not scientific, for fun only

[ArthurPE]

ran some dynolicious (iPhone data app) runs (6 runs over 3 days, same spot, ~50F, alt 1100' ASL, high humid, slight incline)
calibrated it right before use each day, made a styrofoam mount for the cup holder, made sure it was plumb
some say very accurate, some say a bit high (reads slower than actual, perhaps a 0.1 or so to 60 mph), but fine for order of magnitude
car has 75k miles, 3/4 tank of gas, 30k miles since only valve clean, last year only short trips, running rich, never really gets warm, so I'm sure the valves are fouled
I turned the roll-out down to 8" from 12 and the g trigger to 0.06 from 0.08

avg of 6 runs
0-60 5.12
sounds slow but 1100 ASL and slight incline
also my 0-20 avg 1.54 (most mags did a bit less than 1 sec or so, I launched soft at 2500 and eased into it, no high rev drop)
R&T 0.8, R&T comparison test 0.7, sportauto 1.4 to 25 mph, C&D 1.7 to 30
R&T had a 0-10 of 0.2 in both tests, mine wa 0.95 (my 0-60' avg 2.44, way slow)
all my time was lost in the launch, 10-60 equaled all the mag tests, or bettered them
mine 4.17
R&T 4.3

using the following
wt of 4150 (probably high, my car has no sunroof or nav)
driveline loss 20% (most healthy engines, cleaned or not do 320-330 at the wheels)
408 HP estimate from the runs (I know, a coincidence, but still close) when alt is factored in

this indicates to me that my car is doing just fine
going to do some 1/4 mile runs when I get a chance

[54Kab]

- interesting stuff Arthur, thanks for posting. Is there any 'proof' that these cars get quicker once they're properly run-in -c60-70k miles ?? That would potentially off-set any reduction due to carbon build-up etc ?

- What fuel were you using ? Presume that could vary the results too..?

[ArthurPE]

- interesting stuff Arthur, thanks for posting. Is there any 'proof' that these cars get quicker once they're properly run-in -c60-70k miles ?? That would potentially off-set any reduction due to carbon build-up etc ?

- What fuel were you using ? Presume that could vary the results too..?

a US magazine Autoweek does a test when new and a follow-up at 40k miles for many different cars (don't think they did the RS4)
many improve at 40k after the engine is broken in
machinists have told me that if maintained and broken in properly BMW/Auid/etc engines are still within factory mfg tolerances at 20k miles, meaning they aren't even really broken in!

I use Shell 93 (basically your 98 or so)

in general, the car appears to be as fast as it was when new, which is impressive when you consider it's done 75k miles

[adsgreen]

Engines wear in quicker but even still I'd say Arthur is about right with the 20k mark - it'll vary on how those 20k miles accrued but not bad rule of thumb.
Transimssions on the other hand I've found can take two or three times as long. No direct knowledge of the RS4's but wouldn't be surprised to find out that things don't get properly sorted until 50k miles all in.

[ArthurPE]

did some more runs (45F, low humid, full tank, level, 1100' ASL)
all 5 runs done in 15 minutes or so on the same stretch of road, two dynolicious, three 3k-8k rpm using obc timer

3-8k
8.1
8.2
8.2
very careful to start the timer as the needle approaches 3k and stop after it sweeps through
mags are getting 8 or so USING THE GEARS for the same speed range
my 0-60' are bad, avg 2.5/32 mph, lauch 2500 +/- and don't want to abuse the drive train

dynolicious
run 1
0-10 0.83
0-20 1.56 (losing all the time at the launch, most mags are doing ~0.8 sec to 20)
0-60 5.11
0-100 11.2 (mags range 10.7 to 11.2, fumbled the 3-4 shift a bit)
20-100 9.64 (mags are ~ 10 sec)
1/4 13.35/110
421 HP

run 2
1.15
1.65
5.13 (my 0-60 times are very consistent, +/- 0.1 or so)
10.67
9.02
13.43/101.6 (I let off at the 3-4 shift ~96 mph)
430 HP

I can't convince there is an issue with HP rating or deposits (30k since cleaned)

edit: sport off, traction on/enabled, all season tires

[sakimano]

I have launched my car plenty of times at about 3400-3800 Arthur... The clutch is stout. Just in case you want to give it a go. It will be fine. Just et it cool between launches.

