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Author Topic: Boost problem  (Read 22151 times)
nubcake
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« Reply #30 on: November 23, 2015, 04:05:16 PM »

I guess I'll just bump this thread instead of starting a new one.
So, I'm tinkering with another RS6, stock turbos. What got me wondering - is there a way to improve turbo spool-up? Attached is the piece of log that got me thinking towards that. I didn't like that N75 goes down waaay before turbos are making proper boost.

Is there any way to improve that? Should I ramp up LDRXN more aggressively? Say, increase it from 2500 to 3000 in my example. Will it make any difference? Should I even bother or that won't give me any noticeable result? What it considered a good practice?  Grin

Thanks!


EDIT: Now, after posting it I've noticed the wrong forum section. I guess this rather belongs to "tuning" section, not "diagnostics". :\
« Last Edit: November 23, 2015, 04:09:06 PM by nubcake » Logged
nyet
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« Reply #31 on: November 23, 2015, 04:11:47 PM »

Please post an actual log, preferably not from VCDS.
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ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
nubcake
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« Reply #32 on: November 23, 2015, 04:24:39 PM »

Unfortunately, that's all I have for now. Car is in other country, no way to log it properly. VCDS log won't tell you anything extra over what I already posted.
Basically, we can ignore the "look at the log" part and concentrate on "what is the good way to keep N75 open longer during spool". Wink

Cheers!

EDIT: (I just love to add stuff after I had initially posted, aye)
N75 is being properly controlled, with very little over/undershoot, the whole PID is stock. The only part that bugs me is this weird "sooner-than-I-like" DC decreasing during spool-up.
« Last Edit: November 23, 2015, 04:28:27 PM by nubcake » Logged
nyet
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« Reply #33 on: November 23, 2015, 04:39:12 PM »

Yes, you can bring in LDRXN early such that during spool, N75 is maxed.

Two possible side effects:

1) bring it in too early, and you may get a positive deviation (underboost, sometimes mislabled as overboost) code.
2) nothing happens, and DC still gets cut too soon means you may have to numb Q2
Logged

ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
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