Stocky
25-07-2009, 04:55 PM
Thought some of you might like to see this.
Below is a screen shot of some data logged on my AFR Tuner.
I've got individual Lambda sensors in 3 of the header pipes (waiting for a 4th sensor to show up in the post)
I've added some labels to the shot to help it make sense.
What you are looking at is a roll on (some variation in throttle position) in 4th gear.
RPM is at the top in orange.
Throttle position is in the middle in blue
Then the individual A/F ratios of each cylinder are shown in Red at the bottom.
For arguments sake, lets say the target A/F is 13:1 (good power and fast acceleration)
The Red scale goes from 12:1 to 14:1
http://www.asfphotos.com/upload/1248504461.jpg
So.....
Over all it's a bit lean (more than a bit actually)
You can see it in this shot but it's more evident in other parts of the data that the variation (and the actual A/F) vary more at part throttle than full throttle.
This engine made 182HP at the back wheel at Casino. The tune at 100% is pretty good.
However, at anything but full throttle it's all over the place.
The funny thing is, the fueling at part throttle feels fantastic.
The data above is also with some tuning of individual cylinders already done (not much though)
In a min I'll post up an example of the cylinder offsets so far....
Below is a screen shot of some data logged on my AFR Tuner.
I've got individual Lambda sensors in 3 of the header pipes (waiting for a 4th sensor to show up in the post)
I've added some labels to the shot to help it make sense.
What you are looking at is a roll on (some variation in throttle position) in 4th gear.
RPM is at the top in orange.
Throttle position is in the middle in blue
Then the individual A/F ratios of each cylinder are shown in Red at the bottom.
For arguments sake, lets say the target A/F is 13:1 (good power and fast acceleration)
The Red scale goes from 12:1 to 14:1
http://www.asfphotos.com/upload/1248504461.jpg
So.....
Over all it's a bit lean (more than a bit actually)
You can see it in this shot but it's more evident in other parts of the data that the variation (and the actual A/F) vary more at part throttle than full throttle.
This engine made 182HP at the back wheel at Casino. The tune at 100% is pretty good.
However, at anything but full throttle it's all over the place.
The funny thing is, the fueling at part throttle feels fantastic.
The data above is also with some tuning of individual cylinders already done (not much though)
In a min I'll post up an example of the cylinder offsets so far....