I suggested over the past few months that we start a performance expectations thread. This way if you buy a new or new used B8 3.0t and decide to modify the car, you can have some idea on what your expected performance should be per your mods.
I think the best thing to do here is to keep with the two biggest companies and their results for the averages. Those will be the results from APR and the AWE - GIAC cars. Both APR and AWE have had tunes out for the longest and have had the biggest amount of safe success
Right now we have:
Stage 1: Stage 1 starts with as little as just a tune and can grow to as large as; a tune, intake and exhaust.
Stage 2: Stage 2 starts with as little as a tune and a smaller pulley and grows from there.
The configurations are:
2010-2012
2013+ cars have some differences that would effect performance.
2013+ differences:
The biggest differences come from the transmissions having different gear ratios and that after 2012, the shifting RPM’s on the B8 S4s dropped from shifting at 7000rpm in all gears to now shifting at 5800rpm from 1st to 2nd and then shifting at ~6300rpm from 2nd to 3rd and from 3rd to 4th and so on.
While the finial gear ratio is the same, the independent ratio per gear is different. This is also just in the DSG configuration. The manual cars are exactly the same from 2010 till current.
I suggested over the past few months that we start a performance expectations thread. This way if you buy a new or new used B8 3.0t and decide to modify the car, you can have some idea on what your expected performance should be per your mods.
I think the best thing to do here is to keep with the two biggest companies and their results for the averages. Those will be the results from APR and the AWE - GIAC cars. Both APR and AWE have had tunes out for the longest and have had the biggest amount of safe success
Right now we have:
Stage 1: Stage 1 starts with as little as just a tune and can grow to as large as; a tune, intake and exhaust.
Stage 2: Stage 2 starts with as little as a tune and a smaller pulley and grows from there.
The configurations are
2010-2012
2013+ cars seem to have some differences that would effect performance.
I think you need to separate the B8.5’s from the B8’s, especially the DSG’s with the different gearing and factory trans software. The GIAC DSG tune levels the playing field, but if the expectations are to be realistic, I’d recommend separating B8 from B8.5.
Part of the problem with the 2014’s is we don’t have anyone running the GIAC DSG + ECU flash well. I don’t think that psugold guy should be the benchmark. At minimum, we need someone who is competent enough to purchase a vagcom cable and self diagnose via logging, and at least be able to communicate with Ron or others who know how to interpret the results relative to platform expectations.
Adding the separation in per year per issues. I don’t know what makes the B8.5 cars slower but those have said the transmission and gearing. This might be a good thread to list the year to year differences and how that effects performance.
The facelift DSG cars ARE slower without a tcu tune though aren’t they? Spinning the engine to only 6200 means the supercharger is nowhere near peak output. Rpms are your friend. A 6200 rpm red line is like leaving the bypass valve open.
And the 14 cars are from forum banter slower, but in reality we have only had testing done in dogshit conditions so it’s virtually impossible to judge.
They are slower and you nailed one of the major reasons why.
Each gear shift is happening roughly 1000 RPM sooner. That means you’re averaging lower horsepower in each gear compared to someone revving higher and because of that, times and trap speed suffer.
Auditude,
Did your father’s DSG have DSG software enabling a higher max RPM?
Did your father get this time and trap on 93 octane?
I’m not looking to “call you out,” but knowing those two variables will help quite a bit in this expectation thread.
Hyden, 10-12s shift at 7k if performing as they should… 13-14s shift earlier and have taller gears on the dsg cars… I’ve seen 3-4 sets of logs with cars that don’t have dsg tune and all the 1-2 shirt were 5800 and the 2-3 3-4 were 6200-6400… Leaves lots on the table but if you ask the expert roger federer it doesn’t hurt performance much because of all the tq… Lol. Yet more bs that dude spews…
I’m not sure it’s as simple as peak power. I believe you have to look at the thrust curves and make that conclusion differently for 1-2, 2-3, 3-4 etc.
Dparm plotted them out on an AZ thread. Here they are. Would be cool if Arin or someone could provide the matlab data for tq/hp vs RPM for a dyno run, that way we could plot similar curves for stock, stage 1, stage 2. Then we could tell the effects of short shifting based on the intersection of these lines. My pretty obvious hypothesis is that you should redline the car every time when tuned because of the added TQ up top, and relatively large change in gear ratios when accelerating 0-100 mph.
