Cameron

Folks,

Here is a data logging run that I did this morning since completing a bit more finetuning on the fuel map using the SharkTuner. I did a 2nd gear rolling start with the WOT switch as the trigger for the data logger to start to capture data. I set it up for 30 samples per second. I wanted to start from about 2k rpm, but there was a car on my bumper so I couldn't slow down any more. I will post another when I have a chance to capture the transition from cruise to WOT. You will see that there is no tip-in lean condition whatsoever. Even in this one, you can see that as soon as the WOT switch is triggerred (that is the sample '0') the AFR goes down to the mid 12's in about 2 / 10 ths of a second an no leanness in between.

The average AFR across the sample set is 12.3. I was shooting for 12.2 and there was one shift in there so I am pretty happy.

For the math wizards, I went from 3276 rpms in 2nd to 6260 rpms in 3rd in 5.42 seconds according to the data.

Comments?



Time [s] RPM A/F ratio
0 3276 13.29
0.03 3285 13.07
0.07 3297 12.91
0.1 3311 12.7
0.13 3375 12.57
0.17 3430 12.66
0.2 3462 12.5
0.23 3506 12.65
0.27 3552 12.64
0.3 3608 12.46
0.33 3634 12.61
0.37 3683 12.61
0.4 3754 12.1
0.43 3800 12.42
0.47 3833 12.39
0.5 3861 12.65
0.53 3914 12.54
0.57 3955 12.53
0.6 4033 12.57
0.63 4057 12.28
0.67 4071 12.16
0.7 4134 12.36
0.73 4186 12.3
0.77 4209 12.27
0.8 4268 12.1
0.83 4289 12.08
0.87 4351 12.41
0.9 4406 12.67
0.93 4465 12.7
0.97 4478 11.75
1 4505 12.35
1.03 4539 12.62
1.07 4629 12.28
1.1 4659 12.09
1.13 4683 12.16
1.17 4725 12.26
1.2 4772 12.07
1.23 4844 12.31
1.27 4919 12.23
1.3 4965 12.1
1.33 4996 12.18
1.37 5035 12.24
1.4 5145 12.37
1.43 5128 11.57
1.47 5147 12.42
1.5 5237 12.73
1.53 5248 12.11
1.57 5326 11.98
1.6 5319 11.92
1.63 5422 11.93
1.67 5456 11.98
1.7 5470 12.2
1.73 5549 11.95
1.77 5584 11.73
1.8 5584 12.35
1.83 5645 12.74
1.87 5679 12.34
1.9 5771 11.95
1.93 5802 12.15
1.97 5854 12.45
2 5882 12.25
2.03 5928 12.48
2.07 5964 12.18
2.1 6026 12.23
2.13 5995 12.14
2.17 6004 12.38
2.2 6077 12.55
2.23 6170 12.31
2.27 6221 12.29
2.3 6198 12.25
2.33 6286 12.11
2.37 6339 12.29
2.4 6305 12.14
2.43 6412 12.13
2.47 6372 12.13
2.5 6535 12.14
2.78 5852 12.37
2.82 5537 13.74
2.85 5161 12.89
2.88 4881 12.72
2.92 4652 12.68
2.95 4602 12.81
2.98 4781 12.5
3.02 4860 12.29
3.05 4793 12.23
3.08 4810 12.35
3.12 4890 12.51
3.15 4879 12.12
3.18 4873 12.09
3.22 4892 11.78
3.25 4943 12.21
3.28 5001 12.28
3.32 4976 12.26
3.35 5003 11.85
3.38 5084 12.14
3.42 5042 12.32
3.45 5057 12.45
3.48 5122 12.14
3.52 5107 11.9
3.55 5131 12.2
3.58 5159 12.34
3.62 5170 12
3.65 5253 12.36
3.68 5239 12.18
3.72 5265 12.09
3.75 5230 12.03
3.78 5332 11.99
3.82 5326 12.01
3.85 5376 12.13
3.88 5362 12.42
3.92 5399 12.51
3.95 5442 12.09
3.98 5421 12.14
4.02 5488 12.39
4.05 5496 12.12
4.08 5474 12.17
4.12 5502 12.38
4.15 5557 11.95
4.18 5533 12.29
4.22 5574 12.27
4.25 5582 12.23
4.28 5641 12.4
4.32 5673 12.36
4.35 5647 12.41
4.38 5686 12.36
4.42 5686 12.45
4.45 5720 12.47
4.48 5775 12.24
4.52 5813 12.42
4.55 5818 12.26
4.58 5852 12.52
4.62 5850 12.31
4.65 5886 12.35
4.68 5896 12.38
4.72 5961 12.34
4.75 5935 12.31
4.78 5968 12.44
4.82 5966 12.25
4.85 5978 12.46
4.88 5961 12.42
4.92 6007 12.43
4.95 5997 12.55
4.98 6072 12.31
5.02 6137 12.4
5.05 6122 12.26
5.08 6092 12.13
5.12 6095 12.3
5.15 6172 12.1
5.18 6190 12.54
5.22 6155 12.25
5.25 6231 12.49
5.28 6273 12.47
5.32 6203 12.09
5.35 6247 12.21
5.38 6323 12.36
5.42 6260 12.36

