My tune....
Thread Starter
Le Mans Master
Joined: Oct 2001
Posts: 5,577
Likes: 3
From: Southern Maryland Maryland
My tune....
I have been a dog chasing its tail for the last 2 weeks trying to get this tune right. Initally I tuned the car with some bad tables. After I switched back to the stock tables and recalculated a couple of others I went back to VE Tuning in SD mode. A couple of days passed and after 3-4 drives the car was +-3% error in almost every cell. I went back to non SD tune and the car ran like garbage, the LTFT were off and the car wanted to break up for some reason. Looking at the logs the MAF data was corrupt. The data was all over the place. We pulled the MAF and sure enough it was dirty.
I cleaned the MAF and went back to SD tune to make sure it was right and it was dead on. So the next tune I used all of the data from the past 8 sessions to create a scatter chart to plot the corrected MAF data and sure enough the orginal tune was off. I uploaded the program with the calibrated MAF up to ~8500 and the car idles and drives like a champ. There is a noticeable difference in part throttle to WOT transition, part throttle 1200-1600rpm driving(no surging), and all of the trims are +-1. Now we need to go back and tune the car to WOT. If you guys got any questions let me know.
Phil
I cleaned the MAF and went back to SD tune to make sure it was right and it was dead on. So the next tune I used all of the data from the past 8 sessions to create a scatter chart to plot the corrected MAF data and sure enough the orginal tune was off. I uploaded the program with the calibrated MAF up to ~8500 and the car idles and drives like a champ. There is a noticeable difference in part throttle to WOT transition, part throttle 1200-1600rpm driving(no surging), and all of the trims are +-1. Now we need to go back and tune the car to WOT. If you guys got any questions let me know.
Phil
Racer
Joined: Aug 2003
Posts: 290
Likes: 8
From: 60 miles from BGKY
Originally Posted by Phil97SVT
I have been a dog chasing its tail for the last 2 weeks trying to get this tune right. Initally I tuned the car with some bad tables. After I switched back to the stock tables and recalculated a couple of others I went back to VE Tuning in SD mode. A couple of days passed and after 3-4 drives the car was +-3% error in almost every cell. I went back to non SD tune and the car ran like garbage, the LTFT were off and the car wanted to break up for some reason. Looking at the logs the MAF data was corrupt. The data was all over the place. We pulled the MAF and sure enough it was dirty.
I cleaned the MAF and went back to SD tune to make sure it was right and it was dead on. So the next tune I used all of the data from the past 8 sessions to create a scatter chart to plot the corrected MAF data and sure enough the orginal tune was off. I uploaded the program with the calibrated MAF up to ~8500 and the car idles and drives like a champ. There is a noticeable difference in part throttle to WOT transition, part throttle 1200-1600rpm driving(no surging), and all of the trims are +-1. Now we need to go back and tune the car to WOT. If you guys got any questions let me know.
Phil
I cleaned the MAF and went back to SD tune to make sure it was right and it was dead on. So the next tune I used all of the data from the past 8 sessions to create a scatter chart to plot the corrected MAF data and sure enough the orginal tune was off. I uploaded the program with the calibrated MAF up to ~8500 and the car idles and drives like a champ. There is a noticeable difference in part throttle to WOT transition, part throttle 1200-1600rpm driving(no surging), and all of the trims are +-1. Now we need to go back and tune the car to WOT. If you guys got any questions let me know.
Phil
My 98 has a stock MAF, but it turns out to have the Monaro's curve. If I hadn't been building this curve as I SD tuned, the STFT's would have skewed when I reenabled the MAF. Like you, I have a sweet part throttle tune and hardly had to touch anything PE-wise to get good WOT power with almost no KR at the dyno. Made a believer out of me.
Instructor
Joined: Jun 2004
Posts: 207
Likes: 0
Thanks Phil! Can you post your VE table? I'm curious what it looks like. Also while in open loop SD mode how do you dial in the VE table at high RPM values if they say to keep it under 4k?
When you state calibrated MAF, do you mean the MAF tables you just tuned or do you mean an aftermarket MAF unit?
When you state calibrated MAF, do you mean the MAF tables you just tuned or do you mean an aftermarket MAF unit?
Racer
Joined: May 2004
Posts: 377
Likes: 3
From: Marietta GA
slo-vette, by calibrating the MAF, he means that he logged the MAF hz and the Dynamic Airflow PIDs and then used that data to get the MAF hz table inline with correct reading. For each Hz the MAF reads, it translates that into x.xx amount of air it read. Now if that table is off, then the MAF is incorrectly reporting the air. So calibrating to the closest possible value is key.
Dixit
Dixit
Thread Starter
Le Mans Master
Joined: Oct 2001
Posts: 5,577
Likes: 3
From: Southern Maryland Maryland
Couple of things..
1) You dont need a MAF to SD tune
2) Marcin's calculator uses MAF frequency vs Dynamic Air(Averaged data)
3) I made pulls up to 7000 to tune the VE table and averaged the high end
4) My maf has custom ends on it that have been bored out to 90+mm
- Used the logged data MAF vs DA and used that data.
Phil
1) You dont need a MAF to SD tune
2) Marcin's calculator uses MAF frequency vs Dynamic Air(Averaged data)
3) I made pulls up to 7000 to tune the VE table and averaged the high end
4) My maf has custom ends on it that have been bored out to 90+mm
- Used the logged data MAF vs DA and used that data.
Phil