Here is his quoted post:
[quote]There’s such a thing as a thrust curve, which I wrote about in the B6/B7 S4 forum. It relates gearing with powerband location and size.
Thrust = (Engine Torque x Gear Reduction x Final Drive Reduction) / (Wheel Diameter / 2)
You graph thrust on the Y-axis and speed on the X-axis. What you’re looking for is how well the lines come close to meeting each other. It’s an effective way of showing how well the gears are setup for the car’s powerband size (width) and location (RPM range). Also helps you determine optimal shift points.
I generated thrust curves for the B8 and B8.5 S4. This is a stock motor with 25% drivetrain loss on the stock 19" wheels/tires.
For the 1-2 shift, go to redline on both cars.
For the 2-3 shift, go to redline on both cars.
For the 3-4 shift, short shift on the B8. Redline the B8.5.
The 1-2 shift is always violent because of that gap in the curves – there’s a big change in the amount of thrust we generate.
I actually did one for the Stasis tune (B8 only, of course). We obviously generate more thrust in every gear but the S tronic gearing is not optimal for the new powerband location and size, as evidenced by the gaps between the curves. That means you would want to redline every gear.
So… We would like to build this thread into the best place to get information on the B8/B8.5 S4… We’re going to create some sections with content on vagcom mods, logging, error codes, a section on modifications for the car, a drag race section, etc. Basically, looking for input from the other members and people who want to contribute… I’ve offered CV to start with some of the above… I’ll try to dedicate some time to it each day or as I get free time and anyone else please feel free to do the same… Let’s make a post and then let CV add it to the first post via an edit and then either leave it in your post or remove it…
I’ll start…
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…
Performance Modifications: Air Intakes/Intake Tract: There are basically two types of air intakes, an open element and boxed one. Basically, an intake helps route air to the blower on our cars. The open element basically has the filter open in the engine bay and the boxed one either reuses the stock airbox or comes as an after market box that is similar to the stock box. The stock intake is decent but restrictive and improvements are made with an after market intake. These values can be measured with a vag com cable and by logging block 476 “Air Mass” The higher the number the better obviously.
Open element - Roc-Euro, USP, etc.
Boxed - APR(Cabrino), AWE, Eurocode, etc.
From the testing that I and others have done it has been proven that the open element ones provide more airflow to the blower which is critical in making boost and power. My logging via vag com has shown that these open element intakes provide upwards of 10% increase in airflow which is huge when running a PD blower like our cars do. At the track we are talking about gaining .1-.15 improvement in the 1/4 mile which is again huge. Many folks have speculated that these types will suck in more hot air since they aren’t sealed off from the engine bay, but that is a misconception as the blower sucks a ton of air and once your moving the air from the engine bay is evacuated and you are sucking in air from outside the car. I’ve found to keep the intake temps down you can use some basic header wrap to wrap the intake pipe which through testing I’ve shows it reduces the surface temp of the intake by 15-20 degrees F. Again, this is huge because it’s all about getting as much cool air into the blower as possible. Of course ambient conditions impact this as well but in all cases the open intakes seem to flow better and run just as cool so to say.
Throttle Bodies are another area of opportunity but unfortunately there are none available that utilize our current wiring harness configuration. I worked with a few companies to try to solve this and I know APR now has a solution with their pending release of the new Eaton TVS 1.74L blower upgrade. After taking the TB off we noticed that the intake tract of the cast manifold was very tight and would be a restriction as well, if it isn’t already so with the inability to get a pigtail to make the electronics work I abandoned the idea of upgrading to a bigger one. For reference the stock one is 70MM which is fairly small in my experience with PD blowers and most of the Cobra, GT500, Camaro, Vette owners who have TVS/PD blower cars upgrade to much larger and get nice benefits. Here is a link to some pictures if you are interested…
Blower porting is another potential for increased power but after discussing with Stiegmeir I didn’t go this route either but I’ll probably tear apart the stock blower in the near future and should be able to provide a some pictures and a better perspective on if it is worth it or not. If so this would be a fairly cheap way to gain some additional boost, similar to what many of the Cobra, Camaro, Vette guys do…
Please feel free to add any more details and I’m sure CV will gladly update into the first post and I’ll do the same if I think of more…
I found this alignment info for the B8. Not sure if they changed the spec for the B8.5…
2011 Audi S4 Quattro (B8)
1BD Suspension
Primary Wheel Alignment Specifications
Left Side FRONT Right Side
Caster is not specified CASTER Caster is not specified
Cross Caster is not specified
-1.08° ± 0.38° CAMBER -1.08° ± 0.38°
Cross Camber: 0.00° ± 0.50°
TOTAL TOE
0.33° ± 0.17°
0.17" ± 0.08"
Left Side REAR Right Side
-1.33° ± 0.42° CAMBER -1.33° ± 0.42°
TOTAL TOE
0.33° ± 0.17°
0.17" ± 0.08"
Thrust Angle: 0.00º ± 0.17º
Additional Specifications
Recommended Alignment Procedure: 4 WHEEL
Turning Angle (Inside/Outside): 20.00º/18.18º ± 0.50º
Ball Joint Testing:
Testing Method: Type H
Upper Ball Joint AXIAL Tol: No visible movement.
