Quote:
Originally Posted by jmac
Is that your "burble" tune Dave?  |
Nothing intentional! Just over-run - happens when fueling changes rapidly such as going from deep throttle to lift-foot (or clutch-fuel cutoff) - excess fuel continues combustion into the exhaust system. Sometimes (like this photo) mixture in exhaust is too rich to burn until it reaches outside air and then has enough oxygen to burn. Kills mosquitoes as a side benefit....
I have tinkered with the calibration on how enters fuel-cut (either decel or clutch) - as well as rate of change of targeted fuel ratio and spark timing during these events to minimize burble - but can only do so much when going from ~800-900g/sec airflow to ~50-100g/sec in short order.
Makes cool photos though!
Dave