Tuning for low speed, very light throttle driving
Posted: Wed May 16, 2012 1:20 pm
Hi guys,
I've got my VE table pretty well sorted, but one area that I'm having trouble with is low speed (1500 - 2000 RPM) and very light throttle (1% - 5%) conditions. Think crawling through a parking lot. I can make things better by cranking in a lot of advance (40*), but then what winds up happening is that the car idles high sometimes because it gets "stuck" on the extra advance. If I keep the advance lower than the idle returns to normal idle (1050 RPM idle) much more quickly. With the extra advance it sometimes gets stuck at 2000 RPM. I've attached a tune file and recent log. Check out the 1600 and 2000 RPM cells at 0%, 1% and 3%. However, as the tune file sits today I was playing around with those areas so it may not be indicative of how I've been running it for the last few weeks.
The car is a 1973 BMW 2002 with throttlebody injection. The cam is fairly long duration at about 290*...
Any general tuning help is greatly appreciated!
Robert
I've got my VE table pretty well sorted, but one area that I'm having trouble with is low speed (1500 - 2000 RPM) and very light throttle (1% - 5%) conditions. Think crawling through a parking lot. I can make things better by cranking in a lot of advance (40*), but then what winds up happening is that the car idles high sometimes because it gets "stuck" on the extra advance. If I keep the advance lower than the idle returns to normal idle (1050 RPM idle) much more quickly. With the extra advance it sometimes gets stuck at 2000 RPM. I've attached a tune file and recent log. Check out the 1600 and 2000 RPM cells at 0%, 1% and 3%. However, as the tune file sits today I was playing around with those areas so it may not be indicative of how I've been running it for the last few weeks.
The car is a 1973 BMW 2002 with throttlebody injection. The cam is fairly long duration at about 290*...
Any general tuning help is greatly appreciated!
Robert