Subaru WRX Forum banner

The Official datalog review thread

28K views 25 replies 8 participants last post by  mccaguej 
#1 ·
Hey guys, thought I would make a little thread for datalog reviews since from time to time we have members who need it. I know there's only a hand full of you experienced enough to read them and know what your looking at so, If you don't mind helping out your fellow members please do! If your too busy or just don't want to the that's fine as well. To the ones who want to help, just let us know your preferred gear and parameters to log. I know usually it's WOT in 3rd gear 2.5k rpm-redline. If your profile is not up to date you will also need to include info about your modifications. As far as posting logs, Google Docs has a service where you can upload your spreadsheet files and you can post a link for others to view. This is a free service. Redirecting... . Someone may know some other or easier ways they can share as well. This thread can also be a good way for some of us who don't know a lot about it like myself, to gain knowledge and insight into tuning. If anyone has anything to add, please feel free. Thanks in advance to our tuning gurus nice enough to participate.


Here are some parameter definitions to help out.

PARAMETER DEFINITIONS

Seconds (sec)[AP] or Time(ms)[RR]

This is the time elapsed during the datalog. RR datalogger lists this time in milliseconds.

RPM (RPM) [AP] or Engine Speed (RPM) [RR]

This is your engine speed. Measured in RPM.

Calculated Load (load) [AP] or Engine Load (1 byte) (g/rev) [RR]

This is the load on the engine. It is calculated by using data from the MAF sensor to calculate how much air is entering the engine per revolution. Engine load is used throughout the ECU as a variable to control the ECU's tables regarding everything from ignition timing and AVCS timing to how much fuel is used.

Dyn. Adv. Mult. (DAM) or IAM [RR]

This is used as part of Subaru's knock control strategy. The Subaru ECU pulls timing to reduce knock and in extreme cases can richen the fuel mixture and disable boost control leaving you at wastegate boost. This value is multiplied to the timing advance table and added to the Base timing table to create the maximum timing advance. If the value is 1 full timing advance is being used. If the value is less than 1 only that fraction of the timing advance table is being used.

ex. If the DAM equals .5 and the timing advance table calls for 5 degrees advance. .5*5 = 2.5 degrees will be added to the base timing.

What you need to know. The DAM is set in a stock ecu to .5 after ecu reset. The tuner may modify this value to start at any value they want. Generally as you drive around this value will increase to 1. You will need to be at engine loads that apply timing advance to raise this multiplier as well as other factors. If your car does not raise this DAM or reduces it. It is because of feedback from the knock sensor. This is an indication that either knock is occurring or false knock is being picked up through the knock sensor. It is a safety precaution when bad gas or low octane gas is used.

If the value drops below .35 the alternative open loop enrichment table is used. This is a much richer table then the normal open loop enrichment table.

If the value drops below .2 the ECU disables Boost control. This will leave you car running at wastegate boost and you will always have 0% Wastegate Duty Cycle. It will not be turned back on till the DAM increases to above .65.

The value you are looking for is a DAM of 1 (32 bit ecu) or 16 (16bit ecu)

Ignition Adv. (deg)[AP] or Ignition Total Timing[RR]

This the total amount of ignition advance currently being used by the engine. It is measured at cylinder 1 so 'per cylinder' ignition changes will only be seen if they are applied to cylinder 1

Learned Ign. (deg)[AP] or Ignition Timing Advance (degrees)[RR]

This is the amount of timing that is added to ignition base timing to create the total timing used.
It is calculated by
DAM* Timing advance table - Knock Correction - Knock Learning
Or To RR users
IAM*Timing advance table – Feedback Knock Correction – Fine Learning Knock Correction.

Knock Correction (deg)[AP] or Feedback Knock Correction(degrees)[RR]

This is the total timing being pulled when the ECU picks up a knock event. This is an indication that the ecu has detected knock from the knock sensor. It will continue to pull timing for a period of time after knock has occurred. If the ECU sees another knock event additional timing will be pulled. Although this can be changed by the tuner generally -1.4 is used for each knock event.

What you need to know. It is important to not see Knock Correction at high engine loads from about 1.8 up. It would be ideal to not have any knock events at all even at low loads. However the knock sensor may hear other noises that it cannot distinguish from knock. Sometimes rattling heat shields, clutch and transmission noises or even loose bolts or nuts sitting on top of the engine can set off the knock sensor.

Knock Learning (deg)[AP] or Fine Learning Knock Correction (degrees)[RR]

This is the timing being pulled when the ECU has learned to pull timing to protect from knock. Over time the ECU will slowly advance timing back as long as no new knock is occurring. Timing will be pulled in increments of -1.4. The knock sensor is used by the ECU to determine if knock is occurring.

Knock Sum

"Knock sum will increment at idle and low RPM where the ECU is extremely poor at distinguishing actual knock from other engine noises. This is why the ECU does not respond to "knock" events in this area. The knock sum value itself is meaningless because of this. You have to look at when it increments and ignore changes at idle and low RPM/load. Cylinder #4 will see more counts even on a stock engine, likely due to the relationship between the placement of the knock sensor on the block and cylinder #4.

