need help with SAFC, cant find good answer

[adrian2627]

i know im a newb and that i should search first. I tried that a couple of times but couldnt get a reliable, straightforward answer. I have a couple of questions in regards with tuning:
1. i have a 98 gsx and currently have 560cc evo8, 255lph,fmic,SAFC, e3b16g. I cant get a stable smooth idle. i tried adjusting the trims but still the same. Sounds like its misfiring/sputtering/popping. I already changed the plugs and wires, all vacuum hoses connected, maf not altered. But everything throughout the entire rpm band is smooth.
2. This is my first attemp on tuning with a logger and SAFC, ive read all the posts about begginers guides from dsmtalk and tuners, i followed them and i think i have an ok tune (well it runs ) i cant get a smooth timing curve, i see 3,5,6,9,4,6,3...etc. on the log, no negatives though. Also i dont think im running lean according to the logger, my graph stays about the middle line on the middle line.
3. Do i add fuel or take fuel to specific rpms to increase timing? also on part throttle my timing is kinda high (round 30 +/- 5) then when i get on it, it will go down to single digits but never negative.
4. SORRY FOR MY POST BEING TOO LONG, JUST REALLY NEED HELP SINCE THIS IS MY DAILY DRIVER AND ALL. AGAIN SORRY AND THANKS IN ADVANCE!

 

[adrian2627]

Time,RPM,Timing,Airflow,O2 1 Bank 1,O2 Trim 1 Bank 1
00:01.14,2875.0,30.0,3.31,0.04,-2.34
00:01.38,2887.0,28.0,3.68,0.04,0.78
00:01.61,2914.0,27.0,4.08,0.06,3.91
00:01.83,2914.0,26.0,4.34,0.06,7.03
00:02.06,2945.0,25.0,4.63,0.1,10.16
00:02.29,2980.0,24.0,5.02,0.48,13.28
00:02.52,3008.0,24.0,5.52,0.7,14.06
00:02.76,3035.0,24.0,5.82,0.3,12.5
00:03.22,3102.0,24.0,6.16,0.22,13.28
00:03.46,3141.0,21.0,6.98,0.7,14.06
00:03.69,3168.0,20.0,7.43,0.62,11.72
00:03.92,3207.0,18.0,7.9,0.76,13.28
00:04.15,3262.0,16.0,8.49,0.64,11.72
00:04.38,3301.0,16.0,8.98,0.18,10.94
00:04.61,3344.0,15.0,9.73,0.84,0.0
00:04.84,3402.0,12.0,10.45,0.84,0.0
00:05.07,3438.0,10.0,11.27,0.86,0.0
00:05.30,3508.0,11.0,11.99,0.88,0.0
00:05.76,3707.0,10.0,13.3,0.88,0.0
00:05.98,3992.0,10.0,14.13,0.88,0.0
00:06.21,4172.0,10.0,15.41,0.88,0.0
00:06.46,3875.0,15.0,5.57,0.92,-0.78
00:06.69,3742.0,31.0,6.73,0.62,0.0
00:06.92,3797.0,17.0,11.4,0.88,0.0
00:07.15,3852.0,13.0,12.94,0.9,0.0
00:07.38,3898.0,10.0,14.46,0.92,0.0
00:07.61,3965.0,9.0,15.86,0.92,0.0
00:07.84,4012.0,9.0,15.58,0.9,0.0
00:08.06,4063.0,10.0,16.08,0.9,0.0
00:08.30,4125.0,10.0,16.13,0.92,0.0
00:08.52,4168.0,10.0,16.5,0.92,0.0
00:08.76,4227.0,10.0,16.36,0.92,0.0
00:09.22,4336.0,10.0,16.82,0.92,0.0
00:09.46,4387.0,10.0,17.39,0.92,0.0
00:09.68,4441.0,9.0,17.62,0.92,0.0
00:09.92,4500.0,10.0,17.74,0.92,0.0
00:10.38,4582.0,10.0,18.31,0.92,0.0
00:10.60,4625.0,11.0,18.43,0.92,0.0
00:11.06,4738.0,11.0,18.55,0.92,0.0
00:11.28,4797.0,11.0,19.1,0.92,0.0
00:11.52,4855.0,12.0,19.33,0.92,0.0
00:11.76,4891.0,11.0,19.55,0.92,0.0
00:11.98,4926.0,11.0,19.69,0.92,0.0
00:12.22,4965.0,12.0,19.82,0.92,0.0
00:12.46,5031.0,12.0,19.84,0.92,0.0
00:12.92,5121.0,12.0,20.12,0.92,0.0
00:13.14,5156.0,13.0,20.13,0.92,0.0
00:13.38,5195.0,14.0,20.21,0.92,0.0
00:13.60,5242.0,14.0,20.35,0.92,0.0
00:13.84,5277.0,14.0,20.24,0.92,0.0
00:14.30,5367.0,14.0,20.44,0.92,0.0
00:14.52,5414.0,15.0,20.34,0.92,0.0
00:15.00,5504.0,16.0,20.64,0.92,0.0
00:15.44,5566.0,16.0,20.83,0.92,0.0
00:15.68,5598.0,17.0,20.86,0.92,0.0
00:16.13,5676.0,17.0,21.07,0.92,0.0
00:16.37,5715.0,18.0,20.99,0.92,0.0
00:16.81,5781.0,17.0,21.15,0.92,0.0
00:17.04,5813.0,17.0,21.36,0.92,0.0
00:17.29,5855.0,17.0,21.47,0.92,0.0
00:17.53,5891.0,17.0,21.58,0.92,0.0
00:17.76,5918.0,18.0,21.6,0.92,0.0
00:17.98,5957.0,19.0,21.53,0.92,0.0
00:18.21,5977.0,19.0,21.89,0.92,0.0
00:18.45,6008.0,19.0,21.93,0.92,0.0
00:18.69,6047.0,19.0,22.03,0.92,0.0

