View Single Post
Old 09-08-2008, 10:47 AM   #12 (permalink)
EcoModding Lurker
Join Date: Aug 2008
Location: Massachusetts USA
Posts: 84

Ziggy - '95 Audi S6 Sedan

Manfred - '97 Audi A6 Quattro Sedan
90 day: 20.61 mpg (US)

Clarabell - '03 Audi A4 Quattro Avant

Sherman - '98 Audi A6 Quattro Avant

Cab - '96 Audi Cabriolet
Thanks: 0
Thanked 2 Times in 2 Posts
I did some logging on the way home last night. At 75 mph, the engine is turning 3400 rpm and burning 22 mpg (my guesstimate). Here's the injector pulse width at that speed:

This one happens to be 550 micro seconds width. I logged a number of these and the average is around 562 uS.

For my 2.8 liter 12 valve V6, I calculate 100,890,240 uS per gallon. Once I get this installed and running we'll see how accurate that is.

BTW: I'm using a sound card oscilloscope program on my laptop to capture the signals. I have an audio cable connected to the car with a couple of resistors to drop the signal voltage below 1V. It's plugged into my laptop microphone input. Works just fine at the frequencies we're dealing with.
  Reply With Quote