Oscillation in power with Cobb V4.01 maps on 335is

MnMnM · 06-01-2013, 10:56 PM

Guys
Im using the COBB AccessPort Tuner. I've been reading about how the V4.02 maps solve the problem of power oscillations for the Stage II+ boys. My problem is that I have no mods on the car and have been using V4.01 maps, both Sport and Aggressive (Stage I) on my 2011 335is.
While the power gains are significant, the power is not smooth at all. Surging occurs when going to WOT during any pulls in 2nd, 3rd, 4th etc.
If I go WOT from a standing start, it seems to gone or less noticeable. Most noticeable when heavier loading is on the engine. I've used both 91 AND 94 octane fuel.
If I return to the stock map, then all is normal again, but once you've upped the power once, you can't go back.

I'm using the IKBOS IS maps and assume they are correct as they are the ones shipped with my AccessPort.

I'm hoping someone can help me get to the bottom of this as I do enjoy the power, but the oscillation/surging is frustrating. You can actually hear it through the exhaust too.

Cheers

E90Company · 06-01-2013, 11:15 PM

You have to remember this is a flash tune, and OTS maps are really just a tuning "base". Every car is different, so you need to make adjustments to your base OTS map in order better tune to your own car. Boost oscillations are one of the easiest things to tune out using ATR. Start by doing some logs, making sure "Boost setpoint factor" and "MAF requested(WGDC)" are checked off. When you do this, you can see your throttle oscillations (at what RPM, load level, etc) in the CSV log, and make adjustments to your WGDC Base and PID tables to tune it out and better suit your car. I would also reccomend geting a pro-tune if you don't like messing with ATR, because the tuner will fix your oscillation issues as well as extract more power out of your current base map.

MnMnM · 06-04-2013, 10:38 PM

Been scouring the forums and I can't find anyone else having oscillation problems with Stage I. I bought the AP because it appeared easy. I have no desire to start tweaking with Cobb's maps.

I just wish the problem would go away.

COBB Tuning · 06-04-2013, 10:51 PM

Add 'Boost Setpoint Factor' and 'MAF Req (WGDC)' to your log list... remove a couple Timing Correction monitors to make room, then get me a log of 3rd gear WOT from around 2000 rpm to as close to redline as safely possible with all traction control turned off.

Email me the logs and I'll see what we can do. You most likely have some overly tight wastegates.

josh.dankel@cobbtuning.com

- Josh

06-01-2013, 10:56 PM	#1
MnMnM Private 14 Rep 62 Posts Drives: 2018 X5 M, 2013 M3 Join Date: Apr 2009 Location: Victoria, BC, Canada iTrader: (0)	Oscillation in power with Cobb V4.01 maps on 335is Guys Im using the COBB AccessPort Tuner. I've been reading about how the V4.02 maps solve the problem of power oscillations for the Stage II+ boys. My problem is that I have no mods on the car and have been using V4.01 maps, both Sport and Aggressive (Stage I) on my 2011 335is. While the power gains are significant, the power is not smooth at all. Surging occurs when going to WOT during any pulls in 2nd, 3rd, 4th etc. If I go WOT from a standing start, it seems to gone or less noticeable. Most noticeable when heavier loading is on the engine. I've used both 91 AND 94 octane fuel. If I return to the stock map, then all is normal again, but once you've upped the power once, you can't go back. I'm using the IKBOS IS maps and assume they are correct as they are the ones shipped with my AccessPort. I'm hoping someone can help me get to the bottom of this as I do enjoy the power, but the oscillation/surging is frustrating. You can actually hear it through the exhaust too. Cheers
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06-01-2013, 11:15 PM	#2
E90Company Major General 198 Rep 6,136 Posts Drives: Car Join Date: Mar 2012 Location: FL iTrader: (2)	You have to remember this is a flash tune, and OTS maps are really just a tuning "base". Every car is different, so you need to make adjustments to your base OTS map in order better tune to your own car. Boost oscillations are one of the easiest things to tune out using ATR. Start by doing some logs, making sure "Boost setpoint factor" and "MAF requested(WGDC)" are checked off. When you do this, you can see your throttle oscillations (at what RPM, load level, etc) in the CSV log, and make adjustments to your WGDC Base and PID tables to tune it out and better suit your car. I would also reccomend geting a pro-tune if you don't like messing with ATR, because the tuner will fix your oscillation issues as well as extract more power out of your current base map.
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06-04-2013, 10:38 PM	#3
MnMnM Private 14 Rep 62 Posts Drives: 2018 X5 M, 2013 M3 Join Date: Apr 2009 Location: Victoria, BC, Canada iTrader: (0)	Been scouring the forums and I can't find anyone else having oscillation problems with Stage I. I bought the AP because it appeared easy. I have no desire to start tweaking with Cobb's maps. I just wish the problem would go away.
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06-04-2013, 10:51 PM	#4
COBB Tuning Major 238 Rep 1,051 Posts Drives: 335i Join Date: Dec 2010 Location: Austin, TX iTrader: (0)	Add 'Boost Setpoint Factor' and 'MAF Req (WGDC)' to your log list... remove a couple Timing Correction monitors to make room, then get me a log of 3rd gear WOT from around 2000 rpm to as close to redline as safely possible with all traction control turned off. Email me the logs and I'll see what we can do. You most likely have some overly tight wastegates. josh.dankel@cobbtuning.com - Josh
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