I promise to post the solution

[RS6-4dr911]

Yes, this is much improved (about 1/2 sec to 60 and noticeably improved top end performance) after the IC replacement. The Apikols are only slightly smaller than the Wagners and most of those user have reported no increase in lag, which stands to reason given the volume of the entire pressurized system vs. the minor increase in the IC volume.

You asked for 0-60 times, posted below for comparison:

Sunday,24,January,2010,14:36:20:28960
Control Module Part Number: 4D1 907 558 D Component and/or Version: 4.2l V8/5VT G 0003

Metric units
0 to 100 km/h: 5.7 +- 1.03s
400m: 19.8 +- 0.99s, @55 km/h
90-120 km/h:
200 meters: 9.4 +- 1.01s, @98 km/h

US Units
0 to 60 mph: 5.4 +- 1.03s
1/4 mile: 20.0 +- 0.99s, @34 mph
60-90 mph:
660 feet: 9.4 +- 1.01s, @61 mph

Time(s) km/h m
0.00 0.0 0.0
0.50 1.0 0.1
1.00 12.0 1.8
1.52 23.0 5.1
2.04 35.0 10.2
2.55 47.0 16.9
3.07 57.0 25.0
3.58 66.0 34.5
4.10 75.0 45.3
4.61 82.0 56.8
5.12 89.0 69.5
5.63 96.0 83.0
6.15 103.0 98.0
6.66 109.0 113.4
7.17 112.0 129.3
7.69 111.0 145.3
8.20 109.0 160.8
8.71 105.0 175.7
9.22 100.0 189.8


Sunday,24,January,2010,14:39:43:28960
Control Module Part Number: 4D1 907 558 D Component and/or Version: 4.2l V8/5VT G 0003

Metric units
0 to 100 km/h: 6.0 +- 1.04s
400m:
90-120 km/h:
200 meters: 9.7 +- 1.03s, @92 km/h

US Units
0 to 60 mph: 5.7 +- 1.03s
1/4 mile:
60-90 mph:
660 feet: 9.7 +- 1.03s, @57 mph

Time(s) km/h m
0.00 0.0 0.0
0.52 1.0 0.1
1.04 9.0 1.4
1.55 20.0 4.3
2.07 30.0 8.6
2.58 42.0 14.5
3.08 52.0 21.8
3.61 62.0 30.9
4.12 70.0 40.8
4.64 78.0 52.1
5.15 85.0 64.2
5.65 92.0 77.0
6.16 99.0 90.9
6.68 106.0 106.3


Sunday,24,January,2010,14:41:28:28960
Control Module Part Number: 4D1 907 558 D Component and/or Version: 4.2l V8/5VT G 0003

Metric units
0 to 100 km/h: 5.9 +- 1.01s
400m: 23.3 +- 1.02s, @29 km/h
90-120 km/h:
200 meters: 9.4 +- 1.01s, @103 km/h

US Units
0 to 60 mph: 5.6 +- 1.01s
1/4 mile: 23.7 +- 1.01s, @17 mph
60-90 mph:
660 feet: 9.4 +- 1.01s, @64 mph

Time(s) km/h m
0.00 0.0 0.0
0.50 1.0 0.1
1.02 12.0 1.9
1.54 22.0 5.1
2.05 33.0 9.7
2.57 44.0 16.0
3.08 54.0 23.8
3.58 63.0 32.5
4.08 72.0 42.6
4.59 79.0 53.8
5.11 86.0 66.1
5.64 93.0 79.7
6.14 100.0 93.8


Sunday,24,January,2010,14:47:10:28960
Control Module Part Number: 4D1 907 558 D Component and/or Version: 4.2l V8/5VT G 0003

Metric units
0 to 100 km/h: 6.2 +- 1.04s
400m: 26.8 +- 1.04s, @24 km/h
90-120 km/h:
200 meters: 9.5 +- 1.04s, @103 km/h

US Units
0 to 60 mph: 5.9 +- 1.04s
1/4 mile: 27.3 +- 1.04s, @15 mph
60-90 mph:
660 feet: 9.5 +- 1.04s, @64 mph

Time(s) km/h m
0.00 0.0 0.0
0.52 1.0 0.1
1.01 11.0 1.6
1.51 20.0 4.4
2.01 30.0 8.6
2.52 40.0 14.3
3.03 51.0 21.4
3.55 60.0 30.2
4.08 69.0 40.2
4.59 76.0 51.1
5.11 83.0 63.0
5.61 89.0 75.4
6.12 96.0 89.0
6.64 102.0 103.8



