It seems that all the engine management units require you to adjust various settings to acheive a certain AF ratio. Isn't there anything that allows you to enter your desired AF ratio at given RPMs and makes the necessary readings and then adjustments to maintain that AF ratio? Or is that already how it is and I have just been smoking crack? I would assume you would need an engine management system capable of reading its own built in wideband O2 system. Granted, if that's correct, it would cost a little more, but wouldn't it be worth it?

 

I'm not familiar with any but you should invent it. You'd make a killing! lol, no well theres a few reaons why its not like this. First of all, taking a reading, using basic piggyback fuel management wont be reading from a wide-band o2, however it will be reading o2 (if it does) off of your o2 sensor, which is like the Air/Fuel ratio gauges (not the greatest accuracy). Meaning its judgements could be off. And if theres any doubt, there could be disaster.

All that I'm familiar with, APEXi, HKS, Greddy, etc. Use percentage adjustments to either the air fuel ratio or injector duty cycle to adjust mixtures. One thing is, in order to tune these units you should always have a wide-band o2 for the best results and greatest accuracy.

 

I know what needs to be invented!!!

An O2 sensor that simulates a NB sensor that tells the stock ECU that it's at stoich when it really is reading whatever AF ratio you desire. It would fool the ECU into thinking it's at stoich when in reality you're running a perfect rich FI fuel mixture.

OK, gauntlet is down, now someone go build it.

 

Tadish semi hinted at this as part of the RT Cat flash he uses. I would buy it if I needed it. I guess by "hinted" you have to have talked to him to understand because he sort of thinks as he talks. Like," well yeah the RT cats don't seem to act like other cats do and my program fixes that but...."

I am like, well you mean they have no pre cat,

"you see yeah we can fix you right up, yeah no precats just the RT's though makes me think (then he starts thinking even deeper lol.)

But yeah, good idea.

 

There are some higher end engine management systems, for example Motec, that allow input from a wideband sensor to be used for feedback. This feedback is used to adjust fuel delivery while under heavy loads as needed.

Not all systems have this capability, and its an option on the Motec (not sure about others). The stock ecu does not have this capability, even with a reflash.

 

Now that I think about it though my NB O2 sensor wouldn't be that great anyways because the stock ECU ignores the O2 sensor in open loop anyways which is when it would really need that feedback. Oh well, guess I'm not gonna make my millions today.

 

Well, you could force it to run closed loop all the time, and let it try to control to what it thinks is stoich. But there are other problems with that. You'd also be running too rich at light loads, which wouldn't be good. Of course, you could devise a variable signal based on boost pressure, so at light loads the signal voltage would be "normal", and as boost increased the signal was modified. In reality, the dynamics of it would be too much to deal with I think.

 

Yeah, agreed.

Sorry to get off topic, but did you know that your J&S unit has the ability to force your engine into open loop by tying the TPS to 4.3Volt

I honestly don't know how that will effect our drive by wire car, but maybe someone with a better insight into our ECU could answer that.

In other less sophisticated cars this would just cause the engine into open loop, but I'm wondering if doing this on our car would actually physically open up the throttle.

 

Yep...I'm already considering that. Still need to research it more...I hate drive by wire.

 

Let me know what you find out.