 

[Rice Over Wheat]

The tech guides on tuning don't explain a lot of things. I'm also learning to tune and asked a lot of these same questions.

Ignore timing at part throttle. When cruising it will always be high around 25 to 33 or so. That's because it uses different timing maps. At WOT timing should drop to single digits and scale up with rpms to ideally around 22. And drops on the way up means it's getting pulled to compensate for knock counts. When you see pulled timing you want to add (richen) a % or two at that rpm, then try another pull and see how it changes. When you have a nice smooth timing curve under WOT you can try adding a psi or two of boost and see if you can still tune out the knock by adding fuel where you need it.

 

[Gromit]

i know im a newb and that i should search first. I tried that a couple of times but couldnt get a reliable, straightforward answer. I have a couple of questions in regards with tuning:
1. i have a 98 gsx and currently have 560cc evo8, 255lph,fmic,SAFC, e3b16g. I cant get a stable smooth idle. i tried adjusting the trims but still the same. Sounds like its misfiring/sputtering/popping. I already changed the plugs and wires, all vacuum hoses connected, maf not altered. But everything throughout the entire rpm band is smooth.
2. This is my first attemp on tuning with a logger and SAFC, ive read all the posts about begginers guides from dsmtalk and tuners, i followed them and i think i have an ok tune (well it runs ) i cant get a smooth timing curve, i see 3,5,6,9,4,6,3...etc. on the log, no negatives though. Also i dont think im running lean according to the logger, my graph stays about the middle line on the middle line.
3. Do i add fuel or take fuel to specific rpms to increase timing? also on part throttle my timing is kinda high (round 30 +/- 5) then when i get on it, it will go down to single digits but never negative.
4. SORRY FOR MY POST BEING TOO LONG, JUST REALLY NEED HELP SINCE THIS IS MY DAILY DRIVER AND ALL. AGAIN SORRY AND THANKS IN ADVANCE!

No AFPR? I didn't see 1 in your profile & you didn't list 1 with your mods in this post. If you don't have 1, that's why you're having problems at idle - that 255 lph fuel pump is overrunning your stock FPR & makes tuning the fuel trims near impossible. A search on this site will lead to tons of threads on this topic & suggestions for what AFPR to buy. Get this resolved 1st & then you can move onto WOT tuning.


EDIT: Here's a link to a tuning guide in case you haven't already checked it out - it'll tell you all about tuning FT's & then moving on to WOT tuning. http://www.racingknowledge.org/ver3/...pic.php?t=1011

 

[adrian2627]

hey thanks guys! rice's explanation really drops it down barney style that made a lot of sense. i bought the car from another guy thats why i didnt know about the walbro thing till a couple of searches yeilded that the 255 will outrun the fpr. that wil be next on my buy list. also so pretty much thats the basics? set my base trims for wot, do a pull and look at the logs, timing curve should be smooth going up starting from single digits going to bout 20+, then look for timing pulls around the band and add fuel accordingly, then do a run again and if satisfied then try turning up boost a lil and start over.

one more thing though, i set my NE points like this: 1000,1400,2000,3000,4000,4400,5000,5400,6000,7000 is this correct? coz i figured, what if the dip in the timing drops around 5200 or somewhere within a thousand of 5 and 6, where do i add fuel? 5000 or 6000? hope you get it coz im having a hard time explaining myself. ! thanks again guys

 

[Gromit]

hey thanks guys! rice's explanation really drops it down barney style that made a lot of sense. i bought the car from another guy thats why i didnt know about the walbro thing till a couple of searches yeilded that the 255 will outrun the fpr. that wil be next on my buy list. also so pretty much thats the basics? set my base trims for wot, do a pull and look at the logs, timing curve should be smooth going up starting from single digits going to bout 20+, then look for timing pulls around the band and add fuel accordingly, then do a run again and if satisfied then try turning up boost a lil and start over.

