How to figure out if you have an ECU flash/tune already...

[dWiGhT]

I recently bought an RS6 from a dealer so I have limited history and no access to it.

There already are a couple of upgrades on the car: Miltek exhaust, EvolutionMotorsports diverter valves, coilovers. Given all that has been done already I find it hard to believe that it hasn't been flashed/tuned.

I tried the APR trick that switches programs but it didn't work so the tune couldn't be an APR one. (or I'm doing it incorrectly)

The reason I ask is that I've had an DTC popup (16985) that seems to be related to chipped ECUs... with the APR being the one that has it. I cleared the code and haven't seen it again...

dWiGhT

[V8weight]

Yeah, the 16985 is the check sum error, which would indicate that the ecu has been flashed with new software, or the ecu is bad. You could log block 115 to check actual vs. requested boost to confirm that the car is flashed, but there is no way to determine by whom. Stock requested boost should be in the 1650mb range, while a tuned car should be requesting somewhere around 1950mb.

[dWiGhT]

Just did a log and got lines like this...

...
5280rpm 160.2 load request: 1910.0 actual: 1820.0
...

so now I need to figure out which it is... still digging history on it.

dWiGhT

[dWiGhT]

Just did a log and got lines like this...

...
5280rpm 160.2 load request: 1910.0 actual: 1820.0
...

so now I need to figure out which it is... still digging history on it.

dWiGhT


So converting 1850 mbar to psi is like 28psi... really? wow...

dWiGhT

[DHall1]

Not 28psi

Check your calcs again Einstein. j/k

You do have a reflash on the car.


So converting 1850 mbar to psi is like 28psi... really? wow...

dWiGhT

[dWiGhT]

Not 28psi

Check your calcs again Einstein. j/k

You do have a reflash on the car.

yeah... got that the car has a reflash...

so if you go here: http://www.sensorsone.co.uk/pressure-units-conversion.html

1850mbar = 28.28psi... its on the internet, it has to be true. ": /

so maybe it is 28psi - 14.7psi = 13.58psi... that would be more believable...

dWiGhT

[JRS-RS6]

yeah... got that the car has a reflash...

so if you go here: http://www.sensorsone.co.uk/pressure-units-conversion.html

1850mbar = 28.28psi... its on the internet, it has to be true. ": /

so maybe it is 28psi - 14.7psi = 13.58psi... that would be more believable...

dWiGhT

Thought sounds correct.


...You do have a reflash on the car.

How about block 002? What were the peak MAF readings added together?

[DHall1]

You may have one of the Vast tunes on the car. They had the check sum error as did Eurocharge before they fixed it.

Does the car go into limp mode when the CEL comes on? And how exactly do you clear the code? The car should stay in limp mode after a check sum error.

[V8weight]

You may have one of the Vast tunes on the car. They had the check sum error as did Eurocharge before they fixed it.

Does the car go into limp mode when the CEL comes on? And how exactly do you clear the code? The car should stay in limp mode after a check sum error.

If you either reset the ecu via disconnecting the battery, or clear the code with the vag-com, it goes back to normal. When I cleared the code with my generic OBD2-Can reader, it stayed in limp mode.

[dWiGhT]

How about block 002? What were the peak MAF readings added together?

didn't log 002... what info does that give me then?

Is there a list of the blocks and what they are? There doesn't seem to be a label file for VAGCOM for the RS6.

dWiGhT

[V8weight]

didn't log 002... what info does that give me then?

Is there a list of the blocks and what they are? There doesn't seem to be a label file for VAGCOM for the RS6.

dWiGhT
Block 002 displays your MAF g/s for banks 1 and 2. Add add the 2 values together and divide by .8 and you get an approximate hp number for any given rpm.

[ben916]

didn't log 002... what info does that give me then?

Is there a list of the blocks and what they are? There doesn't seem to be a label file for VAGCOM for the RS6.

dWiGhT

I know this information is on the forum and now that you brought it up, I or someone can search for it, but not tonight....

[V8weight]

http://www.ross-tech.com/vag-com/m_blocks/

[RS6Steve]

When doing these calcs work from the standard IAS 1013.25mb off your recorded boost, you must remember to remove atmospheric pressure.

So, 1850 - 1013.25 = 836.75 or 0.836 bar

Standard on these cars is 1.1bar, with your requested being 1950 and actual 1850 I'd suggest you have a boost leak? Plus you car is not mapped a mapped car would be call for around 2150mb and achieving it!

Now this is where you tell me the US have a completely different set up to the UK and I look stupid!

[RS6Steve]

You MAF values should be around 1.4 - 4.5 g/s at idle and up to about 225 g/s on full boost. they should be balanced within about 10% of each other, don't forget to select the turbo button on VAGCOM.

[dWiGhT]

When doing these calcs work from the standard IAS 1013.25mb off your recorded boost, you must remember to remove atmospheric pressure.

So, 1850 - 1013.25 = 836.75 or 0.836 bar

Standard on these cars is 1.1bar, with your requested being 1950 and actual 1850 I'd suggest you have a boost leak? Plus you car is not mapped a mapped car would be call for around 2150mb and achieving it!