Upper Ball Joint RADIAL Tol: No visible movement.
Lower Ball Joint AXIAL Tol: No visible movement.
Lower Ball Joint RADIAL Tol: No visible movement.
Lugnut Torque: 89 ft.lbs.
Exhausts:
The S4 exhaust essentially consists of 4 components the exhaust manifold, the catted pipe, downpipes, and catback… Below is a good link to APR’s website that shows the various parts for reference. Overall, the S4 exhaust system seems to flow fairly well and there isn’t a lot of performance to be unlocked. However, the sound of the stock exhaust does leave a lot to be desired. The B8.5 also comes with a “soundakator” which pumps in fake exhaust sounds into the cabin, however many disconnect it.
Exhaust manifold, this is the part that connects to the motor and where the exhaust gasses first enter, it seems they perform adequately. The only way to replace these is to go with the Eurocode headers which replace both this section and the catted pipe. Based on drag racing results the headers offer very little performance gain over stock and are probably no better than the 034 HFC’s or test pipes. GMG also makes headers for these cars however, when they were attempted to be installed they didn’t fit! Headers are also very labor intensive from an install standpoint as the motor needs to be removed or lowered in order to get the stock ones out and headers in.
Catted pipe, these are the catalytic converter pipe portion of the exhaust. The catalytic converters are huge on this car but seem to flow well. The only company that I am aware of that has or does offer a HFC is 034 motorsports. There was some debate early on as to their performance benefit. I do think they improve flow a little but at the current stage II power levels they are probably not neccesary. They do improve sound and make the car much more audible. 034 also offers a cat less pipe or test pipe and these seem to improve performance over both stock and HFC’s but minimally at best. It is to be noted that the current fastest stage II car runs these test pipes. Obviously, many states have emission laws which make these illegal. I have passed the ODB testing in Ohio with the 034 HFC pipes. Similar to the headers the install is very labor intensive.
Downpipes, these pipes connect to the catted pipes and have a flex joint and small resonator. There really is no performance benefit to replacing these and most buy aftermarket for sound. There are both resonated and non resonated downpipes from suppliers like AWE, Miltek, etc. Downpipes can usually be purchased separately but some company’s like APR require you to buy the full downpipe and catback system.
Catback, this is the last piece in the exhaust and the stock setup consists of 3 mufflers that are connected to the downpipes with one in the center of the car and two near the rear tailpipes. This section along with the downpipes is what 95% of the aftermarket suppliers offer and what most people replace especially given the labor involved in the other sections. Again, performance gains are minimal at best at least on stage II power levels and most do this modification for sound. There is a secondary benefit if you go with the non resonated setup as for example the Miltek eliminates the rear mufflers which cuts about 15lbs of weight. AWE offers a similar option as well… APR is limited to the one offering that retains three mufflers.
Most of the decision will come down to sound and/or brand loyalty. The prices on exhausts have risen substantially over the past few years and makes it a costly mod with very little payback again outside the sound improvement. So not the best bang for the buck. As the platform moves forward with stage III offerings and increased boost levels we may see the exhaust systems become more of a requirement but that is yet to be determined. There are literally 100’s of videos of various exhaust combinations on line if you search so I won’t post a bunch of clips here.
Tunes:
The most controversial concept when it comes to the 3.0T motor is tuning and who’s to run. The 3.0T motor is being used by Audi in several different platforms with several different HP/TQ ratings and has proven to be fairly tune/tuner friendly. There are several companies that currently offer ECU flashes for the S4 3.0T along with some of the other vehicles that use the same motor. There are also some who offer “piggy back” solutions however; those have for the most part been proven to be ineffective.
