NefMoto

Hi everyone and thanks for any assistance in advance.

Vehicle:
2001.5 s4 b5 2.7t 6mt
Dar Intake
710N DVs
Pressure tested and replaced a bunch of vacuum lines last weekend
All sensors in place and working correctly.  No MIL

Issue:
From around 3500 to 4500 rpm I am getting torque loss. You can see drops in duty cycle and on time of the injectors. There is also a fluctuation in boost during the same rpm range.

I'm pretty noobish when it comes to me7 tuning but have assoc. in mechanical engineering so feel free to use technical terms. Anything I don't understand I will wiki. I just need a little help getting pointed in the right direction.

I am leaning towards the idea of it being related to VVT vs non-VVT timing interpolation as I've read the change over is in this rpm range. I've made small adjustments to fueling and boost in this range but didn't note any positive effects to the logs or the butt-dyno.


 

that log actually looks fine. A bit of boost wiggle but not a lot. Honestly, there isn't much i'd change.

Thank you. I'll take that as a compliment coming from you. This is the first tune I put together myself but i definitely wouldn't have been able to do it without the wiki,logger and many of  forum topics full of your post.

The car feels really good considering how stock it is and I'm not planning on pushing this tune any further without some hardware upgrades. I just want to understand a little more what is going on in this range.

Any info you can give me on why there is a negative deviation across all the maps. This log was recorded on a slight incline as I was dealing with the road given on my way home from work. My FATS is a little higher on this run than normal but overall the logs do the same thing on a section of flat freeway that I normally log on.

Seriously. You did a great job. You should be proud!


Yea, your WGDC is maxed out after 5700 rpm! Might want to pull a bit of requested load up there, you're also out of injector.

Look at your I-limit trims... you can see what the PID is trying to compensate for.

Thank you. I'm going to check it out. I did notice I was out of injector on the big end which surprised me as I've heard a lot of people say stock injectors would support a good chunk of mods. Would I be correct in saying that I won't gain much max tq/hp output by doing a turbo-back on the stock injectors but would notice improvements in responsiveness, spool times and lower egts? I don't really see how I could get more power without more fuel. 

I'm adjusting to the new-found power faster than I can find more. Something "bolt-on" is going to have to happen soon.

This. You are done w/o injectors. BTW once you go non-OEM fueling you MUST HAVE A WIDEBAND

I can't stress this enough!

You could also try a 5 bar fpr, but it won't give you much.

BTW Wiki to the rescue again. As many times as I've read it how the heck did I miss this...

Cam changeover effect on requested boost

Motronic likes to change requested boost depending on cam position. While it may seem like a good idea in theory, in practice, abrupt changes in requested boost near the MAP limit can make the boost PID unhappy. When logging, you may see an odd notch in requested boost between 3000 and 4000 RPM. These maps are what is causing that notch
KFPBRK - Correction factor for combustion chamber pressure
KFPBRKNWS - Correction factor for combustion chamber pressure when NWS active
KFPRG - Internal exhaust partial pressure dependent on cam adjustment when sumode=0

Also flatten KFTARX under 20C.... looks like you are logging in very cold conditions, and it is pulling max load.

for reference

http://nefariousmotorsports.com/forum/index.php?topic=6695.msg72957#msg72957

log rlmxko and you can see the effect of KFTARX (frxta)

Well still haven't been able to get logs to see if I corrected my issue. Unfortunately I've developed a boost/vac leak somewhere around the drivers side IC piping. I cleaned and tightened up the hoses I could get to easily but didn't fix my issue. I have the home-made pressure tester I made the last time I was having vac issues, just don't have a compressor to pressurize it. I need a friend with a shop!!! Blew out a tire on sat because of these stupid potholes so I sprang for a set of 4 totally killing the Audi fund for a while or else I'd be on my way to buy a compressor.So for now its special thanx to phili_dot and his switch on the fly bin/xdf because its back to the stock file for me :-\

http://nefariousmotorsports.com/forum/index.php?topic=6695.120

There is some good discussion on that there.
Flyboy's graph and Dave's response.