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Yep, mine's a Cab. Yeah not sure if it's meant to be normal, I expect the timing to be up closer to 30 degrees at those intake and air temps (Audi agree). It didn't have that surge at 5500 when I did this test either. When I gave the results to Audi (back in May) they said it's a problem.

Long story short, they ran some of there own tests, and were scratching their heads trying to figure it out. They suggested Injectors (not they they were 100% but wanted to try something). So when they lifted the manifold last week this is what they found



This is after 5000km. So now Audi don't think it's the injectors, and wondering if the engine has too much blow-by (the manifold was full of oil). While waiting for the injectors (two days before they arrived) I got a engine light related to intake runner flaps. I think the amount of oil in the manifold was making them stick? So, now Audi are looking to take some other more serious steps. The thought was that timing is being pulled back due to excess oil entering the combustion chamber (maybe Arthur you are right, once the carbon builds up to a point the oil/carbon can't get much bigger so it makes it's way into the chamber, thus causing timing <beep>??)

PS: I think I said this before, but when removing the manifold be very careful of the plastic intake runner flap arms. Unfortunately for Audi they broke one, so it's a new manifold again (at the dealers cost, which kinda sucks as the dealer is great!)

are you saing the 8.25 sec was run with those deposits?
if so, your car is heavier, yet ran better than the baseline (close to a saloon using all gears) which would reaffirm my belief that deposits cause very little, if any, power loss...

what temp were the runs made?
what fuel octane?

there is no fixed value for timing, it varies based on input parameters...
it can be reset by the knock sensor, which can be logged during the run
otherwise it just follows a mapbased on temp, rpm, load, throttle position, etc.
if you look at your numbers it is ~27 until 7700 rpm!
then backs off, after HP peak, imo it's the soft limiter cutting power before fuel cut-off...
look at the fuel mixture (lambda) it's right at setpoint all the way to 7800+ (0.85 vs 0.85), then the setpoint increase towards 1, as the timing drops...it looks like everything is working perfectly...in fact it follows setpoint all the way from 2000 up, as the setpoint changes, the actual follows...amazing...the precision and speed of control response is amazing...

at 14.84 actual = setpoint = 0.9
at 15.57 setpoint has changed to 0.85, and the actual has followed it perfectly...less than 1 sec! a thing of beauty...

Intake air temps were between 30-35 degrees C (this is on another log done at the same time). Fuel was 98 RON.

I agree AFR looks good too. Yep, and I understand timing isn't a fixed value. I'd expect the "map" to have timing set between 30-35 degrees if you could actually see it. What actually happens, is once timing is pulled into the low 20's the car doesn't have the kick at 5500rpm. This is what was happening to me during the day (the run was done at night in the cold air, about 18'C outside so it was ok). This log was done just as the problems were coming back. In this log, if I remember correcty, the kick was there, only just (in second gear, but this log was 3rd gear).

When I log it now (well last week as the car is in the shop) timing was around 23 degrees. That's with outside air temps around 12-14 degrees C. It got worse very quickly (over a period of about 4-8 weeks or 5000kms)

So anyway, with the timing being pulled back and given my car is heavier, I'd expect a "good" sedan to be 8 seconds (doing the same test I did, using VAGCOM). One doing 8.5 seconds could probably be quicker, but we might leave that for another day

I'll be keen to do the test again once the car is fixed for good.

8.5 sec is the std at ~70F as measured by numerous magazine and dyno runs...
8 flat is a car using ALL gears for the same speed range (36 to 96 mph)
again, from >5 different magazine tests...it is very consisitent, within +/- 0.1 sec...

8.25 for a heavier car in that temp ~65F, is better than spec...

99 octane is not available?
1 more point may have given you another degree or 2...
I've seen the stock map...it max's ~30 at ~7700 then backs off a few degrees, pretty much like yours, just offset 3 deg...

honestly, I can't see any issues with the data or times...

the cab wieghs ~300 lbs more (3900+ vs 4200+)
scale weighed by edmunds
that is a lot...I would expect the cab to run 8.8 to 8.9 vs 8.5

2manytoys wrote:Intake air temps were between 30-35 degrees C (this is on another log done at the same time). Fuel was 98 RON.

