Rotary Injector Timing

[Dexter Alleyne]

 

Im having trouble understanding how to tune injector timing on rotaries. I’ve done as much research as I can and I can’t find all the details I need. I’m aware the end of injection is 180 degrees. However, the Link ecu instructions says to use the start of injection in order for the fuel cut function to operate correctly. On the base map, start of injection is 130 degrees. I’ve checked base maps from other ECU manufacturers and the injector timing are different on almost all of them.

 

 I’ve heard people say “Just keep playing with the timing until the engine is at its richest AFR and that’s the ideal timing.” Ok but is that at idle or 1500 RPM or what? I’ve read from other sources that the start of injection on a rotary happens at 440 degrees, yet the Link ECU will only let you set 360 degrees as the highest value. I’ve watched the Haltech rotary tuning video and they say start of injection is 270 degrees from idle to about 4,000 rpm then slowly increase to 330 degrees to redline. 

 

I’m in search of some solid advice because my concern is getting false AFR readings as a result of wrong injector timing. Basically fresh air and fuel being sucked into the exhaust then consequently blowing the engine. Thanks in advance. 

[Pete_89t2]

This post here might help you better understand injection timing on a rotary:

FWIW, I'm running the 130* injector timing figure from the Link S6/S7/S8 RX7 base maps in my single turbo 13B-REW FD and it's perfectly happy with that.