sweanders

It looks very consistent. Where have you located the o2-sensor?

Cameron

O2 sensor in stock location.

sweanders

I have to say that I am very impressed compared to the A/F-logs on other 928 with stock chips and superchargers. The curves are usually from the mid 13's to low 10's IIRC.

Cameron

I did the 3rd gear tip in test at lunch. Data captured is 10 samples / second.

The fourth column is throttle position. You can see that the AFR is in the high 13's at light cruise in third gear. I started at about 2000 rpm. When I floor it, you can see the throttle position go from 2 to 3. 3 = WOT. Look at how the AFR jumps into the 11's by the next sample - within 1/10th of one second!

TIP IN IS GONE.

Also, the AFR stays in a pretty tight range across the RPM's when compared to before I did the SharkTuning.


Time [s] RPM A/F ratio Throttle pos (1=idle, 2=cruise, 3=WOT)
0 1861 13.87 2
0.1 1877 13.62 2
0.2 1881 13.57 2
0.3 1886 13.64 2
0.4 1889 13.72 2
0.5 1890 13.79 2
0.6 1896 13.84 2
0.7 1902 14.24 2
0.8 1916 13.77 2
0.9 1915 13.67 2
1 1927 13.73 2
1.1 1922 13.77 2
1.2 1932 13.58 2
1.3 1975 13.68 2
1.4 2046 11.19 3
1.5 2010 11.34 3
1.6 2098 12.18 3
1.7 2105 12.12 3
1.8 2180 12.87 3
1.9 2209 12.71 3
2 2258 13.24 3
2.1 2308 12.14 3
2.2 2350 12.35 3
2.3 2394 12.15 3
2.4 2433 12.14 3
2.5 2476 11.89 3
2.6 2518 11.9 3
2.7 2575 11.98 3
2.8 2620 12.01 3
2.9 2652 12.14 3
3 2713 11.9 3
3.1 2743 12 3
3.2 2801 12.15 3
3.3 2844 12.15 3
3.4 2878 12.07 3
3.5 2919 12.02 3
3.6 2974 12.04 3
3.7 3015 11.8 3
3.8 3058 12.11 3
3.9 3099 11.87 3
4 3143 12.56 3
4.1 3214 12.3 3
4.2 3232 12.17 3
4.3 3300 12.45 3
4.4 3321 12.48 3
4.5 3392 12.53 3
4.6 3409 12.25 3
4.7 3465 12.27 3
4.8 3527 13.27 3
4.9 3579 12.12 3
5 3615 12.39 3
5.1 3671 12.82 3
5.2 3694 13.3 3
5.3 3727 12.87 3
5.4 3812 12.85 3
5.5 3853 12.76 3
5.6 3881 12.53 3
5.7 3921 12.77 3
5.8 3933 12.34 3
5.9 4007 12.44 3
6 4057 12.78 3
6.1 4117 12.47 3
6.2 4150 12.68 3
6.3 4166 12.67 3
6.4 4219 12.48 3
6.5 4244 12.44 3
6.6 4317 12.36 3
6.7 4389 12.72 3
6.8 4382 12.9 3
6.9 4440 12.37 3
7 4503 12.51 3
7.1 4507 12.49 3
7.2 4588 12.18 3
7.3 4632 12.12 3
7.4 4655 12.12 3
7.5 4694 12.17 3
7.6 4774 11.95 3
7.7 4821 12.13 3
7.8 4829 12.25 3
7.9 4884 12.18 3
8 4918 12.04 3
8.1 4993 12.12 3
8.2 5033 12.19 3
8.3 5023 12.53 3
8.4 5131 12.12 3
8.5 5135 12.06 3
8.6 5186 12.32 3
8.7 5233 12.4 3
8.8 5257 11.36 3
8.9 5294 12.66 3
9 5382 12.01 3
9.1 5391 12.14 3
9.2 5468 12.62 3
9.3 5494 12.4 3
9.4 5496 12.06 3
9.5 5520 12.29 3
9.6 5605 12.21 3
9.7 5664 12.07 3
9.8 5660 12.46 3
9.9 5744 12.13 3
10 5729 12.05 3
10.1 5773 11.81 3
10.2 5852 11.96 3
10.3 5829 12.01 3
10.4 5877 12.04 2
10.5 5841 12.11 1
10.6 5549 12.1 1
10.7 5199 12.13 1
10.8 4985 12.14 1
10.9 4686 12.16 1
11 4366 12.13 1
11.1 4098 12.15 1
11.2 3834 12.15 2
11.3 3441 12.16 2
11.4 3086 12.18 2
11.5 3190 12.25 2
11.6 3212 12.25 2
11.7 3151 12.27 2
11.8 3153 12.24 2
11.9 3153 12.25 1

