Logged a Couple runs have a couple questions

[SteveR6]

Ok, so I went out and played around with the SAFC for like the second time today. I reread the tech article and I have a few questions. I'm unfortunately running the stock 450 cc injectors so in theory would my car be faster with less boost because I could keep the correction values down and get more timing or would my car be faster running more boost and compensating with positive correction values on the SAFC. I know that + values will tell the ECU to keep the timing down for safety reasons and advance = power but so does boost. I'm runing right around 17psi on a 14B with the stock intercooler and Sunoco 94 octane. My first run I set the correction values at -2 up to 5K then 0d through the rest of the RPMs, with this I pulled timing at 6421 from 20 to 18 then gradually progressed back to 21 at 6898rpms, my airflow also dipped .12 from 5500 to 5600. I then changed the SAFC to -2 up to 5K, +5 at 5.6K, +5 at 6K, +10 at 6.6K, and +10 at 7.2K. This time I pulled one degree of timing between 4886 and 5175 (12,11,13). The airflow dip now was a steady 26.21 between those two rpms and I got no upper rpm pulled timing however I only got 19 degrees of timing at 6917rpm. What do you think? I guess I'll post both the logs even though it takes forever, stay tuned, and thanks in advance.

 

[SteveR6]

My points are set at 2, 2.6, 3, 3.6, 4, 4.6, 5, 5.6, 6, 6.6, and 7.2. This log is -2 correction up to 5K, then I set it to zero for the rest of the rpms.
rpm timing airflow
3964 7 18.25
4105 8 18.96
4226 8 19.62
4359 8 20.40
4464 8 20.80
4597 10 21.41
4714 10 21.62
4832 11 22.31
4949 12 22.93
5062 12 23.06
5199 12 23.54
5285 13 24.03
5394 14 24.05
5500 14 24.36
5597 16 24.24
5710 16 24.63
5796 17 25.00
5894 18 25.09
5980 18 25.13
6062 18 25.25
6132 18 25.43
6207 18 25.60
6308 20 25.81
6367 20 25.78
6421 18 25.80
6492 18 25.87
6550 18 26.05
6609 18 26.13
6667 19 26.22
6726 19 26.34
6773 20 26.35
6800 21 26.35
6843 21 26.21
6898 38 7.37

 

[SteveR6]

And the second, -2 correction up to 5K, +5 at 5.6 and 6K, +10 at 6.6 and 7.2
4007 8 18.97
4171 8 19.71
4335 9 20.19
4484 9 20.89
4625 10 21.50
4753 11 22.34
4886 12 22.88
5027 11 23.54
5175 13 24.23
5320 13 25.16
5433 13 25.79
5554 14 26.21
5656 15 26.21
5781 15 26.65
5902 17 26.97
5992 17 27.05
6121 17 27.57
6187 18 27.80
6285 18 27.95
6371 18 28.33
6464 18 28.53
6531 18 28.69
6609 18 28.80
6679 19 29.06
6746 19 29.13
6812 19 28.90
6867 19 29.16
6917 19 29.11
6984 38 6.26

 

[SteveR6]

I find it hard to believe noone has an opinion on these logs . I made some adjustments of my own I'm going to go make a run and I'll post the new log.

 

[JayRolla]

The first log looks better. At about 6400rpm it looks like you get some knock and the timing pulls. I would add a little bit of fuel above this and see if it helps the knock. The second log looks real bad, you get knock real early. I would go back the the first settings and work off those. Im a nuub with tuning also but I do know you want your tiiming curve to be smooth. No dips at all, if there is this indicates knock.

 

[CanadianTSi]

Seeing as your one the stock Injectors just leave it at 0.

 

[JayRolla]

He cant add a little fuel with stock injectors, I thought you could get a little more out of them.

 

[SteveR6]

I would think you can add a little on the stock injectors, but then it's going to keep the tmiing down. I'll put it back to the first log settings plus a little fuel on top and see what that nets.

 

[SteveR6]

Ok, new log
4535 9 22.96
4703 9 23.88
4882 10 24.73
5085 12 26.04
5277 12 26.88
5445 13 27.40
5593 14 27.83
5750 14 28.11
5914 15 28.55
6023 15 28.99
6152 15 28.97
6277 17 29.14
6378 18 29.24
6492 18 29.32
6550 18 29.15
6589 18 29.25
6625 18 29.40
6671 18 29.53
6718 18 29.80
6812 18 13.60
6632 38 3.8

 

[Rice Over Wheat]

I'm wondering why you corrected so much on the 2nd log. For every 1 point of timing I lose, I generally +/- 1% of correction and try another pull. If that's not enough I adjust another 1%.

