a/f ratio in a non turbo?

[xzeror]

when i bought my 7mge it came with a a/f meter, does a/f ratio matter in a non turbo? i know it matters in turbo cars but whats the use in a non turbo?

 

[hvyman]

all cars have certain a/f ratio or else the engine will bog or blow. stock ecu on a n/a will control the a/f ratio fine and is pretty much useless on a n/a. basically its just there for looks.

 

[Poodles]

More than likely it's the "light show" narrowband gauge anyway

 

[gofastgeorge]

A/F is definately required in a performance NA,
but only if you have some way to adjust fuel delivery.

Under partial throttle, the ECU is in closed loop, and does pretty good.
But with mods, like a free flowing exhaust, or intake, it won't, because it goes open loop.
Free flowing exhaust will leave behind less exhaust gasses in the combustion chamber,
so the already lean fuel delivery (meant for ecconomy numbers, and the EPA) will be even leaner.

Under full throttle you should be at about 12.5:1 A/F ratio.
I use an Apex S-AFC, and an adjustable fuel pressure regulator to get there.

 

[xzeror]

More than likely it's the "light show" narrowband gauge anyway

yes its an autometer narrow band, everytime i drive its mostly in the lean side all the way to the bottom.

 

[jetjock]

^ Which is exactly why they're not as useless as many claim...

 

[gofastgeorge]

Yup, those cheap-as narrow bands are not worth the effort.
They are for the US pig-iron V8 guys with carburetors.

 

[Poodles]

^ Which is exactly why they're not as useless as many claim...

Depends, that's assuming it's correctly hooked up

 

[IJ.]

Depends, that's assuming it's correctly hooked up

It will however show when the narrowband02 has fallen over and explain the horrible fuel consumption

And you can get all anal and keep it in the green for economy runs!