Correcting Boost overshoots in ATR - Page 2 - BMW 3-Series (E90 E92) Forum

Ænema · 02-08-2013, 01:44 AM

Quote:

Originally Posted by Monster335

how about this one

You have to use the Accessport to add "Boost setpoint factor" and "MAF requested(WGDC)" to the datalogging list. Plug the AP in to the car and then add those two channels to the logging list before you get another log. Without those two pieces of information i can't tell you where you need to pull DC out.

Monster335 · 02-09-2013, 05:14 AM

Man thank you once again for taking the time to help me with this. I will repay you some way. I added the 2 components like you asked, I hope I did it correctly.

Ænema · 02-09-2013, 10:19 AM

Quote:

Originally Posted by Monster335

Man thank you once again for taking the time to help me with this. I will repay you some way. I added the 2 components like you asked, I hope I did it correctly.

Yeah, that's it.
Your overshoots are happening from 190g/s @ 2.1 Boost setpoint factor to 340g/s @ 2.49 boost set point factor. So that's where you'll want to pull some DC out. I've attached a pic of the changes i would make to the "WGDC (BASE)" table to get started fixing that. If these changes don't completely fix it then you will need to pull a little more out of whever the overshoots are still happening.

Monster335 · 02-10-2013, 01:43 AM

Thx again. Just to be sure...Do I take the actual e30 map file in the accessport (not the datalog file) and load into access tuner?

Fully_Bolted · 02-10-2013, 08:00 AM

Quote:

Originally Posted by Monster335

Thx again. Just to be sure...Do I take the actual e30 map file in the accessport (not the datalog file) and load into access tuner?

You can take transfer the E30 map file off your AP, or just download another from Cobb's website. Open it in ATR and make the adjustments. Save the file (make sure to assign a unique name) and transfer to your AP and reflash. Should only take ~2 mins to flash since not much changed.

n54door · 02-10-2013, 11:10 AM

These changes, would they need to be revised continually through the seasons?

Ænema · 02-10-2013, 12:15 PM

Quote:

Originally Posted by n54door

These changes, would they need to be revised continually through the seasons?

No, if you do it in winter then you should be fine year round. The WGDC adder table is able to compensate for underboosting in most cases.

Really, the only time I've had to add DC into the base table is when I started requesting a lot more load up top to run more boost closer to redline.

Fully_Bolted · 02-10-2013, 12:35 PM

Quote:

Originally Posted by n54door

These changes, would they need to be revised continually through the seasons?

To add to what aenema said, you will also need to revisit if you adjust your WG's or replace them. I had my turbos replaced under the extended WG rattle warranty and they are significantly "tighter" than my originals (40k miles). I had to reduce base WG DC tables by about 10%.

This also means that as your waste gates naturally wear over time, you might need to revisit the WGDC tables to add a little bit. This would probably be a few years though. For 95% of the users, it's a set it and forget it function.

Monster335 · 02-12-2013, 03:27 AM

Quote:

Originally Posted by Ænema

Yeah, that's it.
Your overshoots are happening from 190g/s @ 2.1 Boost setpoint factor to 340g/s @ 2.49 boost set point factor. So that's where you'll want to pull some DC out. I've attached a pic of the changes i would make to the "WGDC (BASE)" table to get started fixing that. If these changes don't completely fix it then you will need to pull a little more out of whever the overshoots are still happening.

Hey Aenema, Thx again for helping out a fellow member. I would like to repay you. I could send you some money (paypal?) so I could buy you a case of beer. Would that be ok with you?

Ænema · 02-12-2013, 11:43 AM

Quote:

Originally Posted by Monster335

Hey Aenema, Thx again for helping out a fellow member. I would like to repay you. I could send you some money (paypal?) so I could buy you a case of beer. Would that be ok with you?

I really appreciate the offer, but it's all good

Monster335 · 02-12-2013, 12:23 PM

Quote:

Originally Posted by Ænema

I really appreciate the offer, but it's all good

If you change your mind, offer still stands.

Monster335 · 02-14-2013, 12:14 PM

Quote:

Originally Posted by Ænema

You have to use the Accessport to add "Boost setpoint factor" and "MAF requested(WGDC)" to the datalogging list. Plug the AP in to the car and then add those two channels to the logging list before you get another log. Without those two pieces of information i can't tell you where you need to pull DC out.

