JeffBowlsby
Jun 22 2005, 10:02 PM
I stumbled on this chart of pulse widths courtesy of Brad Anders...Hopefully it is a starting point for anyone tuning an aftermarket FI ECU who also use stock injectors and fuel pressure.
0.1ms resolution is necessary.
The charts give data for PW based on manifold vacuum and RPM.
Stock 914 FI pulse widths
McMark
Jun 22 2005, 11:39 PM
Thanks, Jeff. I'll compare it next time I'm tuning.
SLKWrx
Jun 23 2005, 06:59 AM
I really wish I understood this stuff. Anyone have a page that helps explain how all this works?
Mueller
Jun 23 2005, 09:02 AM
this page explains it somewhat...you can ignore most of the math.....there is a little program on the page that allows you to plug in different variables and you can see the changes with different numbers...that might help
how Megasquirt works (basic EFI)
TravisNeff
Jun 23 2005, 10:17 AM
Hey that'd be one of my MPS in the chart, forgot about that. Brad is a good guy, he came over with his testers n' stuff and fixed a couple things on my 2.0 car. that saved me a ton of time and in the end probably a ton of money.
lapuwali
Jun 23 2005, 11:51 AM
Interesting bits of trivia here: the shortest pulsewidth is 2.3ms, which is longer than I've seen some settings shown here, even for smaller injectors. The longest duty cycle is 73%, which is well under the usual 80% ceiling noted for most injectors.