Piggy backs - MTM, ABT, etc
Flashes - APR, GIAC, Revo, ASP, EPL, etc.
A piggy back takes signals from your sensors and modifies them to trick your ecu into reading a different value for boost, a/f, timing, etc. They have worked well on some platforms but again have been proven to be ineffective on the 3.0T and it’s relatively advanced ecu.
A ecu flash basically modifies maps within the ecu to improve performance via increased timing, leaned out a/f ratios, increased boost, throttle control, improved duty cycles, cam timing, etc. The stock maps are modified or overlaid with different maps that impact or change the above. Most ecu’s have 1000’s of maps but usually only some are modified and often just parts of the maps are changed. Cars are tuned from the factory for a specific performance level, mpg level, and emissions results which often leads to power being left on the table. FI engines traditionally respond to tuning better than NA motors but that’s not to say NA motors can’t get more power out of a tune it’s just usually less and from what I understand harder in some cases.
Early on there was much debate on how the car got “flashed”… APR initially required you to send them your ecu and later allowed tuning through their dealer network but still required the ecu to be removed from the car. Over time they and others have figured out how to flash the ecu through the odb port and no longer require removal of the ecu. To some this is important but to others it isn’t. Personally I feel more comfortable pulling the ecu and sending it to APR and that is the route I still use for testing and updates.
For the 3.0T there are really two maybe three main tuners at this point. APR, GIAC and Revo, as I’ve mentioned above there are others like EPL, ASP, AMD, etc but their results for the most part are unknown since only a few choose to run them and unfortunately they usually don’t share the results, think Saxoff for EPL or that old dude bp for ASP… I’ve seen hundreds of data logs from APR, GIAC, Revo, Stasis(APR/Revo) but have yet to review a log from the others…
So what gets changed by the tuners on these motors? It’s basically the things I’ve mentioned above.
Boost levels – The boost is bled on these motors stock above 5000 or so RPM’s which causes the car to not make optimal power. By just allowing this boost flow into the motor will make additional power all the way to redline. There may be some increase at lower RPM’s but most of the boost increase I’ve seen in the lower RPM’s is a result of putting a pulley on the blower so that the blower spins faster and boost comes on sooner. Keep in mind this car uses a PD blower so boost is more linear then a centrifugal blower which is more RPM dependent.
Timing – Timing basically determines when the explosion in the cylinder happens, obviously that’s a simplistic statement but for this discussion will work. More timing is usually better to a certain extent as there is a limit to its effectiveness before detonation will occur and potential engine damage or power reduction, think early Revo tunes. They ran very high timing by requesting it and disabling the upper limit safeguards which caused a few blown motors. IMO APR/GIAC are fairly conservative when it comes to timing as I think everyone would rather have a pretty fast car that is safe vs a fast car that is one pass away from potentially grenading the motor.
Cam timing – This has more to do with the physical parts associated with the various cycles the car goes through like the pistons and valves. These are usually controlled via a timing chain or belt. I’m honestly not sure how much these are modified on our cars by the various tuners?
RPM limit/redline – These cars seem to continue to make power past the stock redline of 7000RPM on the B8 or 6300 on the B8.5 so the tunes often allow the limit to be raised to 7200RPM’s. However, on the DSG cars to take advantage of this you need a DSG tune which currently only GIAC offers. 6-speed cars can take advantage of this w/o modification to the transmission.
A/F ratios – This is basically the ratio of air to fuel that is entering the cylinder. You’ll often hear the terms running lean or running rich. Lean is too much air and not enough fuel and vice versa for rich. Our cars are direct injection(DI) so they can get away with a leaner mixture and also have a higher compression ratio but there is still a limit. The tunes we are running lean the car out slightly which helps increase power levels and in some cases fuel economy.
Duty cycles – These are more like when a fan comes on, when a pump comes on, etc. I know that the tuners change these in order to keep temps reduced.
There are differences between the B8 3.0T(2010-2012) and B8.5(2013- +) There also appears to be some differences between the 2013 and 2014 tunes which has become evident recently given the lack of performance from the tuned 2014’s.
