Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule #64
Posted: Mon Jan 10, 2022 4:45 am
https://datazap.me/u/scottsmith/2022-01-09-215459-v2?log=0&data=0-1-24-25-28-29
Seems steady at high rpm, choppy at low load. I'm not sure why 9.5s-12.5s has such high swings while 15.6s-20.7s has small swings. It's like it was caught in some sort of ringing/oscillation feedback and had to be pulled out of it to settle back.
If you look at the transitions to high RPM (time=21s and 28s), the high fuel pressure is steady, but low for a while. But at low RPM, the fuel pressure bounces all over the place. I think these two things together mean the peak angle is off. At high RPM the P term doesn't seem to have enough of an impact, but at low RPM the P term is having too much impact. If you look at the cam profile, you'll see that a small percentage delta at low load has a big impact in the # of degrees the pump is activated, but has less of an impact at higher loads. If we shift the peak position, then we'll be riding on a different part of the curve.
I don't want to keep fiddling with the P and I terms because I think the two load points are suggesting different changes. Really these should be set after getting the right peak angle.
Under Controllers/HPFP Cam Configuration, try a test with Angle of first lobe = 10 and = 20.
Seems steady at high rpm, choppy at low load. I'm not sure why 9.5s-12.5s has such high swings while 15.6s-20.7s has small swings. It's like it was caught in some sort of ringing/oscillation feedback and had to be pulled out of it to settle back.
If you look at the transitions to high RPM (time=21s and 28s), the high fuel pressure is steady, but low for a while. But at low RPM, the fuel pressure bounces all over the place. I think these two things together mean the peak angle is off. At high RPM the P term doesn't seem to have enough of an impact, but at low RPM the P term is having too much impact. If you look at the cam profile, you'll see that a small percentage delta at low load has a big impact in the # of degrees the pump is activated, but has less of an impact at higher loads. If we shift the peak position, then we'll be riding on a different part of the curve.
I don't want to keep fiddling with the P and I terms because I think the two load points are suggesting different changes. Really these should be set after getting the right peak angle.
Under Controllers/HPFP Cam Configuration, try a test with Angle of first lobe = 10 and = 20.