Help diagnosing log

[crashed97tsi]

Hey guys,

I just got done making a run trying to tune my car. The run was made on a AGP t28 with a warlboro 190lph and stock injectors. Settings on the SAFC was +1% low across the board, -3% high across the board. TH points set at 30% and 80%.

I would like to hear what others think I should do because I am still very new to this. If I understand it correctly, I want a timing curve that keeps advancing. There are a couple places where My timing retards, at 4480 and 6388. I should add fuel at the 4000 and 6000 rpm increment, right?

Other than those two points, does the rest of the log look ok?

One last question, do you need to set the lo fuel trims at all with stock injectors? My fuel trim maps seem to be fine without any adjustment, it just has to correct bigger numbers whenever I play with it.



RPM TPS TIMING O2
3624 97% 10 .92v
3832 97% 10 .92v
4036 97% 11 .94v
4260 97% 12 .94v
4480 97% 11 .94v
4688 97% 11 .94v
4920 97% 11 .94v
5144 97% 11 .94v
5360 97% 11 .94v
5556 97% 13 .94v
5772 97% 14 .94v
6008 97% 14 .94v
6172 97% 17 .94v
6388 97% 15 .92v
6552 97% 15 .94v
6712 97% 16 .94v
6868 97% 16 .94v
7032 97% 16 .94v
7164 97% 17 .92v
6064 0% 35 .48v

thanks for the help

 

[Zerocygnal]

Good timing to aim for at WOT is 21BTDC, wether it climbs or not is going to depend on your knock.

Unrelated but try readjusting your throttle cable. TPS should be at 99% or 100% at WOT. Get every little bit you can right?

My suggestion would be to tune for .92v minimum. ( I think this was the recommended value for a 2G.)

By the timing numbers you've put up, it looks like you're getting just enough knock to pull a degree or two of timing and keep it from climbing. What are your EGT's if any?

 

[crashed97tsi]

At WOT their at 1500, maybe 1550. At cruising their at 1400 for some reason. I've also heard that .92 is the number to shoot for but that it;s different on every car. I'm guessing I have knock because my timing gets pulled a little. So I guess .94 is my car's magic number then?

thanks for the help

 

[DCJ98GST]

What boost psi?
What octane gas?

 

[candela]

What boost psi?

Yes I agree you need to tell more than this and also update your profile so we can help. If you are on 93 ocatane and you have a reiwred 190lph you shoudl first try and start for a little bit leaner line across. I also like to set my throttle points a bit different as well. The only time Im really at like less than 30% is when Im cruising in 4th or 5th and I want to increase speed a little bit. When your in those gears there is a much higher load on the motor and boost will usually come up. I had mine set at I think 20% for low and 85% for high, which worked for me great! your EGT's look aight, but you should have much more timing throughout the entire range. What boost are you running? What octane?

 

[Zerocygnal]

From the evidence listed so far you have knock. Timing is in fact being lost.
Candela..you don't think the EGT's seem a little hot for cruise? Just curious, thought typical was about 1100 or so cruising.

We definately need to know what psi and octane you are using. You may be running a bit to much boost if your knocking like that. 1550 (IMO) is pushing the envelope it has to be knocking. But Candela's the one running 12's so I'd probably take his word for it.

Got Fuel Trims?

 

[crashed97tsi]

Ok, sorry for the lack of info.

the runs are all made on 14 psi, 93 octane gas. I have a rewired 190lph, stock injectors. My egt's have always been high since I installed it on the car, but they were usually at 1300 before.

My low fuel trims are weird, I try to set them but whatever setting I choose seems to just make the ecu have to adjust more. For example, I was getting readings that it needed more fuel in the low setting. So i added fuel +2%. 15 minutes later I started it up again to check and it wanted less fuel, so I leaned it out -1%. Then the ecu started correcting into the positive. I don't know if this is making any sense but it seems that 0% is where the low wants to be set.

thanks for the help guys.

 

[crashed97tsi]

Ok, here's what I'm talking about with my fuel trims. I don't know if this will help at all, but I'll post it anyway.