Sunday,24,January,2010,14:48:15:28960
Control Module Part Number: 4D1 907 558 D Component and/or Version: 4.2l V8/5VT G 0003

Metric units
0 to 100 km/h: 6.0 +- 1.02s
400m:
90-120 km/h:
200 meters: 9.7 +- 1.03s, @83 km/h

US Units
0 to 60 mph: 5.7 +- 1.04s
1/4 mile:
60-90 mph:
660 feet: 9.7 +- 1.03s, @52 mph

Time(s) km/h m
0.00 0.0 0.0
0.52 4.0 0.6
1.03 15.0 2.7
1.54 25.0 6.2
2.04 35.0 11.1
2.54 45.0 17.4
3.06 55.0 25.3
3.58 64.0 34.5
4.10 73.0 45.0
4.61 80.0 56.4
5.12 86.0 68.6
5.63 93.0 81.7
6.14 99.0 95.8
6.64 105.0 110.4



Sunday,24,January,2010,14:50:27:28960
Control Module Part Number: 4D1 907 558 D Component and/or Version: 4.2l V8/5VT G 0003

Metric units
0 to 100 km/h: 5.8 +- 1.06s
400m: 16.5 +- 1.03s, @65 km/h
90-120 km/h: 2.7 +- 1.01s
200 meters: 8.9 +- 1.03s, @128 km/h

US Units
0 to 60 mph: 5.5 +- 1.06s
1/4 mile: 16.6 +- 1.03s, @40 mph
60-90 mph:
660 feet: 8.9 +- 1.03s, @80 mph

Time(s) km/h m
0.00 0.0 0.0
0.51 7.0 1.0
1.00 17.0 3.3
1.51 27.0 7.1
2.00 37.0 12.2
2.54 49.0 19.5
3.06 58.0 27.8
3.56 67.0 37.3
4.08 74.0 48.0
4.58 81.0 59.0
5.10 88.0 71.8
5.59 94.0 84.7
6.14 101.0 100.0



Sunday,24,January,2010,15:00:25:28960
Control Module Part Number: 4D1 907 558 D Component and/or Version: 4.2l V8/5VT G04 0003

Metric units
0 to 100 km/h: 6.1 +- 1.01s
400m: 23.5 +- 1.02s, @30 km/h
90-120 km/h: 2.9 +- 1.01s
200 meters: 9.2 +- 1.01s, @119 km/h

US Units
0 to 60 mph: 5.8 +- 1.03s
1/4 mile: 23.8 +- 1.02s, @19 mph
60-90 mph:
660 feet: 9.2 +- 1.01s, @74 mph

Time(s) km/h m
0.00 0.0 0.0
0.50 5.0 0.7
1.00 15.0 2.8
1.52 25.0 6.4
2.04 35.0 11.5
2.55 45.0 17.9
3.07 55.0 25.7
3.58 63.0 34.6
4.08 71.0 44.5
4.61 78.0 55.9
5.12 85.0 68.0
5.63 91.0 80.9
6.15 98.0 95.2
6.66 104.0 110.0



Sunday,24,January,2010,15:03:11:28960
Control Module Part Number: 4D1 907 558 D Component and/or Version: 4.2l V8/5VT G04 0003

Metric units
0 to 100 km/h: 6.1 +- 1.02s
400m: 24.4 +- 1.01s, @45 km/h
90-120 km/h:
200 meters: 10.1 +- 1.02s, @76 km/h

US Units
0 to 60 mph: 5.8 +- 1.02s
1/4 mile: 24.5 +- 1.01s, @28 mph
60-90 mph:
660 feet: 10.1 +- 1.02s, @47 mph

Time(s) km/h m
0.00 0.0 0.0
0.51 3.0 0.4
1.03 14.0 2.4
1.55 24.0 5.9
2.06 34.0 10.7
2.58 45.0 17.2
3.07 54.0 24.6
3.59 63.0 33.7
4.10 71.0 43.8
4.63 78.0 55.2
5.15 85.0 67.5
5.66 91.0 80.5
6.17 98.0 94.3
6.68 104.0 109.1


Sunday,24,January,2010,15:07:14:28960
Control Module Part Number: 4D1 907 558 D Component and/or Version: 4.2l V8/5VT G04 0003