Bill" (from Bill at Cobb)

Throttle Position (%)[AP] or Throttle Opening Angle(%)[RR]

This displays the current throttle position. Because Subaru doesn't use an idle control valve on drive by wire cars. With your foot off the gas it will still leave the throttle open about 2 degrees to keep the car idling.

Boost (PSI)[AP] or Manifold Relative Pressure(corrected)(PSI)[RR]

This displays the current boost pressure relative to current atmospheric pressure.
You would want this value to not go past the Boost pressure described by the maps notes.

Wastegate Duty (%)[AP] or Primary Wastegate Duty Cycle(%)

This is the current wastegate duty used by the ECU to achieve a target boost level. At 0% wastegate duty cycle the car will operate at wastegate boost.(7-9 PSI on WRX's) Wastegate duty cycle controls the amount of air that will pass through the boost control solenoid to the wastegate actuator. The wastegate actuator will open at a set PSI (7-9PSI on WRX's). The boost control solenoid limits the amount of boost that will be seen by the wastegate actuator. The higher the wastegate duty the less pressure is seen by the wastegate actuator. Higher wastegate duty's will result in higher pressure levels.

Turbo Dynamics (PSI)[AP] or Turbo Dynamics Integral (4-byte)*(%) & Turbo Dynamics Proportional (4-byte)*(%)[RR]

This displays the change in wastegate duty by the ECU to achieve a target boost level.

Air/Fuel Ratio (AFR)[AP] or A/F Sensor #1(AFR)[RR]

This displays the current AFR as measured from the front wideband oxygen sensor. It is normal to see readings around 14.7 AFR during idle and cruise. The AFR's will also climb to the 20's on deceleration because the injectors are shut off. The sensor is only accurate for determining AFR's during light throttle, cruise and idling. Because of it's location on the exhaust manifold, the exhaust gases become compressed as the turbo is spooled. The compressed exhaust gases cause the the sensor to read richer then actual AFR. The ECU does limit output of the oxygen sensor. Generally it will read down to the low 11's.

You need a wideband placed post turbo to measure actual AFR during WOT. If the stock oxygen sensor is reading AFR's above this lower limit at high boost levels it most likely running dangerously lean.

Inj. Pulse Width (ms)[AP] or Fuel Injector #1 Pulse Width(ms)[RR]

This is the current injector pulse width measured in milliseconds.

Inj. Duty Cycle (%)[AP] or Injector Duty Cycle(%)[RR]

This is the percentage of time during 2 revolutions of the engine that the fuel injector is open. It is calculated using engine speed and Injector Pulse Width. There has been lots of debate in the tuning community as to the accuracy of this value. Many tuners have seen fuel enrichment above 100% which is theoretically impossible. This has believed some to assume that the injector pulsewidth may not be accurately being converted from the raw ECU data.

What you need to know. If you are getting close to 100% or above in injector duty cycle your injectors are being about maxed out. This may be caused from the car running too rich or you are approaching the limits of your current fuel system.

Mass Airflow (g/s)[AP&RR]

This is the current amount of airflow going past the MAF sensor. It is pretty close to a measure of actual Wheel Horsepower. These numbers will vary with different stages and environmental conditions. If you have a boost leak it is likely that these numbers will appear to be much higher than normal. If you have a pre-turbo intake leak these numbers may be lower than normal.

MAF Voltage (V)[AP] or Mass Airflow Sensor Voltage(V)[RR]

This is the current Mass Air Flow sensor voltage. The voltage from the MAF determines the Mass Airflow (g/sec) along with other factors.
 
See less See more
#2 ·
#6 ·
the only problem with my log is that the dam is at 11 when it should be at 16, i have been working with cobb and they suggested it was a mechanical problem.
I was driving today and noticed on my ap that the DAM was at .188 for my entire drive. Next time I got in it was back to normal at 1 and has been ever since. I took a log at idle when this happened. Weird :confused:
 
#7 ·
yah im gonna try one more time to monitor the dam and if it does not go up ill take it to a mechanic. since i flashed it it has been pretty solid at an 11. its been about 50 miles since ive flashed it and i have been taking it easy. cobb said it could take 50-500 miles to get used to the tune. hopefully it goes up at least a little tomorrow.
 
#11 ·
like i said it is hard to get a good datalog around where i am cause its all mountain. still though, the fact is that the dam is too low and it either needs to learn the tune or i have a problem under the hood. the log i have posted is a 3rd gear wot pull to about 4800 rpm, its the best i could do with the road i had, eventually i will get a better log when i find some decent road. oh and btw i can tell u it is a REAL cobb stage 1 93 oct tune i assure u. i suspect i have a mechanical problem due to the lag and the dam not "learning" fast enough. if u cant help dont post.
 
#13 ·
Touche young padawan..... I can in fact help you. But throwing that log up on several threads will not change anything.

I helped in the last thread... and you continue to throw that shit up.

Buck up and get a real log or jump on a dyno.

As far as logging at idle, I haven't a clue. A 3rd gear log is short as it is. Need to see the AFR's during the entire WOT 3rd gear pull from 2800ish - close to redline.
 
