Lost the kick at 5000 rpm

[2manytoys]

Don't worry about sport mode, it's just a gimmick. I'd be amazed if opening the flap in the exhaust actually added anything that can be measured with respect to peak power.

I measured blocks:
3 - revs, airflow, Throttle position, timing angle
31 - Lambda (Air Fuel)
20 - Timing <beep> on Cylinders 1, 2, 3, 4

I also measured block 11 in another run so I could see intake air temp.

I'd say measure 3, 11 and 20, I'd be keen to see a 3rd gear run. Just remember to press the turbo button.

[2manytoys]

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

You have an AFR of around 12.5, that's not too rich is it?

It would be good to see a run done with the VACGOM turbo button pressed

[neckarsulm]

I was looking at lambda of 0.85 at WOT which looks rich but what do I know?

[2manytoys]

Yep, Lambda 0.85 is about 12.5 AFR. I think mine measured 13.1 AFR on the dyno but VAGCOM measured 0.85 too (probably about the same anyway). I wouldn't consider 12.5 rich, but I haven't seen too many RS4 AFR's so I'm not too sure myself.

[Sims]

Yep, Lambda 0.85 is about 12.5 AFR. I think mine measured 13.1 AFR on the dyno but VAGCOM measured 0.85 too (probably about the same anyway). I wouldn't consider 12.5 rich, but I haven't seen too many RS4 AFR's so I'm not too sure myself.

Forget the AFR's, get a GTR - sorted

[neckarsulm]

My intake air temp didn't change, should the air box flap opening affect this?

[2manytoys]

My intake air temp actually went down as I was doing the runs (I guess 3rd gear runs will do that given the massive amounts of air being pushed into the car at those speeds). I wouldn't worry about yours staying the same. My intake temps were almost exactly the same as yours with those outside air temps.

Sims - Hey, I've been thinking about an R34 GTR, the new shape just doesn't do it for me, however it's going to be hard to give up the V8 sound and the cab. Also, I'm not sure if I would be able to handle all the kids at the traffic lights wanting to race me.

[Sims]

Sims - Hey, I've been thinking about an R34 GTR, the new shape just doesn't do it for me, however it's going to be hard to give up the V8 sound and the cab. Also, I'm not sure if I would be able to handle all the kids at the traffic lights wanting to race me.

Let the kids win.

[neckarsulm]

So does anything look suspect in my data then?
I know there are plenty of variable and I shouldn't be too worried about being a bit off the guide times, just want to know everything is working OK more than anything.

Lengster, I used ADVANCED MEASURING BLOCKS instead of the normal one as it allows you to pick which fields you want to log rather than having the blocks of 4.

[ArthurPE]

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.

I concur
imo the deposit is from valve guide seal seepage...

I've seen other catch cans, no oil (at least measureable), only water

in fact didn't one guy actually have it vented to atm and the valves were fouled after only a short mileage?

[Doug_S2]

The flow numbers look ok for a car that will dyno 370-380PS (150g/s) - timing is ok and fueling is spot on for stock car.

A car with a new engine will flow 165g/s per bank.

[silverRS4]

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

There is absolutely nothing wrong with that log, or Mal's. The AFR for peak torque in a naturally aspirated engine is approximately 12.5-13.0. The 0.85 lambda is exactly that - 12.5. If you saw the table for target lambda at high engine loads, it is .85. You can also see right on your log, group 31 field 1 that the "specified lambda" is indeed .85.

The other notable point is the fact that your car and Mal's start to pull back timing at high rpm's when the intake air temp is 36C. Good grief, what do you guys expect? That is completely normal, even with 98/99 RON. What you have uncovered with your logging is a very well tuned engine running exactly like it should. In sub 20C weather, mass flow is higher, there is little timing correction and 3rd gear 3000-8000 occurs in the mid 8's. When IAT's are 35C+, timing correction increases, mass flow is lower and acceleration tests are substantially slower.

And as you pointed out, the 3000-8000 rpm "test" can be done with much better accuracy with Vagcom. Just set the sample rate to Turbo Mode and log only a few blocks and your sample rate will be very high.

[ArthurPE]

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

time ~10 sec
mixture is perfect
timing is perfect

my bet, flaps

[silverRS4]

A car with a new engine will flow 165g/s per bank.

Not when the IAT is 36C. You need to be more careful with your comments or RS4 people will start looking for airflow problems where there are none, i.e. "Why can I only get 150 g/s?, what's wrong with my car?" If you determined the volumetric efficiency of an RS4 that's pulling in 150 g/s per bank at 36C, you'd see it's in line with a healthy RS4.

[ArthurPE]

bravo
someone had to say it...

mal 5700 to 8000 4 sec
neck 5 sec

not sure whether it's resolution or whatever, but the car is running fine...

this would lead me to deduce
deposits do not impact timing
deposits do not impact mixture

at least for these 2 cars

There is absolutely nothing wrong with that log, or Mal's. The AFR for peak torque in a naturally aspirated engine is approximately 12.5-13.0. The 0.85 lambda is exactly that - 12.5. If you saw the table for target lambda at high engine loads, it is .85. You can also see right on your log, group 31 field 1 that the "specified lambda" is indeed .85.

The other notable point is the fact that your car and Mal's start to pull back timing at high rpm's when the intake air temp is 36C. Good grief, what do you guys expect? That is completely normal, even with 98/99 RON. What you have uncovered with your logging is a very well tuned engine running exactly like it should. In sub 20C weather, mass flow is higher, there is little timing correction and 3rd gear 3000-8000 occurs in the mid 8's. When IAT's are 35C+, timing correction increases, mass flow is lower and acceleration tests are substantially slower.

And as you pointed out, the 3000-8000 rpm "test" can be done with much better accuracy with Vagcom. Just set the sample rate to Turbo Mode and log only a few blocks and your sample rate will be very high.