Metric units
0 to 100 km/h: 6.1 +- 0.67s
400m: 22.7 +- 0.67s, @41 km/h
90-120 km/h:
200 meters: 9.4 +- 0.66s, @109 km/h

US Units
0 to 60 mph: 5.8 +- 0.66s
1/4 mile: 22.9 +- 0.68s, @26 mph
60-90 mph:
660 feet: 9.4 +- 0.66s, @65 mph

Time(s) km/h m
0.00 0.0 0.0
0.33 5.0 0.5
0.68 12.0 1.6
1.02 18.0 3.3
1.37 24.0 5.7
1.71 31.0 8.6
2.06 38.0 12.2
2.40 45.0 16.5
2.74 51.0 21.4
3.08 57.0 26.8
3.43 62.0 32.8
3.77 68.0 39.1
4.12 73.0 46.3
4.46 77.0 53.6
4.81 82.0 61.5
5.16 86.0 69.8
5.49 90.0 78.1
5.84 94.0 87.2
6.17 99.0 96.4
6.51 103.0 106.0



Sunday,24,January,2010,15:08:32:28960
Control Module Part Number: 4D1 907 558 D Component and/or Version: 4.2l V8/5VT G04 0003

Metric units
0 to 100 km/h: 6.2 +- 0.69s
400m: 25.3 +- 0.69s, @31 km/h
90-120 km/h:
200 meters: 9.8 +- 0.69s, @87 km/h

US Units
0 to 60 mph: 5.9 +- 0.68s
1/4 mile: 25.5 +- 0.66s, @20 mph
60-90 mph:
660 feet: 9.8 +- 0.69s, @54 mph

Time(s) km/h m
0.00 0.0 0.0
0.34 1.0 0.1
0.67 8.0 0.8
1.01 15.0 2.2
1.34 21.0 4.2
1.67 28.0 6.7
2.02 35.0 10.1
2.37 42.0 14.2
2.71 48.0 18.8
3.05 55.0 23.9
3.39 61.0 29.8
3.74 66.0 36.1
4.08 71.0 42.8
4.42 76.0 50.0
4.76 80.0 57.7
5.11 85.0 65.8
5.45 89.0 74.2
5.78 93.0 82.9
6.13 97.0 92.1
6.48 101.0 101.9

[dmross]

The time difference to pressurize the OEM vs. aftermarket intercoolers is not a factor, because it is in the realm of microseconds.

A leak in the intercooler is a different story, because you are leaking metered air which would result in the car running rich, potentially robbing you of power.

[Shoppinit]

I thought the air was metered after the turbos / IC ?

EDIT: Sorry, I'm talking rubbish. You're quite right.

[Shoppinit]

This is actually quite a complex problem because even if you are making full power, it doesn't mean that your performance is there. It's when you make full power and what happens up the rpm curve that is important.

This is my thinking, and if I'm wrong then please let me know:

1. You control the amount of power request via the accelerator pedal
2. The car opens the throttle to achieve requested power
3. The MAF measures the amount of air being sucked / blown into the engine
4. The ECU uses the MAF value to fuel the engine. It corrects natural variation in MAFs with the O2 sensor information and adjusts the fueling.
5. Ignition is advanced / retarded to get max efficiency without pinking / knocking

Does this sound right?

[RS6-4dr911]

This is actually quite a complex problem because even if you are making full power, it doesn't mean that your performance is there. It's when you make full power and what happens up the rpm curve that is important.

This is my thinking, and if I'm wrong then please let me know:

1. You control the amount of power request via the accelerator pedal
2. The car opens the throttle to achieve requested power
3. The MAF measures the amount of air being sucked / blown into the engine
4. The ECU uses the MAF value to fuel the engine. It corrects natural variation in MAFs with the O2 sensor information and adjusts the fueling.
5. Ignition is advanced / retarded to get max efficiency without pinking / knocking

Does this sound right?

1. Correct.
2. Correct.
3. sucked, MAF's are upstream of turbos
4. Correct.
5. Correct.

[Shoppinit]

Thanks. So would a dodgy MAF would cause the O2 correction to go out of bounds and throw a DTC, right? So if lambda values are sensible, then the MAF must be OK?

[dmross]

Thanks. So would a dodgy MAF would cause the O2 correction to go out of bounds and throw a DTC, right? So if lambda values are sensible, then the MAF must be OK?

A MAF that isn't reading accurately is one of many things that could cause this. The O2 sensor itself could be failing, or as you could have a hotside leak somewhere (intercooler, piping, intake manifold), etc.

