Conflicting opinions on tuning – Just lay it out please
Do you see the AFR/load comparisons I'm talking about? As the AFR becomes closer to 11.1, the power comes up. As it continues to drop into the 10 range, power falls. Even during the rise and falls of power, you can see that AFR changes one way or the other have an effect on what the power does.
Here is my biggest problem right now and I need to stop doing it, when I make change to my AFR map and go log if I am still running rich I make fuel trim changes with the MAFT and then do some more logs note what settings I used for that run. Then I come home and try to make changes to the high oct fuel map, flash and try again.
My goal is to get the MAFT zeroed out and use the ECU for 100% of the fuel trim tuning. But it’s been a slow going process due to the fact I am no pro at tuning and the temptation to reach over and grab the MAFT to fix settings in a live environment is working against me as you can see by the un stable AFR readings.
So now I am getting ready to go out and zero out the maft again and get some logs but I have done this before and I was running in the 10's and 9's and the car would cut under boost. I have an xls AFR calculator when I enter the logged value then the mapped value and my target value and gives me the new value to enter into the map. Ill just use that and re work my high oct fuel map with the MAFT zeroed out all the way.
So let me ask you some more questions. What should my AFR be when building boost? How do I control how much inj duty cycle is being used, timing?
Thx again
Last edited by BCOZEVO; Jan 2, 2008 at 09:36 AM.
Do you see the AFR/load comparisons I'm talking about? As the AFR becomes closer to 11.1, the power comes up. As it continues to drop into the 10 range, power falls. Even during the rise and falls of power, you can see that AFR changes one way or the other have an effect on what the power does.
Ok I went and zeroed my MAFT out then did a pull in 3rd. It was not 2 bad with the AFR map I have right now but if you look at the log on line 48 I hit some kind of boost cut or something because my car just lost power for a sec then picked back up. Why?
Thx
Thx
Aim for ~12.5:1 till you get to around 180 load, then drop to around 11.5:1.
Your IDC% is directly related to your AFR, RPM and boost ... timing is completely unrelated. At a given AFR, the IDC% will increase with increased boost or RPM. Higher boost means more O2 and that requires more fuel to keep the required AFR. Higher RPM means that you have to spray the same amount of fuel in a shorter time, so the IPW increases to accommodate.
Lower your IDC% by lowering boost, leaning out the fuel mix or changing hardware (pump, regulator or injectors).
Your IDC% is directly related to your AFR, RPM and boost ... timing is completely unrelated. At a given AFR, the IDC% will increase with increased boost or RPM. Higher boost means more O2 and that requires more fuel to keep the required AFR. Higher RPM means that you have to spray the same amount of fuel in a shorter time, so the IPW increases to accommodate.
Lower your IDC% by lowering boost, leaning out the fuel mix or changing hardware (pump, regulator or injectors).
I also add my mivec map. Mivec affects AFR, so it is better to addjust mivec before AFR. If you do it the other way, then yopu will have to adjust AFR again.
The second step is to adjust the boost. Adding boost also moves you higher in the load cells and that makes your AFR richer on the stock fuel map. So you are wasting time adjusting the AFR map before the boost since you will have to do it again.
After setting the proper boost, I set the AFR A 11.7-11.5 peak and then tapering to 11:1 by redline.
At the very end, I advance the timing until I encounter knock and then back it off by 1* and leave it there.
Last edited by nj1266; Jan 2, 2008 at 05:13 PM.
Mine actually does that occasionally, I always just wrote it off as a glitch in the matrix.
Mine always, after really looking at his log, replicates the same as his, a serious drop in the "Airflow" column as well.
But, upon further investigation, his injector duty cycle also dropped a bit too, along with the LoadCalc & 2Byte Load, AFR also jumped up to 15.9 which makes sense given the boost is the same.
My car more or less will occasionally do this, but I don't see the drastic jump in AFR. I wonder if the car just "Hiccupped" for a second. I am surprised that you don't see any knock there when the car did this.
You can probably get a little bit of power out of the car by getting your AFR's up a little on the second 100% throttle run. Very low 10's is a little too rich for my blood. But, that's just me.
Last edited by tkklemann; Jan 3, 2008 at 04:02 AM. Reason: Sphelling.
The 4th gear part of the log gets way too rich after 6000 rpm. You can fix that by making the target AFR values that your hitting in 3th gear the same as the target AfR values that you are hitting in 4th gear.
Last edited by nj1266; Jan 5, 2008 at 11:07 PM.
Your AFR spikes at the tail end of the 3rd gear pull. It is 11.3 @ 6750 and then it spikes 11.8 by 7125 rpm. Get it fixed and let it taper to 10.9 by 7500 rpm.
The 4th gear part of the log gets way too rich after 6000 rpm. You can fix that by making the target AFR values that your hitting in 3th gear the same as the target AfR values that you are hitting in 4th gear.
The 4th gear part of the log gets way too rich after 6000 rpm. You can fix that by making the target AFR values that your hitting in 3th gear the same as the target AfR values that you are hitting in 4th gear.
Right now I am running 98 oct (its a 93-115 oct mix). So thats why my numbers are kind of up at the end.
I was thinking since I am running such a high oct can I run 12.0 or is that pushing it? I use the 98 oct all the time, its on the pump at a gas station about half a mile from the house/track..
I was thinking since I am running such a high oct can I run 12.0 or is that pushing it? I use the 98 oct all the time, its on the pump at a gas station about half a mile from the house/track..