Tony

Nicely done! Very consistant.
Its good that your tuning on the road as i have found things are a little different than on the dyno.
Have you managed to drop your fuel pressures a bit now?

30# injectors?

One of these days i will get around to doing mine as well.
I need to get my spare MAF re done by MR Speake and gather all the chips and burner etc etc..whatever i need.

Cameron

Tony,

Thanks. I have not changed from the 'stock' Andy Keel setup with the 30# injectors and the 85/86 FPR. I removed the FP gauge that was on the front of the fuel rail after the install. I don't recall the idle fuel pressure, but I have it written down in notes somewhere. I am not planning on making any changes now, since my new chip will be optimized for my current setup.

AO

Here's a graphical representation of the 2nd run you posted (or were they the same run...? - anyway from the 2nd post). Very nice.

Tony

much easier to comprehend..thanks Andrew
How'd you get so smart

Cameron

Andrew,

Thanks for that!

The first run was different. It was a second gear rolling start continuing through 3rd gear. But the data logger was set to only trigger on a WOT throttle position (throttle position 3). Also, the first run logged 30 samples / second. The one you graphed logged 10 samples / second. If you could graph the first one, it will probably be a little more smooth for the higher sampling rate.

Larry928GTS

Does that log the fuel injector duty cycle as well? I remember there was some discussion a while back about whether there might be problems with the fuel injectors going to 100% duty cycle. Is this with one of the SuperMAFs that John has mentioned too?

AO

Ok Cam,
Here' the first Run. Note right hand scale (AFR) starts at 10, so you get close up detail.
...and Tony, I got so smart by growing up in Minnesota - you're only half as smart 'cause you only spend a few months a year there!

Cameron

Andrew,

Thanks again. Wow, that is a close up. First, I thought the AFR was really jumping around until I scaled it in my mind to the scale in the graphic.

Larry,

I do have the injector duty cycle information. When I have a moment, I will try to edit it in to the original post.

AO

Here is the graph with the same scale.

John Speake

Hello Larry,
Yes, the ST will log most paramters you need , including MAF volts and injector duty cycle. When running O2 closed loop at idle and cruise it will tell you how well the O2 loop is tracking the mixture.

Cameron has no problem with injector duty cycle as he is using 30# injectors with fairly stock fuel pressure.

He is using a standard MAF, and this is hitting its upper limit quite early on. so effectively he is mapping some of the WOT condition only based on rpm.

Using a SuperMAF would be essential if the power was any higher.

But the results he has achieved for mixture control and improved driving are excellent :-)