An easy way to determine if the MAF is ok is to check that both are reading in a similar range. Although it's not a perfect test, chances are they aren't both bad, so if one is off significantly, it might indicate a problem with the MAF or the intake plumbing on that side.

You bring up an interesting point regarding "sensible" lambda values. The correction can actually vary quite a bit depending on the type of fuel used. Additionally, a relatively new problem that is often overlooked is the increased used of ethanol in pump fuel. This is especially noticeable on a finely tuned car. It can throw target AFRs off significantly. ECUs that learn long term fuel trims can get confused as well, especially if you fill up at different gas stations with varying ethanol content. I always try to stick with the same gas station if possible when troubleshooting, it's just one more variable that can throw off testing.

[RS6-4dr911]

An easy way to determine if the MAF is ok is to check that both are reading in a similar range. Although it's not a perfect test, chances are they aren't both bad, so if one is off significantly, it might indicate a problem with the MAF or the intake plumbing on that side.

And that's the $64 question - what is a "similar range"? 5%? 10%? 20% As an average throughout the rpm range? At any point?

My variation is quite large (as much as 25%) at low RPM's but narrows to 10% +/-2% at WOT and 3500rpm and up. So what say you to that?

[Shoppinit]

Mine too. But I think that both would degrade at the same rate. The MAF is a hot wire and any contaminents will burn onto it, reducing their effeciency, theoretically at the same rate. (this is why oiled air filters are a big no-no).

The BMW fraternity seem to like cleaning theirs. Interesting thread I came across:

http://forum.e46fanatics.com/showthread.php?t=335561

[p3u]

Mine too. But I think that both would degrade at the same rate. The MAF is a hot wire and any contaminents will burn onto it, reducing their effeciency, theoretically at the same rate. (this is why oiled air filters are a big no-no).

The BMW fraternity seem to like cleaning theirs. Interesting thread I came across:

http://forum.e46fanatics.com/showthread.php?t=335561

agree with them 100% i even use crc cleaner on the mafs, works like a charm.

[Shoppinit]

Can't get the CRC MAF cleaner where I live. I also kinda agree with the 3rd post on this thread:

http://tinyurl.com/ygm3vdb

[batty]

vagcom has quite a slow sampling rate.
do the MAF readings show a different time stamp, hence showing a different MAF reading from side-to-side, as vagcom records different poits on the airflow vs time curve ??

[RS6-4dr911]

vagcom has quite a slow sampling rate.
do the MAF readings show a different time stamp, hence showing a different MAF reading from side-to-side, as vagcom records different poits on the airflow vs time curve ??

Are you Paul_23 on RS246? same question raised there. If not:

Correct it does not log all data at the exact same time, but if you look at the raw data, reading across the columns, each you time you hit a "Time Stamp" column, everything to the right of that was taken at the same time until you hit another "Time Stamp" column. To my knowledge, all left/right bank data (MAF, Lambda, others) is logged at the same time, so for the variation between MAF's this is not a concern. Even if there are data that are logged at different stamps, the intervals are the same and it is pretty accurate to interpolate linearly between the readings and graph data with adjusted values to eliminate this problem. I've done it with transmission data trying to determine slippage where, IIRC, shaft RPM's and engine RPM's and Vehicle speed were logged at different times. Interpolation made for a much closer correlation between the data, showing that the box was sound.

[Shoppinit]

There's a turbo button so that samples are taken every 0.1 secs. I always try to log in turbo mode if I can.

[RS6-4dr911]

Maybe I'm missing another file. Mine's always grayed out and says something like "will not work with this interface", which is a USB cable that they recommend for that year of car.

[Shoppinit]

if you look at the raw data, reading across the columns, each you time you hit a "Time Stamp" column, everything to the right of that was taken at the same time until you hit another "Time Stamp" column.

This is my understanding also. All the data in one measuring block can be assumed to be simultaneously measured. The same is not true from one measuring block to another, as is shown by the different time stamp.

[RS6-4dr911]

Replaced MAF's, top seals and N75 today. Variance between the two banks narrowed by roughly 40%, average flow reading increased by almost 7%.

Butt dyno says snappier off the line, waiting for dry weather to clock 0-60 to verify.

[DHall1]

Big change.

Looking better

Replaced MAF's, top seals and N75 today. Variance between the two banks narrowed by roughly 40%, average flow reading increased by almost 7%.

Butt dyno says snappier off the line, waiting for dry weather to clock 0-60 to verify.