RS4 interesting tidbits

DIY/TECH/INFORMATIVE
#1

Post up something interesting about the RS4 that may be unique to it, or may differentiate it a it from the competition or from it’s siblings, the A4/S4. Doesn’t have to be technical…just something interesting you’ve noticed.

I’ll start


Hood - The RS4 hood is made of aluminium and weighs only 27 lbs.
It’s very light compared to normal hoods. For this reason, I can’t see the point in getting a carbon fibre hood on an RS4, but I guess some people do. Here are the stats as I know them…

B7 S4/A4 hood - 53 lbs
B7 RS4 hood - 27 lbs
Dual sided CF hood with pins - ~15-20 lbs

As you can see, the RS4 hood is already VERY light. A really nice little weight shave by Audi.

#2

The front quarter panels are also Aluminum as well. That’s impressive about the hood, I wonder what the price difference would be between a CF and AL hood.

RS4’s only came in Manual, funny how the RS5 only comes in Auto (DSG)

#3

That is funny about the manual vs auto. I think those front fenders weigh around 6lbs each…not certain though. Someone was talking about CF front fenders and I remember thinking this will be an interesting spend lol.

Here’s one about the RS4 that confuses the shit out of me. Compared to the b7 S4…the RS4 has an aluminium hood (-25lbs), aluminium fenders (-25 lbs), no spare at all (-50 lbs) for a total of 100 lbs weight shaved vs the s4. Despite all of this, the RS4 is 100 lbs heavier than the B7 S4. Even though the rs4 uses 19x9 wheels vs the 18x8 S4 wheels, they each weigh 50lbs.

I can’t figure that out. Where is the pudge? Same interior. Same sized engine etc. Anyone? Where is that 200 lbs hiding?

#4

Well this is what I can think of:

  • Wide Body: More material
  • Wider axles: More material
  • Different gearbox: could be heavier with stronger gears.
  • Not quite the same motor it is FSI, so it could be slightly heavier with fueling and such
  • sound system and nav, this was an option on the S4’s so the weight would not include this.

They all might be a few pounds here and there but it will add up.

#5

brakes and drc are gonna add some weight

#6

Prior two posts plus the other little things probably add up: 2nd ECU, additional wiring to and from, larger fluid capacity (oil pan), fluid in drc, I’m almost positive our engine weighs more, I think we have beefier suspension bits (sways, control arms) etc…

#7

Its just like the CLK63 Black, it has a striped interior but then ways slightly more than the standard CLK63. This is becuase it has a beefed up drive train and suspension bits, hence why they had to make some lighter parts so it doesn’t look like a fatty boombalada next the standard car.

#8

I was comparing to my 07 s4 which weighed right on 3850…and had the rs4 sways, the navigation and fully loaded interior with blutetooth, sat radio etc. All the tricks.

I guess that other stuff would add up real quick though.

Next little known fact - the rs4 can’t do an oil change with an extractor because it has an oil pan that is divided into a bunch of sections. This is because of the anticipated high cornering Gs which would see oil slosh about so badly potentially starving particular parts of the engine. There are weird little gates and dividers to make sure oil stays put. I’m sure I’m butchering the tech behind it. Its in the self study guide.

Interestingly the S4 (b6/7 and b8) don’t have this feature, so all the road-racing superstars should beware!

#9

I think a decent resource on where the weight is coming from would be mickf, he has a list posted with the weight of all the stock shit he’s removed.

#10

Here’s a tidbit, RS4s show oil temp in the DIS.

#11

true that’s a good one. Mine took forever to get to temp today. It was 7 degrees fahrenheit here this morning. It’s interesting to watch the relationship between the coolant temp and the oil temp. Oil lags a bit as you’d expect as you warm up. The DIS shows oil temp but shows “MAX 7000/min” when its cold until you get to I think 51 Celsius (around 120 Fahrenheit). On my 15 minute commute to work, it only got off the 7000 RPM limit message just before I arrived in the office…and my car is parked in a garage attached to the house where it is usually about 20 degrees fahrenheit warmer than outside. Crazy.

#12

Yeah the MAX 7,000 RPM msg doesn’t go away until the oil reaches 122F. I actually won’t turn my car off until the oil temp reached 170 ocne I start it. For example, the deli I often buy my breakfast from is 2 miles away from my house. In the winter my oil doesn’t even reach 122 by the time I get there. I take the LONG way there just to ensure I reach operating temps, lol. My wife hates it but it’s what I like to do. I know, OCD.

Tidbit: Our splash guard/engine cover (under the car) has two ducts that funnel cool air to our front rotors.

#13

S-button and exhaust flaps.

#14

come on karsty…explain it! No free rides on AR :slight_smile:

#15

Ok ok. I guess I just took it for granted that everyone knows this.

S-button on the dash that when engaged tweaks the throttle response so the engine is a bit more responsive, as well as opens up flaps in the mufflers via a vacuum source to inhance the V8 rumble. When the S-button is not engaged, the flaps are closed and there is only one exhaust exit path per muffler. When it’s on, the flaps open and there are two exhaust exit paths per muffler.

:slight_smile:

#16

Nice! I recently learned that in sport mode, the flaps are not actually always open which is interesting.

With sport mode engaged, in neutral, or in 1st, 2nd and 3rd gears, they are open from 0-1000 rpm (idle) but then close from 1000 to 4000 rpm…then they open from 4000 to 8250. In 4th, 5th, 6th, they’re always open.

Another interesting fact is that in 1st, 2nd and 3rd gears, THROTTLE RESPONSE is limited greatly up until about 5500 RPM (limited to 52%). You can see this on my log below. I’d like to know the rationale behind this, and closing the flaps in those same gears for pretty much that same RPM range. I’d also like to see the results of pulls between two cars: 1 fully stock, and 1 with throttle NOT restricted in 1-2-3 and the flaps fully open for all of 1-2-3. I bet even though both cars were pretty much stock, the unrestricted car would pull pretty good. It would be even funnier to compare the dyno plot for both cars to see what we’re missing down low in 1-2-3.

http://audirevolution.net/addons/albums/images/729968961.jpg

http://audirevolution.net/addons/albums/images/729968961.jpg

#17

I hate you guys…:slight_smile:

#18

75% of RS4 owners have ego’s bigger than their fender flares.

#19

Impossible. Nothing is bigger than RS4 fender flares***.

*** MB Black Series excepted

#20

Found this interesting

[QUOTE]The RS4 naturally aspirated V8 engine was design by Wolfgang Hatz, same man who was responsible for the iconic four-pot motor from the original M3, as well as some BMW and Ferrari F1 powerplants.
The piston speed of the RS4 engine (25.5 metres per second) is nearly as fast as the F1 engine. The very same engine meets Euro 4 emissions standards, has 19,000-mile service intervals, just like any other Audi, and should (according to Hatz) go 155,000 miles before any major maintenance is required.
[/quote]