APR – These guys have been in the business along time and were the first to be able to properly tune the 3.0T motor and thus got lots of market share early. Their results speak for themselves as they currently have the fastest B8 S4 and dominate the ¼ mile list. They offer 91, 93, 100, and 104 octane tunes with switchable programming via the cruise control stock. Their tune has evolved over the last few years with different versions that have improved upon the results. I don’t think any buddy has taken them up but I believe they would offer a “custom” tune if you went directly to them and paid for their time however, I’m not sure this would be a benefit unless they were going to tune for running meth or nitrous.
GIAC – These guys are like APR in the sense that they have been tuning for a long time, they came to market a little later than APR and thus lost market share. Their tune performs very similar to APR’s with ¼ times very close to APR’s and probably results are more based on conditions and such. GIAC also offers a DSG tune which changes some things and allows DSG cars to take advantage of 200 additional RPM’s however, I’m not sold on the value of their DSG tune but that’s more just opinion based on results I have seen. IMO you can’t go wrong with GIAC or APR and it’s more a matter of availability and choice than it is with performance.
Revo – These guys seem to be bigger in Europe and I believe were second to market. However, this caused some issues as it seems they rushed their tune to market which resulted in some short cuts and blown motors. It seems based on logs that they have subsequently “fixed” their tune and it now looks to perform better and more importantly safer.
Others – EPL, AMD, ASP, etc. Haven’t seen many results… Unfortunately, mostly rhetoric from their outspoken customers who talk big but won’t share anything and have mediocre results is all we’ve seen. In some cases(ASP) they got so scared when results were requested they basically exited the market instead of showing what the tune was doing. EPL has recently joined forces with Alpha/AMS so this may help them but I think in the long run if AMS is smart they will tune internally or they may get a bad reputation based on the mediocre results. Time will tell…
Hopefully, CV can chime in on this section and correct any information that I have misstated or further explain how tunes work as my explanations are fairly simplistic and general as it’s much more complex than I have stated. Also, anyone else can correct anything or feel free to add to my basic review…
Below is the “logging for dummies” version I did for some people on Vendorzine. A lot of it is what Ron already covered, and probably covers a lot of the same things (I did learn most of this from him, so…).
Several people have asked about logging the their vehicle, so I have put together a “how to” on logging with the Ross-Tech VCDS below (VAGCOM). Logging is critical to understand how your car is performing, and even more so if you are tuned. There are several parameters that can be logged that will give a good indication as to how your car is running. It may not always tell you what is causing a problem, but it will tell you if there is a problem. This “how to” guide will cover how to perform basic performance logging, and also how to interpret some of the results (in the next post).
First, a few things to note:
Every version of Ross-Tech software is slightly different. In terms of logging, the only real difference is the group/location number associated with each logging parameter. The name of the parameter will be similar from version to version, but the associated group/location number may be different. I am using version 12.12.2, but yours may be different.
One of the key things people like to log is requested and actual boost. In recent versions of the Ross-Tech software boost is not displayed as an absolute value. Some conversion and calculation is required. This is covered in the next post.
While there are others ways to log a vehicle, this only covers using the full version of Ross-Tech software with their VCDS cable.
Logging must be done with Windows software. That can be XP, Vista, Windows 7 or 8. Doesn’t really matter. An Apple/Mac that runs Windows will also work (Boot Camp, Parallel, etc.)
Getting Started
Step 1: Plug the Ross-Tech VCDS cable into the OBDII port under the dash on the driver’s side.
Check for Fault Codes
Step 3: Before you start logging, ensure there are no fault codes. Press the “Auto-Scan” button on the VCDS main menu.
Step 4: Once in the Auto-Scan section, press the “Start” button to scan for codes. The scan will take a few minutes as it scans all modules. If there are faults, I would recommend saving the scan results (copy/paste, save, print), and then clear the faults with the “Clear all DTC’s” button. Once this is done, “Close” the Auto-Scan section, and return to the main menu.
http://i570.photobucket.com/albums/ss146/jran76/VCDSautoscan_zps2e94133c.jpg
Step 9: Select the parameters you would like to log from the list.
Notes:
–VCDS will let you select a maximum of 12 parameters, or 10 parameters if you use grouping (which is a must for good logs as we’ll cover below). So, you really need to concentrate on the parameters that are most important for this particular logging session.