So I ran some more logs after adjusting for over boost. Cobb says the throttle is closing due to actual load exceeding requested load. Begins at 2600 rpm so I have to adjust the WGDC base table. So I kinda have an idea where to start but adjusting what and how much is the problem. Are you able to help me out again? thx

Ænema · 02-14-2013, 02:28 PM

Sure thing, I'll take a look when I get home from work.

Glowin · 02-14-2013, 08:52 PM

Hey, is there a way to know you're getting these boost overshoots, without logging? Do you typically throw a code because of them?

The past summer, I took my stage 2+ car to the track, with the Cobb tune, and after just two laps, it went into limp mode. Could never figure out what it was. Car kept going into limp mode afterwards for a week or so, anytime I boosted more than 4/5 PST, to the point I was convinced that I had a boost leak, but could find none.

Then all of a sudden it went away after a couple of weeks by itself, and has been driving fine for months afterwards, up to 18 PSI boost no problems.

Ænema · 02-14-2013, 09:10 PM

Quote:

Originally Posted by Glowin

Hey, is there a way to know you're getting these boost overshoots, without logging? Do you typically throw a code because of them?

The past summer, I took my stage 2+ car to the track, with the Cobb tune, and after just two laps, it went into limp mode. Could never figure out what it was. Car kept going into limp mode afterwards for a week or so, anytime I boosted more than 4/5 PST, to the point I was convinced that I had a boost leak, but could find none.

Then all of a sudden it went away after a couple of weeks by itself, and has been driving fine for months afterwards, up to 18 PSI boost no problems.

As far as the boost overshoots go, it depends on how badly the overshoots are. If it is severe enough to cause the to TPS to dip to ~40%(or worse) then you will probably feel it as a hiccup during acceleration. Or it may cause boost oscillations and you'll definitely feel those.

As far as limp mode goes: No, it will not cause that. You'll need to find out the codes that were triggered and go from there, if it hasn't happened in months then it may have just been a fluke or something.

raceyBMW · 02-14-2013, 10:16 PM

Track seems to expose vanos related issues, which can show up only at high rpm runs like you usually have at the track. Only way to know for sure is to read the codes.

Ænema · 02-15-2013, 12:59 AM

Quote:

Originally Posted by Monster335

So I ran some more logs after adjusting for over boost. Cobb says the throttle is closing due to actual load exceeding requested load. Begins at 2600 rpm so I have to adjust the WGDC base table. So I kinda have an idea where to start but adjusting what and how much is the problem. Are you able to help me out again? thx

OK, here we go. I'll walk you through the process of identifying where and hhow much WGDC Base changes to be made.

First thing to do is to figure out where the overshoots are happening. To do this open up the CSV file.

Then look for where your Accel Ped. Pos. goes to 99%, that will let you know when you go WOT. Then go to TPS ACT and it should be at 80%.
Then start following the log until:
-TPS ACT drops BELOW 80%
-Boost Mean ABS will overshoot Req Boost Abs(and as a consequence Act Load will overshoot Requested load)

That is where the overshoots are happening. After you know where the overshoots are occuring it's just a matter of pulling DC out of the Base tabe where those overshoots are occurring.

NOTE: this map is going off of the changes already made in the pic of the "fix" above. If your starting values are different then your ending changes will be different
So you'll pull some more DC out. Like i've said, 10%-15% is a good rule of thumb, however when you see BIG drops in TPS(like 40% readings or less) it's not a bad idea to pull a little more out.

Once your changes are finished then save the map, transfer to the AP and re-log. Rinse and repeat the process until the TPS drops are gone.

Monster335 · 02-15-2013, 03:27 AM

Thanks for the explanation, I kinda get what you are saying. I now know how to find the overshoots. One question I have for you is in the Access Tuner Race program, when I load the map and look at the WGDC Base table, I notice the top left for me it shows "MAF Req. (WGDC) (kgh)" but looking at your table it shows "MAF Req. (WGDC) (gs)".....is there some kind of conversion I need to make changes on? Thanks again.

Monster335 · 02-15-2013, 03:42 AM

The other thing is Im confused on is, where to start pulling the DC and making the adjustments on WGDC base table on ATR when looking at the datalog. Hope that makes sense.