When I had 450s and stock smic on my T28 @ 15 psi, I had my SAFC settings at -5% tops for HI. That's what net me my best dyno numbers. Pushing the boost to 18 psi and resetting to 0 or positive correction made me lose power. The 450s didn't have much left in them beyond 15 psi, but the biggest bottleneck was the stock smic that couldn't keep the intake temps down at higher psi (not to mention at 15 psi).

You're going to have a tough time squeezing any more power out without better intercooling and fuel delivery. Maybe water/meth injection, but I'd lose the smic first and you still need more fuel.

 

[SteveR6]

Because I'm an idiot and was basically just experimenting. I'm going to go down in a minute and reset it to -1 across the board and see what happens. I figure that will be a good base to work from. Unfortunately it's dark now and my "test area" may have cops lurking in the shadows

 

[Rice Over Wheat]

Nah, it takes time and experimentation to get the tuning thing down. I'm learning myself and pretty much everyone is at some level because it only gets more advanced (more variables to consider) as you make more and more power.

The stock smic gets heatsoaked very easily, so make sure you give plenty of time to cool between pulls. Even on the dyno we had to give 10 minutes to cool with a big ass fan blowing right into it. Yet it always made my subsequent runs lose power. I was so glad to be rid of that thing.

You should consider an SS Autochrome fmic off ebay and install it yourself. It'll only run you $300 after it's all done and you'll have a much better time tuning. After that, all you need is a 190 lph fuel pump and 550 injectors and you'll be good to go.

 

[SteveR6]

Ok, got another log, this one is much better I think, only pulled timing once at 7K
4527 8 22.47
4667 9 22.70
4824 10 23.85
4941 11 24.27
5062 11 24.57
5144 11 24.92
5226 11 25.08
53.16 12 25.31
5410 13 25.82
5562 14 25.93
5722 15 26.24
5851 16 26.44
5980 17 26.83
6109 17 27.05
6234 19 27.24
6351 19 27.38
6472 19 27.52
6566 19 27.46
6660 19 27.77
6738 20 27.60
6804 20 27.53
6863 20 27.39
6925 21 27.17
6957 20 27.26
7003 38 6.92

 

[Rice Over Wheat]

That looks good! Just add 1% at 7000 and try another run. If it stays smooth all the way through, you can try adding a bit more boost and tuning again. However, if you only get less timing then your injectors are probably maxed because you're only getting more airflow. Also, on that smic you'll hit a point where more boost doesn't get you any more performance because it can't cool the hotter air. And it won't be long beyond 16psi.

What psi was that log at?

 

[SteveR6]

17 psi on a 14B

 

[CanadianTSi]

That Log is perfect, don't touch a Thing.

If your seriously going to worry about losing 1 degree of (already high) timing at 7000 rpms then your going to go crazy trying to tune later on.

 

[andymoraitis]

I respectfully disagree. One degree of timing pull is 10 counts of knock on a 2G. I'd add fuel back in at 7000 or shift before then. If you're on stock cams, there's no point in going above 6700-6800 anyway since the cams won't support more airflow at higher RPM.

 

[CanadianTSi]

I respectfully disagree. One degree of timing pull is 10 counts of knock on a 2G.

Not necessarily Andy, could have been High Coolant temp or High Intake Temp.

 

[SteveR6]

Ahhhhh...perhaps that's why my airflow numbers are goofy in the upper rpms.

 

[SteveR6]

Airtemp was 62 at the start and 57 at 6800-7003 RPMs

 

[Rice Over Wheat]

That's why I suggested just adding the 1% near 7000 and trying another pull. When you can compare the different runs you'll have a frame of reference to decide whether you should keep it the same or not. You can always put it back to where it was in the run that was almost perfect.

Multiple runs under similar conditions is the only way to get results near a mean average. If you just use that one run for reference, any outlying variable could have given you those results.

That's what I do anyway before pushing the envelope further and further.

 

[SteveR6]

Exactly, it's all about correlation I learned some stuff in all those science classes in college It's hard to just go out and log runs though considering I'm topping out well into the 100s on the highway and I'm not really in the mood to get more tickets.

 

[Rice Over Wheat]

Long highway on-ramps at about 3am is usually a good bet. Cops typically aren't trapping people accelerating onto the highway entry lane. It's a pain though. I prefer a dyno but until $ grows on trees...