#18 · (Edited)
Drop in boost on Stage 2+ Protuned 2011

Recently I noticed a pretty decent lack of power upon WOT. I have a 2011 WRX with the following mods:
Cobb Intake with Box
Cobb DP catted
Tsudo Cat Back Exhaust
Process West TMIC
Go Fast Bits Respons BOV
Grimmspeed Up-pipe
Tial 44mm EWG plumbed back into DP
Grimmspeed EBCS
Grimmspeed Adjustable Wastegate Bracket
Cobb Accessport V3
Stage 2+ Protune by PIA in Tacoma, WA (310whp, 349tq @ 20psi)

I have a before and after datalog. I'm seeing drops in PSI, WG duty and it's running lean under load.

Before:
https://docs.google.com/spreadsheets/d/162sZaS-bNuUeaBTDftTQ-RFpOgfImwYwa2Ci7DT399Y/edit?usp=sharing

After:
https://docs.google.com/spreadsheets/d/1iH9zCpgGa_Q1j7Lg1feuSlMsCKvcvLctd6HLQNCuOK4/edit?usp=sharing


Does any have any thoughts on what might be causing this? I've checked for boost leaks and none were found.
 
#19 ·
@ElJefe - typically logs are recorded at 100% throttle in 3rd or 4th gear ( depending on if you have a 5MT of 6MT ) and from 2500-6500 RPM.

If you can grab us that snapshot we can help you figure out whats off. Otherwise we dont have quite enough information to really be of assistance. Without a complete log I would start with a boost leak test. You have lots of connections from the turbo into the throttle body that are aftermarket, tighten those down and clean your MAF and see how that works.

hope that helps
 
#20 ·
#21 ·
Im not a professional tuner but from many a conversation with Paul @yimisport and Eric at Torqued performance some FKL and FBK are to be expected as the vehicle is moving. The sensors are very sensitive and any noise outside the norm will be picked up. The thing to look out for is when FBK of FKL don't immediately taper back to 0 or if they cause changes in other columns and come back. When the ECU sees those numbers as a problem it will adjust your dynamic advance multiplier to compensate. Your DAM appears to still be 1 so it doesn't look like your ecu is holding you back from the FBK or FKL.

Id really like to see your waste gate duty cycle and your injector duty cycle to see if maybe your waste gate is stuck partially open, or you might have an injector thats not clogged or malfunctioning. ( im not thinking clogged injector because your AFR seems normal, granted its not a wideband but the ECU seems happy with the AFR its receiving )

The other things to look for before you go take another log is boost leaks. Check all the hoses and fittings on the high pressure side of the turbo sometimes the throttle body to intecooler piping will slide off or crack and cause all kinds of headaches. The process west intercooler has a turbo flange that connects to a silicone pipe right? double check that connection and be sure all your clamps are tight. If they are check that all your vacuum lines are in their proper place as well. You can use soapy water to test for vacuum leaks or take it toa shop to have it smoke tested.

Absolute worst case you might have a malfunctioning wastage actuator, stuck arm or fnky boost controller ( honestly an EBCS should be on your mods list after stage 2 anyways )

hope that helps
 
#22 · (Edited)
Thanks for the advice and clarification on FBK and FLK! The data log does show the wastegate duty, it's the very last column. Not sure if that's what you're looking for or not.

Someone on Nasioc was concerned that the overboost was going so high. On the latest data log it hit 18, the previous logs were in the 20's. Is that something to be concerned about.


I forgot to put it on my mod list but I do have the Grimmspeed EBCS. I also have their adjustable wastegate bracket to keep the factory wastegate closed, my tuner recommended this.

I'll double check all the high pressure tubes and vacuum lines again tonight.
 
#23 ·
Im sorry my tablet had that cut off,

Looking at your log Im not seeing boost pressures in the 18PSI range. Max I see on your log is 12.08 @7.167 looking at just that row your wastegate is set to 53% I would expect the wastegate up much higher than that to hold the gate closed and build more boost. Im currently running the stock controller but my wastegate duty cycle on a Torqued Performance Stage 2 is up around 85% tapering down to 75% at 6500RPM. If you have other logs that show you hitting higher boost we can look at those but "datalog5" looks like pretty bad under boost.

The tune would be different for aftermarket EBCS and I dont know off the top of my head what values to look for with the grim speed unit in particular. Hopefully one of the guys can chime in with the expected values.
 
#24 ·
On the "before" log that I posted originally I was hitting 16.48 at WOT and wastegate duty was still low around 52%. That's the only log I have from after the tune before this started happening.

I've been running this tune for 4 months with no weird problems like this. I had a couple times where the IC hose slipped off the throttle body a little and one of the BOV vacuum hoses kept popping off the intake manifold nipple. When those happened the boost leak was really noticeable and I couldn't seem to produce any boost, the car would stutter over 2750RPM and 40% throttle and the turbo sounded way off. I've since gotten those connections to stay on nice and tight. What's going on now doesn't feel the same at all since I'm still able to produce about half my target boost and I still haven't been able to find any boost leaks. I tried the soapy water method last night on all positive pressure connections and still nothing.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top