UrS4 2.2T Avant project

[Acki]

Forget flushing with brake cleaner, my experience. ;-)
Install filter mesh inline and check the mesh over mileage. When mesh is clean for longer periods (should be in this status after 250-500km) you can remove the filter.
I would kick the mesh out after 1000km (when the mesh has no bypass).

The graph is very smooth. I can't say what's the reason for the torque loss.
Some video you don't have from a dyno run? Engine/exhaust sound tells often a lot.

I don't know the timing of 20V engines.
Boost level should also be a part of the dyno plot.
When you have 2bar over boost and later only 1bar it would also explain this drop.

[Thuppu]

Engine sounded healthy, nothing strange there. Just looked at some logs... Boost 2.5bar, and 2.15bar at 8000rpm. But there is some strange thing, Vemstune tells Trigger error (Less Pr.trig) between 6900-7900rpm's. So I guess there is some trigger problems after all..? Funny thing that you couldn't hear anything strange, no cuts or rattle, nothing strange..?

Edit. The dyno curve starts to drop way earlier than the error occur, so it's propably not the problem here.

[prj]

There is no reason whatsoever to rev the engine that high. 7.6k is ok with HX40S.
The graph looks like a mess, something is definitely amiss here. The torque should not drop like that, and you are missing at least 100hp.

The spoolup torque curve looks very wrong as well, how is boost control done?

[newsh]

Did you log AFR?

[Billman]

maybe you can post the vemslog file from that dyno run.

[mushasho!]

Yes, post log... Attachment preferred

Sent from my HTC One using Tapatalk

[Thuppu]

Here is the log of the last pull we did. The last 6-7 pulls where more or less the same result.I'm not sure from which one the plot are. (remove the last .txt of the file)

Boost control is with the Turbosmart mechanical tee.

[Thuppu]

And the reason for revving up to 8k was because I wanted to see how much the power dives in the end, and also to see if the engine can handle that.

[kenax]

It's all in the log.

[popdemonic]

Engine sounded healthy, nothing strange there. Just looked at some logs... Boost 2.5bar, and 2.15bar at 8000rpm. But there is some strange thing, Vemstune tells Trigger error (Less Pr.trig) between 6900-7900rpm's. So I guess there is some trigger problems after all..? Funny thing that you couldn't hear anything strange, no cuts or rattle, nothing strange..?

Edit. The dyno curve starts to drop way earlier than the error occur, so it's propably not the problem here.

Thomas,
what's your vems firmware?some of firmwares caused the Tr.Error on the top RPM due to intermittent signal from flywheel sensors.the later firmwares coped good with them.

[V6quattro]

I also had problems with the stock audi triggers. So i changed the primary trigger with a 60-2 hall sensor and all is fine. And if i'm right my turbo is a little bigger than yours but my spool is way sooner. Did you all-ready tried a boost leak test?

[Thuppu]

This was the first test with VEMS. I had good hopes on it, because I couldn't feel or hear any stutter or misses, it was revving nicely up to the limiter. Apparently I was wrong, because the trigger error flag is there, miss the Motronic already. So what is the symphtons of the trigger error, could it cause this problem?

Only small boost leak I have is from the throttle body axle. It's so small that it could never effect this way. Checked the leaks well before going to the dyno.

[Rocco]

have you became in your own tuner Thomas?


your van is the perfect sleeper,fast,confortable and free time eater

[A80Avant]

This was the first test with VEMS. I had good hopes on it, because I couldn't feel or hear any stutter or misses, it was revving nicely up to the limiter. Apparently I was wrong, because the trigger error flag is there, miss the Motronic already. So what is the symphtons of the trigger error, could it cause this problem?

Only small boost leak I have is from the throttle body axle. It's so small that it could never effect this way. Checked the leaks well before going to the dyno.

In vems a trigger error could be anything from a poor coil pack to a poor reading from the trigger sensors. Given that you should be seeing a better curve in torque there could be something actually wrong. Otherwise I have always had the odd error without any engine symptoms or power loss.

I will try and put the log details into my power software to see if it matches the dyno curves in any way.

Let me know of your wheel size and approx. Car weight even though actual figure not what we are aiming to show here.

[Thuppu]

Wheel size 235/40/18, car weight could be close to 1600kg. There is a small dent in the curve at 5500rpm's, its a fuelcut. The boost limit was set at 350kpa and seems that the boost slightly spiked over the limit.