–For general performance logging, I recommend the following parameters: Group/Location Number- Parameter Field (details)
002- Accelerator position in %
009- Charge air pressure specified value in hPa (specified boost+ambient air pressure)
018- Engine speed in RPM
089- Air mass in kg/h
186- Ignition angle; actual in degrees
188- Intake air temperature in degrees C
190- Intake manifold pressure; absolute in hPa (actual boost+ambient air pressure)
418- IGA_AD_KNK[0] in degrees (timing pulled on cylinder 1 due to knock detection)- Just pick 2 Cylinders to log
419- IGA_AD_KNK[1] in degrees (timing pulled on cylinder 2 due to knock detection)- Just pick 2 Cylinders to log
420- IGA_AD_KNK[2] in degrees (timing pulled on cylinder 3 due to knock detection)- Just pick 2 Cylinders to log
421- IGA_AD_KNK[3] in degrees (timing pulled on cylinder 4 due to knock detection)- Just pick 2 Cylinders to log
422- IGA_AD_KNK[4] in degrees (timing pulled on cylinder 5 due to knock detection)- Just pick 2 Cylinders to log
423- IGA_AD_KNK[5] in degrees (timing pulled on cylinder 6 due to knock detection)- Just pick 2 Cylinders to log
540- RFP_AV (bypass valve percentage)
http://i570.photobucket.com/albums/ss146/jran76/VCDSloggingfields_zps77230125.jpg
Step 11: This is very important for getting good logs…. Press the “Turbo” button, and check the “Group UDS requests” box. This will speed up the logging, and also group all 10 fields to the same timestamp. This is the only way to get useful logs (otherwise, each parameter will have a different timestamp).
http://i570.photobucket.com/albums/ss146/jran76/VCDSlog_zps04769222.jpg
Step 12: Once the logging parameters are setup, press the “Log” button to initiate the logging session. Note: This will not start the actual logging.
Step 13: Once your car is running, and you are ready to log, press the “Start” button. This will start the actual logging process.
Notes:
–Logging should be performed in a controlled area where you can safely reach 90 MPH. The drag strip or dyno or the best option, but in places like Texas there are some pretty safe places to do this on the road (I do it late at night in traffic free areas with 70+ MPH speed limits).
–Logging runs should capture a full 3rd gear pull at a minimum. 4th is probably a little better, but that should only be done at the drag strip or on a dyno. A full pull is around 3000 RPM to 7000 RPM. This can be tricky on a DSG car because you need to avoid triggering the kickdown switch at lower RPM’s. Play around with what works best, but the sooner you can get to pull acceleration the better.
–When logging, the A/C and radio should be off, windows up, car in dynamic mode if available, and traction/ASR off (hold traction button for at least 5 seconds to turn both off).
–Logging should be done on a flat surface, and if done multiple times it should be done at the same location, and in similar conditions if possible. This makes comparing data more accurate.
http://i570.photobucket.com/albums/ss146/jran76/VCDSlogstart_zpsb7d252fc.jpg
Step 14: Once you have captured the needed logs, press the “Stop” button to stop the logging, and “Done, and close” when finished. The logs will be saved to the Ross-Tech/VCDS/Logs folder (typically on the C:/ or wherever the Ross-Tech software is installed) as a .CSV file. It can be opened with Excel or similar.
http://i570.photobucket.com/albums/ss146/jran76/VCDSlogstop_zps68e72dfe.jpg
That is it for capturing basic performance logging. The next post will cover some of the basics in regards to interpreting the logs.
In addition to logging the basic performance parameters listed above, VCDS gives the option to log many many other things.
Some examples:
–If you are experiencing timing pull due to engine knock detection, you may want to log the timing being pulled on each individual cylinder instead of just the 2 covered above. In that case you would want to log: accelerator position, engine speed, ignition angle; actual, and IGA_AD_KNK[x] on all 6 cylinders. Those 9 parameters may point to an issue with a specific cylinder.
–If you are experiencing misfires, you may want to log misfires on all 6 cylinders to see where the problem is coming from. Note that some random misfires that DO NOT result in a fault code are fairly normal. In that case you would want to log accelerator position, engine speed, misfires all cylinders, misfires cylinder x on all 6 cylinders. These 9 parameters may point to an issue with a specific cylinder.
–As you can see, accelerator position and engine speed are really needed every time so you have some reference point in the logs. Intake air temperature is also good to log as it will give a good idea on the conditions.