STFT LTFT RPM TPS
0% 4% 3072 14%
0% 5% 3044 14%
0% 4% 3048 14%
-1% 4% 3044 15%
-1% 4% 3040 15%
0% 4% 3028 17%
0% 4% 3040 18%
-3% 4% 3040 18%
0% 4% 3044 18%
-1% 4% 3044 14%
0% 4% 3036 0%
-5% 0% 2976 0%
3% 0% 2988 14%
0% 4% 2956 15%
-1% 4% 2964 15%
-2% 4% 2968 16%
-1% 4% 2976 16%
0% 4% 2980 16%
0% 4% 2980 17%
-1% 4% 2992 18%
-2% 4% 3008 19%
-2% 4% 3016 19%
-3% 4% 3032 20%
-3% 4% 3040 20%
-3% 4% 3064 20%
-2% 4% 3088 19%
0% 4% 3096 18%
0% 4% 3116 18%
-1% 4% 3132 17%
0% 4% 3140 17%

That was some of my drive home. I logged the trims as I was going. I set them by using kpt's guide. The settings were +3% across. does this look ok?

Once again, thanks for the help guys.

 

[Blk_99gst]

Hmm, Your fuel trims are opposite of what they should be and what I expected them to be. First off, when tuning low safc settings, you look at both short term and long term fuel trims, but what really matters is long term fuel trims (short term changes so much, but long term ones show how things are in, well the long run!)

So what your long term fuel trims are saying in the log below, is that the ecu is having to add 4% (+4%) more fuel for it to obtain what it thinks is an ideal condiction. Normally to correct something like this, you would change the low-safc settings to add 4% more fuel (i.e. if your settings ar +3%, then changing them to +7% is adding more fuel).

Now what totally doesn't make since to me is that you have the stock injectors and if you had the low settings set to zero on the safc, then it would act like the safc wasn't even in the system (normally stock car). I would think by you having a +3% safc settings, that the ecu would have long term fuel trims of -3%, saying it had to take that 3% of fuel away. BUT instead, the ecu is reporting that it still had to add more fuel (i.e. your LTFT=+4%). Just doesn't make sense to me at all.

My recommendation would be to return the low safc settings back to zero since you have the stock injectors. Run it for a few days (to let the LTFTs get used to the new safc settings) and then relog STFT, LTFT, throttle, rpm. Good luck.

 

[DCJ98GST]

The LTFT are adding fuel because he is flowing more air due to the turbo and other modifications. The ecu can adjust for more air in closed loop therfore it is adjusting the LTFT positive. This is normal.

 

[crashed97tsi]

ah ok, I was adjusting for the STFT. So, you want to make your main adjustments by the LTFT?

How about on the first log, where I'm getting my timing pulled. I want to richen up there, right?and maybe try a little bit leaner on the other rpm increments?

Thanks

 

[Blk_99gst]

Originally posted by DCJ98GST
The LTFT are adding fuel because he is flowing more air due to the turbo and other modifications. The ecu can adjust for more air in closed loop therfore it is adjusting the LTFT positive. This is normal.

You've got to be kidding me right ! I'm sorry and not to be mean, but you really don't know tuning at all...

First off, we're talking short term and long term fuel trims and when talking about those values, we're talking about low safc settings, and low safc settings is using 30% or less throttle. At 30% throttle your engine is under vacuum; aka it's not getting ANY boost from the turbo. It wouldn't matter if you had a t25 or an fp red on there; either one you tune low-safc settings the same way since the turbo does NOT come into play.

Read up a lot more about tuning...

 

[Blk_99gst]

Originally posted by crashed97tsi
ah ok, I was adjusting for the STFT. So, you want to make your main adjustments by the LTFT?

Yep. STFT will give you a quick indication on how things are changing. But LTFT are what you what to change your safc values by. And as always, you should only be doing this after your car is at proper operating temperature. And give the LTFT a day or so to reset after you make safc changes. Don't expect them to react immediately.

Originally posted by crashed97tsi
How about on the first log, where I'm getting my timing pulled. I want to richen up there, right?and maybe try a little bit leaner on the other rpm increments?
Thanks

I'm not a full on expert at tuning the high-safc settings, but this is what I think.