I agree AFR looks good too. Yep, and I understand timing isn't a fixed value. I'd expect the "map" to have timing set between 30-35 degrees if you could actually see it. What actually happens, is once timing is pulled into the low 20's the car doesn't have the kick at 5500rpm. This is what was happening to me during the day (the run was done at night in the cold air, about 18'C outside so it was ok). This log was done just as the problems were coming back. In this log, if I remember correcty, the kick was there, only just (in second gear, but this log was 3rd gear).

When I log it now (well last week as the car is in the shop) timing was around 23 degrees. That's with outside air temps around 12-14 degrees C. It got worse very quickly (over a period of about 4-8 weeks or 5000kms)

So anyway, with the timing being pulled back and given my car is heavier, I'd expect a "good" sedan to be 8 seconds (doing the same test I did, using VAGCOM). One doing 8.5 seconds could probably be quicker, but we might leave that for another day

I'll be keen to do the test again once the car is fixed for good.

Maybe my car is quicker again when it's running right, who knows, would be nice though .

Just keep in mind that the run I did was mostly ok, as the outside air temp was colder. During the day with outside air temp of 20 degrees C I was getting no kick at 5500 and random pinging. What happened was the symptoms I was getting at 20C 4-6 weeks later I was getting at 15C (outside temp).

Come summer in Australia, outside air temps will be 30C during the day. This would cause major problems (as it did last year). We're all running around trying to beat the hot weather.

This does show that the RS4 takes a huge performance hit when the temp rises into what I'd consider warm temps (hot is 40+ in Australia and cold is below 20 by the way )

Sport Auto did a test on the RS4 (both saloon and cab), trying to get the cab article...
80 to 120 kmh (50 to 75) 4th gear
saloon 4.8 (Audi spec ~4.7)
cab 5.7

this would tell me the 3rd gear 3k to 8k would have a similar difference, a cab might be 9 sec!

big difference...I would not touch your car, it's a 'special', lol

if the vaccum lines and flaps are not working it runs 10-15 degrees = 280PS and it requests to run rich at high revs - without codes for that.

Disconnect your airbox flap control line and block that vaccum hose. Make sure the airbox flap stays shut and see how the car performs - high intake temps can mean you are sucking in hot air from the radiators and that kills timing and performance and it feels flat.

Doug, which measuring blocks should I log?
Same as the one 2manytoys has posted?

yes - log that and log intake temps on another run - 004 iirc.

I need to do this also when im back from work,couldnt post up a step by step vagcom guide anyone?

Last question, Sport mode or not?

ok. What mines been doing is slowly losing timing. If the weather was 20C outside (and not coming into winter) the results would be more clear. Because it's been getting colder almost each day the timing looked to be falling off slower than what was actually happening.

The valves, flaps and pumps etc have been a focus point, as you and many others have said, the symptoms have pointed to it. I've been through two manifolds already (a third in a box ready to go), and had various actuators replaced, including pipes and fittings etc. A full vacuum "leak test" has been done too (many times).

The thoughts are now that excessive blow-by (too much oil) is the cause. Oh, the PCV was replaced too as the thought was it wasn't doing its job properly.

Would be interested to see what you do get on blowby. Talking to caldy last night, he put a oil catch can on as seen in his thread, has done 2000 miles since it was installed including the Euro Tour and he reckons there is only a trickle in the bottom of the can plus what's in the pipes so 15-20ml max?

That could point to blow by not being as excessive as anticipated.

Here's my log, looks like my 8.6 secs using DIS were a tad optimistic (1/2 tank of mainly V-Power, ambient 16.5 c)
To me it looks like Doug's prediction of rich mixture at full throttle
There are 2 runs there, latter only in Sport mode