is. Why would the RS4 have more drive train loss than other quattro cars?
01-26-2008, 04:24 PM
#6
AudiWorld Super User
Join Date: Nov 2002
Location: Montreal, Canada
Posts: 18,597
Likes: 0
Received 0 Likes
on
0 Posts
There is no way Quattro as only 6% drivetrain loss. Heck the best you can see from ...
A mid engine RWD car or a FWD car is 11-12%.
With the TorSen Quattro you have to work with ~ 25% loss.
As for the A4 2.0T FSI depending on the dyno type the guys have seen any where from 165 WHP to 185 WHP in stock form. There is no way that the claimed 200 HP at the crank Audi advertises is true.
With the TorSen Quattro you have to work with ~ 25% loss.
As for the A4 2.0T FSI depending on the dyno type the guys have seen any where from 165 WHP to 185 WHP in stock form. There is no way that the claimed 200 HP at the crank Audi advertises is true.
01-26-2008, 05:27 PM
#7
Depends on dyno, ambient temps, and how the car was tested. S6 also shows low
as do quite a number of the normally aspirated Audis. This company makes wheel hub dynos, so obviously their system does not favour or at least replicate the conditions used by the factory with their rolling road Maha dynos. Lots of unknowns. And then there is the experience of the operator:
"Incorrect Coast Down - This is a common problem during testing. In order to measure drag
loss during coast down on a manual car, the operator must dip the clutch at the end of the run
to disengage the clutch from the engine. This way, the dyno can measure the power back to
the clutch or flywheel. But what some operators do is to put the car into neutral. This has the
effect of registering lower drag losses as you are only measuring losses back to neutral. This
is a good way of reducing engine power figures when convenient to do so! "
http://www.dyno-tuning.com/dyno-tuning/dynoscience.pdf<ul><li><a href="http://www.turbomagazine.com/tech/0402tur_dyno_tricks_problems/index.html">http://www.turbomagazine.com/tech/0402tur_dyno_tricks_problems/index.html</a</li></ul>
"Incorrect Coast Down - This is a common problem during testing. In order to measure drag
loss during coast down on a manual car, the operator must dip the clutch at the end of the run
to disengage the clutch from the engine. This way, the dyno can measure the power back to
the clutch or flywheel. But what some operators do is to put the car into neutral. This has the
effect of registering lower drag losses as you are only measuring losses back to neutral. This
is a good way of reducing engine power figures when convenient to do so! "
http://www.dyno-tuning.com/dyno-tuning/dynoscience.pdf<ul><li><a href="http://www.turbomagazine.com/tech/0402tur_dyno_tricks_problems/index.html">http://www.turbomagazine.com/tech/0402tur_dyno_tricks_problems/index.html</a</li></ul>
Trending Topics
01-29-2008, 08:30 AM
#10
AudiWorld Super User
Join Date: Apr 2006
Posts: 13,234
Likes: 0
Received 0 Likes
on
0 Posts
FWIW, someone posted a 'side by side' dyno report: IIRC, 331 for the
RS4 and 338 for the R8 (attributed to different intake and exhaust plumbing).
I don't much care...it drives much faster than two tons and 420 hp/317 footie poundage.
I don't much care...it drives much faster than two tons and 420 hp/317 footie poundage.