RPM TPS TIMING O2
3624 97% 10 .92v
3832 97% 10 .92v
4036 97% 11 .94v
4260 97% 12 .94v
4480 97% 11 .94v -Fallin, might richen up % or 2
4688 97% 11 .94v
4920 97% 11 .94v - Timing staying flat, not
5144 97% 11 .94v - advancing. Probably due more
5360 97% 11 .94v - to using the stock injectors.
5556 97% 13 .94v
5772 97% 14 .94v
6008 97% 14 .94v
6172 97% 17 .94v
6388 97% 15 .92v -Falling again, and o2 went down,
6552 97% 15 .94v -richen up 6388 a % or 2.
6712 97% 16 .94v
6868 97% 16 .94v
7032 97% 16 .94v
7164 97% 17 .92v

What's your max egt's at the end of the run? And is this 2nd or 3rd gear; looks like a 2nd gear. I would log 3rd gear pulls; 2nd gears go by too quick.

 

[nine5raptor]

Originally posted by Blk_99gst
Now what totally doesn't make since to me is that you have the stock injectors and if you had the low settings set to zero on the safc, then it would act like the safc wasn't even in the system (normally stock car). I would think by you having a +3% safc settings, that the ecu would have long term fuel trims of -3%, saying it had to take that 3% of fuel away.

Everycar will be different. I would think very few would actually be at 0% even stock. Tolerances in machining the throttle bodies, intake mani's, valves, as well as slight differences in mass airs, air leaks... will all change these. That is why they are there in the first place, to compensate for differences.

My ltft was 17% completely stock. I now have it at 10%, but can't get it to go lower.

I use a maft, so my settings are as follows,
base 0% correction (stock 450's)
idle +20% fuel (-20% air for you afc guys)
mid -10%
wot -10%
sound ####ed up? these give me the best timing.

 

[crashed97tsi]

My max egt's at the end of the run are anywhere from 1500-1550. It has never gone higher than that. The runs are 3rd gear pulls.

Thanks

 

[candela]

Blk99 is right...

Yep. STFT will give you a quick indication on how things are changing. But LTFT are what you what to change your safc values by. And as always, you should only be doing this after your car is at proper operating temperature. And give the LTFT a day or so to reset after you make safc changes. Don't expect them to react immediately.

I would wait a little longer or shorter depending on driving conditions. You can watch and see the ST to see whats up. As for the LTFT I would wait a while as driving conditions will always vary and the ECU needs to see different temps, elevations, TPS's...etc So maybe a day is good, maybe 3 is better. Don't bust yoruself about this though my man. 14psi on a 190 rewired walbro... I would just leave everything alone and let the ecu take over completely in this case. If you really want to tune it then I would honeslty try leaning it up a bit instead of richning. I know how to tune my car period, as we all know everycar is different. but running more than .94 on 93 octane at only 14psi (regardless) is prolly a bit rich. is your o2 sensor up to par? After you tihkn you have yoru low throttle setting done try holding a steady idle and watch yoru realtime o2 values. Then lean it out enough so the o2 stops oscillating and then go slowy (the ecu needs to react) in incrememnts of w/e you feel comfortable with richining until it starts cycling again. When it does check your low settings in conjuntion with what you had before and your STFT... For me 100% worked great if I just bumped it up about 2-3% (bare in mind this is with the old 550's) past the point of when it starts cycling again. I have since been just tuning my 660's, VPC, AFC using this method and dynoed and found that with this by myself I kept a pretty smooth curve around 13.5:1 A/F ratio (off boost ofcourse)....

 

[crashed97tsi]

Thanks for the help guys, I learned alot more from this thread and I actually have the hang of it now. I took candela's advice and just zeroed out the low settings. I have 550's on the way now so I'll play with the low settings more once I have a reason to play with them. The car is definetly pulling harder than it was before, so I guess the little differences in the high setting made a difference.

edit: one last questions. When I get the 550's should I reset the ecu to clear all the fuel tables?

Thanks Again
Dan

 

[nine5raptor]

no. it will take longer for them to relearn them completely than it would to just adjust them slightly. plus, if the afc is tuned correctly, the trims will remain nearly identical to where they are now, with the afc doing the rest of the adjusting.