Fully_Bolted · 02-15-2013, 06:12 AM

Quote:

Originally Posted by Monster335

Thanks for the explanation, I kinda get what you are saying. I now know how to find the overshoots. One question I have for you is in the Access Tuner Race program, when I load the map and look at the WGDC Base table, I notice the top left for me it shows "MAF Req. (WGDC) (kgh)" but looking at your table it shows "MAF Req. (WGDC) (gs)".....is there some kind of conversion I need to make changes on? Thanks again.

Yes, you need to change the units of measure to standard vice metric. Somewhere under the settings menu in ATR.

Fully_Bolted · 02-15-2013, 06:16 AM

Quote:

Originally Posted by Monster335

The other thing is Im confused on is, where to start pulling the DC and making the adjustments on WGDC base table on ATR when looking at the datalog. Hope that makes sense.

In the areas that you are overshooting your requested boost, note the boost set point factor and MAF requested WGDC. These are your references to the table axes.

Ænema · 02-15-2013, 10:55 AM

Quote:

Originally Posted by Monster335

Thanks for the explanation, I kinda get what you are saying. I now know how to find the overshoots. One question I have for you is in the Access Tuner Race program, when I load the map and look at the WGDC Base table, I notice the top left for me it shows "MAF Req. (WGDC) (kgh)" but looking at your table it shows "MAF Req. (WGDC) (gs)".....is there some kind of conversion I need to make changes on? Thanks again.

click edit-> configure options-> display-> show standard units

02-14-2013, 02:28 PM	#35
Ænema Captain Drives: BMW Join Date: Aug 2012 Location: Arizona Bay Posts: 864 iTrader: (0)	Sure thing, I'll take a look when I get home from work. __________________ "I'm not surprised you get along well with all the other neighbours. If you put fifty children with Down's syndrome in a room there is going to be a lot of hugging." David Thorne

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02-10-2013, 01:43 AM	#26
Monster335 Private First Class Drives: jet black 3 series n54 2010 Join Date: Feb 2011 Location: U.S.A. Posts: 118 iTrader: (0)	Thx again. Just to be sure...Do I take the actual e30 map file in the accessport (not the datalog file) and load into access tuner?

02-10-2013, 11:10 AM	#28
n54door Lieutenant Drives: 2008 135i Join Date: Sep 2011 Location: DFW Posts: 443 iTrader: (4)	These changes, would they need to be revised continually through the seasons?

02-14-2013, 08:52 PM	#36
Glowin Captain Drives: 335i Join Date: Jun 2009 Location: Seattle Posts: 704 iTrader: (0)	Hey, is there a way to know you're getting these boost overshoots, without logging? Do you typically throw a code because of them? The past summer, I took my stage 2+ car to the track, with the Cobb tune, and after just two laps, it went into limp mode. Could never figure out what it was. Car kept going into limp mode afterwards for a week or so, anytime I boosted more than 4/5 PST, to the point I was convinced that I had a boost leak, but could find none. Then all of a sudden it went away after a couple of weeks by itself, and has been driving fine for months afterwards, up to 18 PSI boost no problems.

02-14-2013, 10:16 PM	#38
raceyBMW king of the hills Drives: 335i coupe Join Date: Dec 2006 Location: Denver, CO Posts: 2,462 iTrader: (1) Garage List 1994 530i [4.25] 2007 335i Coupe [4.07]	Track seems to expose vanos related issues, which can show up only at high rpm runs like you usually have at the track. Only way to know for sure is to read the codes.

02-15-2013, 03:27 AM	#40
Monster335 Private First Class Drives: jet black 3 series n54 2010 Join Date: Feb 2011 Location: U.S.A. Posts: 118 iTrader: (0)	Thanks for the explanation, I kinda get what you are saying. I now know how to find the overshoots. One question I have for you is in the Access Tuner Race program, when I load the map and look at the WGDC Base table, I notice the top left for me it shows "MAF Req. (WGDC) (kgh)" but looking at your table it shows "MAF Req. (WGDC) (gs)".....is there some kind of conversion I need to make changes on? Thanks again.

02-15-2013, 03:42 AM	#41
Monster335 Private First Class Drives: jet black 3 series n54 2010 Join Date: Feb 2011 Location: U.S.A. Posts: 118 iTrader: (0)	The other thing is Im confused on is, where to start pulling the DC and making the adjustments on WGDC base table on ATR when looking at the datalog. Hope that makes sense.