Now this is where you tell me the US have a completely different set up to the UK and I look stupid!

so this is on California piss water... I mean, 91 oct fuel... does that effect the requested boost?

dWiGhT

[JRS-RS6]

didn't log 002... what info does that give me then?

Is there a list of the blocks and what they are? There doesn't seem to be a label file for VAGCOM for the RS6.

dWiGhT

PM me with your e-mail and I will send you the label file; however, it should be on your VCDS already. There is a list at their site and a link in the forum. I can send you a zip file of the pdfs I made from it too.

Block 002 has the Bank 1 and Bank 2 MAFs -- adding these gives the total math and a good rule of thumb (supposedly) as to take the two add them together and multiply by 1.25 to get an approximate peak HP rating.

[JRS-RS6]

When doing these calcs work from the standard IAS 1013.25mb off your recorded boost, you must remember to remove atmospheric pressure.

So, 1850 - 1013.25 = 836.75 or 0.836 bar

Standard on these cars is 1.1bar, with your requested being 1950 and actual 1850 I'd suggest you have a boost leak? Plus you car is not mapped a mapped car would be call for around 2150mb and achieving it!

Now this is where you tell me the US have a completely different set up to the UK and I look stupid!

It is also possible N75 is not working properly, the DVs are leaking internally, and it also depends on the engine RPM as at a certain point the exhaust pressure will blow off the waste gates because the stock springs are not strong enough. From the data I have seen to date it looks like these two variables account for power differences among stock and boosted cars the most. A single data point does not show us much. A graph of requested versus actual over RPM through the first three gears and also kicking down several times at highway speeds (60-80+) would be more telling than I asked for 1950 and I got 1830. When my car or anyone elses I have logged first asks for 1600+ we get 980 does that make them 600 mbar low or indicate a problem or does it show us the delay?

Log in Turbo mode, graph actual and requested versus RPM and than we can really see what is going on.

[RS6Steve]

Here are some of my logs for you to compare, my MAF numbers are now a lot better since I re seated them
RPM MAF1 MAF2 Boost Boost
(specified) (Actual)
4200 128.67 149.33 1650 1660
4360 138.28 155.92 1670 1700
4520 147.47 157.83 1690 1710
4680 154.39 161.14 1690 1690
4800 156.92 166.69 1710 1680
4960 160.94 174.89 1680 1680
5120 170.42 183.28 1650 1670
5280 174 188.03 1670 1680
5480 178.33 193.83 1690 1660
5680 181.17 202.56 1720 1660
5840 191.44 201.92 1700 1670
6040 201.03 207.47 1690 1700
6200 206.28 211.81 1690 1720
6360 201.5 208.42 1700 1730
6480 206.03 211.81 1710 1720
6560 203.64 215.22 1690 1740
6000 189.28 208.58 1700 1730
5240 163.72 186.11 1670 1690
4760 145.17 159.92 1660 1680
4800 146.44 160.19 1650 1650
4880 152.61 161.86 1640 1620
4960 158.83 169.25 1630 1640
5040 133.94 159.56 1570 1660
5080 103.56 119.89 1140 1460
5120 90.03 105.89 990 1280
4960 5.39 16.14 990 1360

I'm pretty sure I need new DV's as my boost does not drop off that fast

[JRS-RS6]

Here are some of my logs for you to compare, my MAF numbers are now a lot better since I re seated them
RPM MAF1 MAF2 Boost Boost
(specified) (Actual)
4200 128.67 149.33 1650 1660
4360 138.28 155.92 1670 1700
4520 147.47 157.83 1690 1710
4680 154.39 161.14 1690 1690
4800 156.92 166.69 1710 1680
4960 160.94 174.89 1680 1680
5120 170.42 183.28 1650 1670
5280 174 188.03 1670 1680
5480 178.33 193.83 1690 1660
5680 181.17 202.56 1720 1660
5840 191.44 201.92 1700 1670
6040 201.03 207.47 1690 1700
6200 206.28 211.81 1690 1720
6360 201.5 208.42 1700 1730
6480 206.03 211.81 1710 1720
6560 203.64 215.22 1690 1740
6000 189.28 208.58 1700 1730
5240 163.72 186.11 1670 1690
4760 145.17 159.92 1660 1680
4800 146.44 160.19 1650 1650
4880 152.61 161.86 1640 1620
4960 158.83 169.25 1630 1640
5040 133.94 159.56 1570 1660
5080 103.56 119.89 1140 1460
5120 90.03 105.89 990 1280
4960 5.39 16.14 990 1360

I'm pretty sure I need new DV's as my boost does not drop off that fast

A little better but it would be helpful to have time stamps too. From what you have above requested and actual are within +/- 30 mbar (<.5 PSI) most of the time. Now if your sampling every second you may need DVs but both being bad (notice the difference in MAFs on last data point). Seeing as the MAFs drop off as you drop RPM and there are only three requested points lower than actual before that if you are sampling Turbo mode than this would be response time -- would it not? If you are sampling every .1 sec what is the issue? I usually graph Requested and Actual Boost and RPM over time and scale the RPM to the right axis (4000 to 7000) and the Boost to the left (1000 to 2500). Run in Turbo mode this provides a sampling rate around once every .1 seconds. From the MAFs it looks like you peak around 520 HP