one more thing though, i set my NE points like this: 1000,1400,2000,3000,4000,4400,5000,5400,6000,7000 is this correct? coz i figured, what if the dip in the timing drops around 5200 or somewhere within a thousand of 5 and 6, where do i add fuel? 5000 or 6000? hope you get it coz im having a hard time explaining myself. ! thanks again guys

Think of it this way - the correction factor at the 1k rpm Ne point is what is applied at rpm's below 1k - i.e., at idle. Continuing up from there, in your example with your specified Ne points, if the timing dipped at 5.2k rpm you would add fuel at your 5.4k rpm Ne point. The correction value at the 5.4k rpm point is what is applied between your previous point (5k rpm's) up to 5.4k rpm's. Also keep in mind that the SAFC interpolates between rpm points., i.e., if your correction factor at 3k rpm was -10% & your correction factor at your 4k rpm point was -20%, at 3.5k rpm the SAFC would apply an interpolated correction of approximately -15%.

 

[Rice Over Wheat]

Adrian it's impossible to set your fuel trims correctly with the Walbro255 on stock FPR. Just check out this log I posted to see how flooded I am:

http://www.dsmtuners.com/forums/showthread.php?t=245101

It's about useless trying to tune without an AFPR. I just got my Aeromotive AFPR today and am going to install it this hour. You should get one as soon as you can because you're missing a required component to run correctly, let alone tune.

Oh and if you have idle problems, try adding fuel at 1000 rpm. If you lean it out the car will start to run all rough and shaky, with the exhaust sounding irregular. Then if you richen it, things should smooth out and you'll hear the exhaust note change. Adjust your amoung of fuel at 1000 rpm so that you idle smooth on the bigger injectors. On 560s your baseline is around -10% to -15% so your 1000 rpm point may end up sitting around -2% to -7% I'm guessing, in order to idle smooth.

 

[Gromit]

Adrian it's impossible to set your fuel trims correctly with the Walbro255 on stock FPR. Just check out this log I posted to see how flooded I am:

http://www.dsmtuners.com/forums/showthread.php?t=245101

It's about useless trying to tune without an AFPR. I just got my Aeromotive AFPR today and am going to install it this hour. You should get one as soon as you can because you're missing a required component to run correctly, let alone tune.

Oh and if you have idle problems, try adding fuel at 1000 rpm. If you lean it out the car will start to run all rough and shaky, with the exhaust sounding irregular. Then if you richen it, things should smooth out and you'll hear the exhaust note change. Adjust your amoung of fuel at 1000 rpm so that you idle smooth on the bigger injectors. On 560s your baseline is around -10% to -15% so your 1000 rpm point may end up sitting around -2% to -7% I'm guessing, in order to idle smooth.

As you mentioned, it's useless to try to tune without the AFPR, & that includes trying to get the idle tune correct. With the 255 lph pump the stock FPR is being overrun at both idle & at low-throttle cruise. It's a vicious cycle & near impossible to get a consistent fuel trim at idle. Richening it up will seem to work initially & then after driving it for a bit it'll seem like it needs to be leaned out. The ECU just can't keep up since the fuel delivery is unpredictable. Unless the original poster has a highly negative SAFC setting at 1k rpm right now, he would more likely be rich rather than lean at idle, given the larger injectors & the lack of AFPR.

For the original poster, keep in mind that those EVO 560 injectors typically flow more like 580's. Your baseline correction factor for 560's would be approx. -19% for the HI Throttle map, but if they flow more like 580's then it would be closer to -22%.

Also, how's your O2 sensor cycling at idle?

 

[adrian2627]

thanks for the replies! My o2 sensor will cycle slowly between lean and stoich. Im at -20 right now on my 800rpm correction and around -21/-20 accross the board on low. When i got my lows semi tuned and running ok, i went ahead and tried tuning the highs, i came up with -25 on 3000, -29 the rest. I logged a run and i came up with good o2 readings (not lean, around 0.85 - 0.94, it varies) then i looked at the timing curve and it starts from single digits like 8/9 then slowly rises to around 20 +/- 3. thats at 15 psi. i have an EBC so im trying to tune my low boost at 15 then high boost at around 19.

 

[adrian2627]

im definitely going to get an AFPR, im still waiting for next payday also, i do have a walbro 190 laying around, would it be wise to use that for the mean time rather than sticking with the 255? also will that support my goals (19PSI?) thanks again

 

[spyderturbo007]

im definitely going to get an AFPR, im still waiting for next payday also, i do have a walbro 190 laying around, would it be wise to use that for the mean time rather than sticking with the 255? also will that support my goals (19PSI?) thanks again

Nah, just keep the 255 in there until you get the AFPR in a couple of weeks. You are just going to be screwing your gas mileage and you WOT tune until you hit about 6 or 7psi. Not enough of a problem worth swapping fuel pumps 2 times.