All, Primetime,
I’m going to do some logging, finally, tonight. I have the wireless VCDS transmitter for Apple computers. However, it simply doesn’t log fast enough so I use the cable and bought a small windows computer. The number of choices for logging, in my menu, are almost endless and not well defined. Would someone be kind enough to to give me the menu numbers for each item as well as the name of the item I should be logging? I.E., my box, Timing-49, knock sensor-291 etc.
Thanks much.
Sky,
This was posted by Primetime in the performance expectation thread a while back. I think this is what you need.
Vag-com Data Logging Basics:
The vag-com tool IMO is a must have for anyone who is serious about understanding their cars performance… Below is a quick reference on some of the key fields and how to get started on logging. I prefer to do this at the dragstrip while making passes but also log on the street as well… The beit of the dragstrip is you can go through 4+ gears and get lots of data points. Here are the basics…
When you login choose the following —> engine controller button —> advanced measuring values ----> then you’ll need to choose the various fields you want to log. You can log up to 12 but the sample rate is slower the more you choose however it is still decent even with 12 so log what you want… A very key step that I’ll mention now and later is to choose “Turbo Mode” and also check off the box in the upper left called “Group UDS requests” This will give you the best possible sampling rate… If you don’t do either of these the sampling will be very poor so again, it’s critical…
Now for fields… When you first log on look for ambient air pressure and select that… Write down the value and then de-select… You’ll use this later to convert your hPa boost number to psi if you desire and I’ll go over that… Here are the fields I then select while logging… Again, the # of the field may be different but the names shouldn’t change.
I can’t copy a table from excel in so I’ll just do a written listing: Note the names usually don’t change but the field #'s do with vag com revisions… I’ll try to update as new versions come out but these should be the latest…
Field Name: Field #: Notes:
Accelerator Position 3 This will tell when you are WOT and usually the highest value is 94
Ambient Pressure 7 This is the current pressure, just check this before logging and write down, don’t log it
Charge Air Pressure Specified 10 This is the requested boost in hPa, you’ll need to convert to psi
Engine Speed 19 This is your RPM value
Ignition Angle; Actual 180 This is the requested timing your car is asking for or actual if no retard is occuring
Intake Air Temperature 182 This is the IAT your car is seeing in celsius
Intake Manifold Pressure; Absolute 184 This is the boost your car is seeing in hPa, you;ll need to convert to psi
IGA_AD_1_KNK[0] 415 This is timing retard, just pick two for logging
IGA_AD_1_KNK[1] 416 This is timing retard, just pick two for logging
IGA_AD_1_KNK[2] 417 This is timing retard, just pick two for logging
IGA_AD_1_KNK[3] 418 This is timing retard, just pick two for logging
IGA_AD_1_KNK[4] 419 This is timing retard, just pick two for logging
IGA_AD_1_KNK[5] 420 This is timing retard, just pick two for logging
Air Mass 476 This is how much air flow you are pulling in or your MAF value
RFP_AV 535 This is how much boost you are bypassing expressed as a percentage of the total
There are many other fields and we can add more as we go but these are the basics that will tell how the car is performing for the most part. As we move forward we can discuss how to read them, understand them, and know about what you should be seeing if the car is performing as it should be…
Most of the fields are straight forward… accelerator position shows when you are WOT, engine speed is rpm, IGA_AD_KNK are the individual cylinder timing retard values so you can see if timing is being pulled, Ignition angle is your total timing, Air Mass is the volume of air going into the blower, intake manifold pressure is your boost levels in hPa, RFP_AV is your boost bypass valve stated in percent, Intake air temp. is the temp of the intake air, and charge air pressure specified is how much boost the tune is calling for and this is your upper limit so to say… There are many other fields we can go over but these are where you should start and will tell you a ton about the car…
For converting the hPa #'s to psi you take the hPa value and subtract the ambient value you wrote down from it and then multiple that value by .014503774 This is than your boost in psi.
What I do at the track is get everything setup and then I just have to hit start right before I make a pass and then stop right after the pass… Whatever, you do DON’T shut the car down w/o first saving the file otherwise you can potentially lose the file… I usually make a few passes in a row save the file, let the car cool down and repeat. It really depends on how crowded the track is or isn’t…
Again, make sure to hit the turbo button and check of the group uds requests box as it’s critical and easy to forget…
I’ve tried logging in the past and it simply hasn’t worked. I don’t have a “turbo” mode in my VCDS, it’s a new model? Regardless, thanks much. will try tonite.
For logging start small pick one set of blocks like say 003 (not sure if this is the same on the B8 but block 003) is throttle and if you do it in blocks you can get maf throttle rpm and ignition. But if your just picking one value to look at pick say 3. Then without the car moving or even logging watch the values live while your in neutral. This will help you get an idea on what your looking at. Then go through some of the other blocks and do the same. When it’s time to log you should have more of an idea on what’s going on. When you fill out the blocks to log there should be a box at the top that says turbo. Click that and it will give you faster samples
OK, thanks again.
Anytime this forum is here to be different. No question or skill level should be not helped. The one thing I forgot to add is when your looking at the blocks in neutral try giving the car gas you will almost always see values change. Correction values won’t change or shouldn’t change as there is no load to offset.
Logging can be fun and exploring all at the same time. The only thing about logging is some people try to live in logs and only logs (cough b5 guys) logs are only a small snap shot. Logs can tell you if your car is healthy and tell you if the car should perform as expected. Funny enough the B8 guys know more in just a few years about how logs work and what to look for then b5 guys. And that’s because when you look at logs and understand them you have to be honest about what you see. Understanding what your logging helps you be a bigger part of your car.
Well, no logging tonight. My VCDS sucks. Built for wireless and Mac computers. I have no “turbo button”. As soon as I turn it on I have to endure an hour of damned updates. I appreciate your numbers but mine are different and my choices seem endless. Will try again tomorrow night.
shocking
just go to the track and run something
It seems everything I write shocks you!
Advice from a guy that posts his license plate on the internet?
lol yeah it’s not like it’s seen by LITERALLY EVERYONE when you’re on the road.
I guess that means you post yours on the net too?
Well I don’t go out of my way to make sure it’s not if that’s what you mean.
100s, if not 1000s of people see your license plate every single day. What does it matter if it accidentally ends up online?
Sax…ON?
Good point but the WHOLE WORLD can see it on the net. Having had my identity stolen once was enough. Posting a license plate makes the act even easier!
Come on Saki, we know you can give more grief than that!
What is your dilemma with this?
Do you have the Ross-tech Hex-Net?
The license place thing is beyond retarded…
Search for my thread on Audizine. It covers everything in detail and step-by-step. Just search for threads started by me…
Do any of you have the wireless for Apple computer only VCDS? That is my problem!