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BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N55 Turbo Engine Tuning and Exhaust Modifications - 335i Tuning > Cobb Logs



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      12-27-2012, 12:49 PM   #1
trk411
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Cobb Logs

Well, I did some logging today. Rather new at logging, so not sure how good they are. In any event, I haven't a damn clue how to properly create a chart for the logs. I did convert them to .txt and attached them. Anyone care to do anything or interpret the logs? Any info/help is appreciated.

Edit: If anyone is interested, I can email you the .xls files directly.

Tom
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File Type: txt Log.txt (17.9 KB, 339 views)
File Type: txt Log2.txt (14.7 KB, 303 views)

Last edited by trk411; 12-27-2012 at 01:44 PM..
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      12-27-2012, 05:34 PM   #2
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I know this thread is useless at this point, but I think Slops is going to put the data into a graph. FWIW, I played with the Cobb template for graphing for about 2 hours with no luck. Forgot to add before that pulls were in 3rd gear.
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      12-27-2012, 05:35 PM   #3
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I've added some graphs to your logs. Looks like your temps are getting up there and the boost barely breaks 12psi. For stage 1 it looks fine. I'm guessing you are a stock car? The timing isn't that bad though but there def. insn't that much advancing going on at this point.
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      12-27-2012, 05:41 PM   #4
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Thanks man! Yeah, I was surprised at the boost levels. Thought it would be higher based on what Cobb said. Only mods are BMW PE and BMS charge pipe. I have a BMS intake, but it was off for the logging. Can you expand a bit regarding your comment on timing advance?
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      12-27-2012, 06:16 PM   #5
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I always play with the rule of thumb being that your ignition advance get back to 10 positive degrees and if all things are positive... Fuel octane, boost, intake air temps then you should be able to advance timing to around 14 deg! Advancing timing means you give the mixture more time to fully combust and therefore give you more power in laments terms.

So far your looking at one big thing counting against you for timing advance, and that is your high inlet air temps. I'd hate to see what a full 1-4 gear pull would look like if only one gear heats that air temp up like that. It's normal though but I guess I'm used to my meth lowering the intake air temps
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      12-27-2012, 06:28 PM   #6
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Gotcha. I wonder what the deal is with the boost. I thought for sure I would be above 12 for a while, but it seemed to peak just over 12. Not sure what the boost spike after letting off the gas is all about.
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      12-27-2012, 06:33 PM   #7
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From what I've seen most ECU tunes control mass air flow rate, on cold days the boost is lower because the air is more dense. I've seen this in my data logs, boost pressure is lower now that it s cold, but mass air flow is the same.
Good old Ideal Gas Law, PV=mRT.
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      12-27-2012, 06:42 PM   #8
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Quote:
Originally Posted by Suds
From what I've seen most ECU tunes control mass air flow rate, on cold days the boost is lower because the air is more dense. I've seen this in my data logs, boost pressure is lower now that it s cold, but mass air flow is the same.
Good old Ideal Gas Law, PV=mRT.
I agree with you there! The car certainly feels strong with even only 12 psi.

I would love to log mine to compare but my obd2 needs fixed first. Connections are loose. Im wondering if the new charge pipe may have introduced a boost leak?
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      12-27-2012, 06:54 PM   #9
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Quote:
Originally Posted by Slops View Post
I agree with you there! The car certainly feels strong with even only 12 psi.

I would love to log mine to compare but my obd2 needs fixed first. Connections are loose. Im wondering if the new charge pipe may have introduced a boost leak?
Don't think so. I am meticulous when I install stuff. I checked and double checked the connections. All is tight. It was only 28 degrees here today, so maybe what Suds said rings true. Either way, the car pulls like a mother.
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      12-27-2012, 07:04 PM   #10
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I'm looking forward to seeing some independant dyno results. Either of you plan on doing a before and after run? With it only taking 20 minutes or so to install it shouldn't be too hard to compare back to back.
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      12-27-2012, 07:15 PM   #11
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Quote:
Originally Posted by ziominix View Post
I'm looking forward to seeing some independant dyno results. Either of you plan on doing a before and after run? With it only taking 20 minutes or so to install it shouldn't be too hard to compare back to back.
I wish I could. My days are so damn busy that I doubt I will ever get to a dyno.....
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      12-27-2012, 07:36 PM   #12
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I'm not particularly interested to dyno stage1 at this point. Maybe s2 later
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      12-27-2012, 10:34 PM   #13
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Understandable.

Your also in an xi, so I'll be sure to keep an eye out for your progress. Is your car a stick as well?
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      12-28-2012, 06:33 AM   #14
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Quote:
Originally Posted by ziominix View Post
Understandable.

Your also in an xi, so I'll be sure to keep an eye out for your progress. Is your car a stick as well?
Yup, 6MT
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