Quote:
Originally Posted by Darkshot About how many tenths of a second does it take for a PW adjustment to make it through the engine and register on the WB? |
It can take quite a while. Starting from the beginning, with 80Hz loops in the ECM that is a maximum of 12.5 msec for the ECM delay. This is the time between when an AE event is seen and queued up for injection. Note that this is for synchronous AE injection.
With a TBI system an injector fires every time a cylinder fires. This gets tricky as this means that at firing time another cylinder is halfway (90 deg) through the intake stroke. With the next in line at the beginning of the intake stroke (I am ignoring cam timing such as intake opening BTDC and closing ABDC).
The transport delay through the engine is dependent upon RPM. At 1,000 RPM it takes 120 msec from an intake to intake event on a single cylinder. At 2,000 RPM that becomes 60 msec.
Usually once over 2,000 RPM the need for AE tapers off (intake velocity reduces wall wetting).
With the engine starting to exhaust prior to the intake stroke, that time can be made at 3/4's of a full cycle. Or 90 msec at 1,000 RPM and 45 msec at 2,000 RPM. With it extending to the full cycle time to complete the exhaust stroke (120 & 60 msec).
A WB sensor can easily lag another 200 to 250 msec. There will also be some lag in the WB controller. This would be dependent upon the level of filtering and the firmware update rate.
There is then the time it takes to travel out the port and down the exhaust pipe.
Worse case at 1,000 RPM for just the values I listed is: 12.5 + 120 + 250 = 382.5 milli-seconds. Or over 1/3 of a second.
RBob.