quote:Originally posted by PanteraDoug: That's a very early system. Generally you need three inputs to make the program work. Oxygen sensor, TPS, MAP.
That would be a pretty crude set of inputs by today’s standards. However, some have achieved good results running IR EFI set ups with scheme’s as simple as just Alfa-N +RPM if the owners put the time into tuning under both controlled and road circumstances. If you have stable altitude and atmospheric conditions it can be sufficient but sort of depends on your engine specs, driving, and expectations. A big cam and a lot putting around town driving will require more effort to produce more civil street manners, but IR with good ECU and additional sensor schemes can be uniquely suited to do so. In closed loop most find that that O2 sensors aren’t very useful for much more than trimming idle and cruise, even with wideband O2 sensors. They are of course essential when it comes to emissions control if that is important to you. Things change too rapidly for closed loop O2 control to be very useful across the entire rpm range as far as performance goes for most street tuners. The race team’s set ups are much more sophisticated and can be a totally different story in this regard. I think wide band O2 is certainly useful input for tuning but position in the exhaust circuit and leaks can often create transient responses and false readings. For street driven IR, I’d recommend TPS, MAP, RPM, Inlet air Temp, Engine/Coolant temp, wide band O2, and maybe Idle Air Control (IAC), depending upon your control scheme. I’d also recommend that you run a crank trigger and gain full control of your ignition maps while you’re at it; why not have any advance curve for any set of conditions? Many of the modern ECUs have excellent subroutines that give you a great head start on schemes for idle, cold start/warm up, off-idle and enrichment schemes, etc. A lot of sensors and full control or fuel and ignitions MAPS means great potential for tuning but will also mean a lot of tuning to achieve the results. Be prepared to invest the time. Most find they can get to acceptable results fairly quickly and then just evolve and refine their schemes over time.
quote:There is the identical set up here on a wide fender car Dennis did and the car runs like do-do because it lacks an oxygen sensor. Glad yours works ok. Last I heard about the car here is it was being "revised" to include more inputs.
I’d say it’s either poorly sensored/equipped and/or tuned but the O2 sensor is probably the least of the issue if that is the case.
Best,
K