My best 60 foot time is 1.82 with another dozen 1.83. That's at a dragstrip. If you're 2.5 that's going to make it tough to compare. Generally 1 tenth of 60 foot equals 1 tenth of 1/4 mile et on an awd audi. But when you are at 2.5 it's a bit too far out.

Fun little app that. Lots of people enjoy it. Good idea on the styrofoam cup. Lots of people mention that is the hardest part (getting it mounted properly)

You should also change the rollout to 1 foot

[Dom81]

edit: sport off, traction on/enabled, all season tires

Why sport off? I'd have though all tests were done with it on?

[Mr V10]

Title should read 'Completely scientific, and no fun at all'. This thread was the opposite of what the title suggests.

[ArthurPE]

edit: sport off, traction on/enabled, all season tires

Why sport off? I'd have though all tests were done with it on?

it adds no power and I like the longer throttle throw with it off, I can modualte it better

as far as the launch delta I'm figuring it costs 3-4 tenths or so, but my 20-100 splits are as good as, or better, than all the magazine tests I have
even the 5.1 0-60 is good for me, considering how much I lose in the first 10 mph, and some more 10-20...
I'm convinced the car is meeting, or exceeding, spec

[adsgreen]

edit: sport off, traction on/enabled, all season tires

Why sport off? I'd have though all tests were done with it on?

Doesn't do anything power or performance wise so comes down to driver preference.

[sonny]

Sounds about right that, good figures.

For those that have the dual map with sports mode im sure this will make a difference to pedal sensitivity enabling driver to achieve the 3k mark quicker. Otherwise car will be using momentum, again something that I have not proven so may be wrong. Talking of which I should really do a updated 3k-8k run.

( I should know the answer) But I do remember reading that there was a power loss with valves open, due to lack of back pressure, is this something that has been proven wrong?

[sar]

( I should know the answer) But I do remember reading that there was a power loss with valves open, due to lack of back pressure, is this something that has been proven wrong?

i very much doubt it, this would kind of negate all free flowing after market exhausts.
how could this have even been measured in the first place?.

[adsgreen]

( I should know the answer) But I do remember reading that there was a power loss with valves open, due to lack of back pressure, is this something that has been proven wrong?

i very much doubt it, this would kind of negate all free flowing after market exhausts.
how could this have even been measured in the first place?.

Slight thread drift but yes you right in that free flowing isn't always what you want however 'back pressure' is misunderstood.
The ecu and valve timing is setup based on OEM parts and certain assumptions are made. One of these is the exhaust characteristics and as such the timing, overlap and the parameters are set such as to maximise the scavenging effect of the exhaust. If you just change the exhaust then these assumptions are wrong and the benefit you get of a more free flowing exhaust is completely lost (and then some) by miss-matched settings.
This is why you do actually suffer a measurable (if slight) power loss if you just bolt on a miltek. However, remap things to suit the new exhaust and then you do generally get a net gain.

[sonny]

( I should know the answer) But I do remember reading that there was a power loss with valves open, due to lack of back pressure, is this something that has been proven wrong?

i very much doubt it, this would kind of negate all free flowing after market exhausts.
how could this have even been measured in the first place?.

As Ads says. The remap will "iron" out all the imperfection so to speak. I have tried to do a search but cant seem to find the topic. irrc it was around 5bhp loss with valves open on a un-mapped car, however the throttle map in sports, made it feel progressively fast. Again this is only from what I can remember from a old thread. Maybe few of the tuners can confirm.

[sakimano]

( I should know the answer) But I do remember reading that there was a power loss with valves open, due to lack of back pressure, is this something that has been proven wrong?

Myth. I have tested the car with valves open and closed and it's identical. Lots of third gear runs from 2k-8k logged on vagcom etc.

There are enough restrictions in the stock exhaust that the valve isn't going to be so much of a game changer.

Closing of the exhaust valves between 1000-3500 rpms in gears 1-2-3 in sport mode is to limit drone.