Quote: In the Sept 2010 edition of "Car Craft" under "whats your problem" they document a problem I've noticed for several years. A cammed engine will throw a wideband oxygen sensor off since the overlap can pass unburned fuel into the exhaust. I started out with a LM1 the LM2 and now run a Autometer wideband O2 sensor in my car. At idle it shows 16:1 (top of the scale) but the instant I touch the accelerator it jumps to 14:1. What this means is that any EFI that goes closed loop at idle is going to be riching the mixture to overcome this seemingly lean condition. This is why all EFI systems come with a preloaded map to get you started. My question on the EZ EFI or any other "learning" system, whats it gonna do at idle.
Good question. You can read lean at idle if you run open exhaust (common training issue for my race buddies) or if the cam has a lot of overlap.
In these situations with the XFI system I don't allow closed loop operation below an RPM where the O2 can be trusted.
The EZ-EFI system is not as user flexible, but it does limit what it does at idle - automatically (it knows the RPM and TPS). This handles the idle conditions of wild motors quiet well.
One last point on the 700 HP HEMI: A dual throttle body EZ will handle up to 1000 HP and the port injection EZ can handle up to about 800 HP. The reason the port injected is less, is that the injectors must be high-Z and it's hard to find high-Z injectors that are over 65 lbs/hr. The injectors used on the TB EZ are special made high-Z units.
