how accurate is the A/F ratio on the Apexi turbo timer?

[honda1982]

Does any1 no how accurate the A/F ratio on the Apexi turbo timer? what's a wideband? doesn't matter if I'm pushing my car hard or not it alway say 14.7 and maybe sometime it dip to 13.9 but that's it.

[SlamMan]

It's not accurate at all. A wideband AF meter uses a wide band sensor and is really the only accurate way to meter your air fuel ratio.

[AFAsucks]

sorry to butt in but i had a question about widebeand sensors. say you get the wide band O2...do you also need a different gauge to read accurately, or could you keep just a regular auto meter gauge and be able to trust it now that its being sent an accurate signal from the wideband O2 sensor?

[Talus]

If I remember right, if it uses your oxygen sensor, it can only detect an excess of oxygen and cant measure the full range.

[doctorstupid]

sorry to butt in but i had a question about widebeand sensors. say you get the wide band O2...do you also need a different gauge to read accurately, or could you keep just a regular auto meter gauge and be able to trust it now that its being sent an accurate signal from the wideband O2 sensor?
No. The two types of sensors are polar opposites in terms of signal voltage. A narrowband outputs lower voltages as the ratio gets leaner, a wideband outputs higher voltage as the ratio gets leaner. Beyond that, with a narrow band the correlation between air:fuel ratio and output voltage is non-linear, unlike a wideband. Not to mention the wideband is a 0-5V signal, narrow band is 0-1V.

Everyone who has a stupid little light show on their A-pillar needs to just throw it away already. A narrowband sensor can only accurately detect a stoichiometric air:fuel ratio, outside of that minute range it's just a rich/lean switch. A wideband reports air:fuel ratio as per this formula: voltage x 2 + 9. A narrow band is mostly a rich/lean switch, it's actual output voltages are 90% jibberish.

[WRX Harvey]

To clarify further. The Guage you have cannot be hooked to a wideband sensor. You will need a complete wideband sensor and guage kit. The LM-1 is affordable. I beleive Super-Rupair in boulder sells them for a good price.

[doctorstupid]

In hindsight, my answer was a bit over complex, wasn't it? :D

[STIBungy]

PLX sells a device that converts a wideband signal to the narrow which can be read by the A-pillar lightshow gauge like the autometer ones.

I'm waiting for my plx m-300 to come in.

[doctorstupid]

If you were to insist on sticking with a narrowband monitor, go for this one:
http://www.nordskogperformance.net/products/auto/proanalog/detail/d7014.htm

I remember seeing that converter for the Autometer gauges a while back. I still hate the light show, though. I talked with Nordskog and they are in fact working on a wideband version of that gauge. Sexified :D

[honda1982]

It's not accurate at all. A wideband AF meter uses a wide band sensor and is really the only accurate way to meter your air fuel ratio.

So it not really accurate right? because now the apexi turbo timer A/F is showing me 16.5-20.0 up and down and when I full throttle it stay at 20.0. Some of my friend tell me not to worry about it because it not accurate at all and that only a wideband would tell me if it rich or lean. Most dyno place have a wideband sensor right?