Dyno Results

[vaudiw]

I've just had my car dyno'd and got the attached result. It is running very lean and the mixture is all over the place. They wouldn't complete the dyno run due to the mixture.

Also the torque looks way too high.

The car has been chipped, but otherwise standard. The dyno guy pointed finger at the chip, but is there any other likely reason?

Interestingly an RS4 dyno'd just after me had the same problem with mixture and he is using the same chip company as me.

[dazzer]

What chip or remap is on the car?

Do you have VAG COM?

Running lean could be as a result of something other than the chip (MAF) but the company should have done a health check before mapping the car.

[vaudiw]

The remap is from http://www.ic-chiptuning.com/html/index.htm

I don't have VAG-Com but will be getting it scanned before I drive it again.

Unfortunately we don't have the likes of MRC down under so Health Checks are unheard of. It was scanned by when the map was done and no faults appeared. Also it had been serviced about a month prior by the main dealer.

It is peculiar that the AF line is so spikey, I would have thought it would be smooth even if it was lean.

It is really worrying that I could have done major engine damage with it running so lean. Since chipping I have done a track day, which in hindsight could have been fatal.

The car runs well, pulls strongly and feels more powerful since mapping. I would like to think it is something other than the map so any pointers would be appreciated.

[dazzer]

A failing MAF sensor will not show up on VAG COM. You need to run a real-time log to see how it's performing. Try unplugging the MAF if you can't do this and see if there is any difference in how it runs.

[Blue_Thunder]

Maybe you have a dodgy lambda sensor or MAF sending erratic signals to the ECU causing it to alter the fuelling?

[vaudiw]

Hi,

Logged a 3rd gear run today and got the following:

Engine speed Mass air flow Throttle angle Ign timing
TIME g/s 0-5deg=closed deg
Marker STAMP /min g/s % °BTDC
0.01 2960 68.33 21.6 19.5
1.28 3640 81.31 23.1 24
2.6 2400 61.17 31 23.3
4 2680 43.53 16.1 18
5.31 2760 22.61 9.8 34.5
6.61 2720 24.47 10.2 34.5
8.02 2760 22.47 9.8 36
56.7 1880 6.86 3.1 6.8
58 2760 20.81 9 36
59.21 2880 93.33 100 20.3
60.51 3440 190.33 100 8.3
61.82 4080 191.42 100 7.5
63.07 4640 204.42 100 11.3
64.4 5240 213.31 100 15.8
65.79 5720 220.36 100 15.8
67.25 6160 218.33 100 17.3
68.69 4840 14.67 6.7 18
70.03 2720 8.31 3.9 13.5
71.32 1160 6.56 2.7 3
72.64 800 4.58 1.6 3.8

What does it all mean?

Checked the FATS time and apparantly only putting out 247hp at the crank.

cheers,

[dazzer]

You haven't quite run it to redline but it looks like your MAF is goosed. Those sorts of readings are what I would expect for a standard car. A stage one remap should be 250+.

Change the MAF and run another log. Don't rag it until you have changed the MAF.

[vaudiw]

Thanks for the reply. I'll fit a new MAF as suggested.

Here's another log, which does go to Red line:

Group A: '003
Engine speed Mass air flow Throttle angle Ign timing
TIME g/s 0-5deg=closed deg
Marker STAMP /min g/s % °BTDC
0.01 2320 31.69 13.3 27
1.41 2440 20.06 8.6 33
2.72 2480 14.17 6.7 36.8
4.01 2680 89.94 100 20.3
5.33 3280 177.44 100 6.8
6.73 4000 184.75 100 6.8
8.09 4600 200.14 100 9.8
9.39 5120 206.31 100 13.5
10.78 5640 218.56 100 15
12.22 6080 218.64 100 20.3
13.71 6480 224.64 100 21
15.23 6800 227.61 100 19.5
16.73 5760 17.56 7.8 18
18.14 3440 12.06 5.5 13.5

Would the MAF be likely to cause such wild spikes on the A/F readings and cause lean mixture or is there something else I should be looking for?[/list]

[Blue_Thunder]

Would the MAF be likely to cause such wild spikes on the A/F readings and cause lean mixture or is there something else I should be looking for?

Yes it could because the ECU won't know how much air is being drawn in and therefore will not be putting the correct amount of fuel in.

[dazzer]

What Blue Thunder says. Your fuel is running way to lean and should be much richer WOT.

[KayGee]

The AFR isn't what I would call wild spikes, its the way it is graphed..... That is way to lean, fix that and I'm sure you wont see the "spikes".

[vaudiw]

I've ordered a MAF and pick it up today. Looking back at some old posts it looks like my MAF readings are not too bad. From what I've read 212 being about avg for a std car, and I'm showing up to 227.

Is there something else I should be checking? Should I replace the MAF anyway.. What other blocks should I log?

Here's some more from my last log - same MAF reading but with 2 more blocks. I was trying to capture the O2 sensor but don't know if I got it right Is this meaningful and do the numbers look OK?

Thanks for the comments so far..

[dazzer]

I've ordered a MAF and pick it up today. Looking back at some old posts it looks like my MAF readings are not too bad. From what I've read 212 being about avg for a std car, and I'm showing up to 227.

Is there something else I should be checking? Should I replace the MAF anyway.. What other blocks should I log?

Here's some more from my last log - same MAF reading but with 2 more blocks. I was trying to capture the O2 sensor but don't know if I got it right Is this meaningful and do the numbers look OK?

Thanks for the comments so far..

I would have expected to see the MAF higher for a stage 1 car. However it could just be the map. 227 equates to a theoretical HP of 283. When I was at stage 1 my MAF readings were 260-264 which is up around 320-330 HP. Mine had a Milltek cat back perhaps offering a little gain. IIRC my peak boost was slightly more than you are running. I dont know what the two ends of the voltage signal from the O2 sensor are (someone may know) but if they were knackered I would have expected VAG COM to show up a DTC (anyone!!). Aside from that at WOT the O2 sensor is ignored as the ECU is operating in Open loop mode and would be enriching the mixture. Thing is it doesn't appear that you have any DTC triggered by excessive EGTs either caused by running lean.

Maybe it's the remap or the RR!! Perhaps you need some MRC goodness.

[vaudiw]

Thing is it doesn't appear that you have any DTC triggered by excessive EGTs either caused by running lean.

Sorry, but what does this mean?

I would love some "MRC Goodness" but I don't think they make house calls to this end of the world

Cheers.

[dazzer]

Thing is it doesn't appear that you have any DTC triggered by excessive EGTs either caused by running lean.

Sorry, but what does this mean?

I would love some "MRC Goodness" but I don't think they make house calls to this end of the world

Cheers.

I am just saying that VAG COM has not shown any high EGTs. High EGTs would normally be exhibited when running lean. So despite the apparent leaness recorded on your RR graph maybe you aren't running lean. The AFRs are lean on the graph for a car at WOT which leads me to think that there maybe something wrong with the RR graph. What ECU do you have in your car - can you log the EGTs? If you want to log AFRs then try and find someone who can fit some wideband sensors and has the kit (such as an LM1) to log the results.

Your MAF may be OK and that's the power you are getting out of your car period. If you want MRC magic they can provide a generic chip/map I am sure. I am pretty sure someone has installed some MRC magic in your neck of the woods by post!