Questions

Questions

Okay, im not a tech person. Im still learning about cars everyday it seems like. And id like to keep on learning more....

SAFC. I understand the concept behind them. But I heard of people using a "ROM tune" over an FC, mainly for Nissans. Nissan owners say its better for under 500rwhp. Honda people say "ROM tunes" messes up the ECU and could cause you to blow your motor. But at the same time, Honda and Nissan are two different things. I guess I can understnad why that would happen but why would someone explain why you would choose tuning your ROM over an SAFC??

Also, closed loop and open loop operation. I don't understand when other people try to explain it...elaborate on this too..

And what about this, need a wideband business...

Open loop and Closed loop refer to fueling method.

In closed loop fueling, the computer takes readings from the oxygen sensors and makes corrections to maintain Stoichmetric(sp) ratio, about 14.7:1 air/fuel.

In open loop, it doesn't use the sensors. Open loop is what is used when at WOT, the sensors are cold, whe starting the car, etc. The air/fuel ratio is usually fixed richer for drivability's sake until the parameters are met to begin closed loop operation.

At least, that's how it was explained to me.

^^that open and closed loop explanation sound about the same as what i was told too...

That's really all there is to it. Closed loop runs off the sensors, open loop runs off a preset value in the computer.

And for the wideband vs. narrowband O2. I don't have anything I race that has an ECU per se, but I do have an Innovate wideband I'm installing on the 83 so I'll try. A narrowband O2 can tell you when you've reached 14.7:1 a/f ratio. It can tell you if you're lean or rich, but it can't tell you by how much. A wideband measures a wider range of a/f ratios so it can tell you exactly where you are(within its parameter) as far as being rich/lean goes.

If someone who knows the truth fo sho and sees that I'm wrong somewhere, feel free to correct it.

^^that seems pointless to have a narrowband O2 then...unless of course it comes that way stock..are there any advantages of having this narrowband then??

A vehicle that is basically stock will do fine on a regular ass O2 sensor. When you start adding things like forced induction, nitrous, or have a high compression aspirated application, you'd want to run a wideband. For the vast majority of bolt on modifications like intake/header type stuff, the computer can adjust A/F ratio on its own enough to compensate for the extra air coming in. Hence why after the installation of a CAI, you tend to get a couple MPG less than before.