ummm you may wana expan your question if you want some ppl to answer

 

More power means more gas. How does your ECU control things when you're running it beyond it's ability to operate?

 

Umm, no. You can run as rich or lean as you want. But to have your car run at its potential and safely, it needs to be tuned properly.

 

I'm sorry, I should have asked if do we need an S-AFC to adjust our cars to rich or lean.

 

Not exclusively. HKS makes the AFR.

Then there are Haltechs, Wolf 3D's, Microtechs, etc....

 

ok, so we need some sort of electronic device (either stand alone or tap in) for adjustment right?

 

Yes. The hack way of screwing with the AFM doesn't work too well.

 

ok thanks. So I guess it is worth getting a S-AFC to properly tune our car.

 

if you have an na and you say plan to get a pair of 550s you must have a lot of mods and a properly tuned piggyback (safc) or a standalone like the aem ems or haltek for your car to properly run no excuse me run at its full potential...or else it will run like **** and rich rich rich if you have a turbo then you can run a pair of 720s with a dp and full exhaust and you wont need an AFM If you just want to change your junk stock then just get an apexi safc...thats my choice

 

well, i think I am running rich. but check my mods and see if I need a S-AFC...

 

I'd get one and lean it out, on the dyno of course

 

Ya on NAs, people say you can gain 20hp from dyno tuning with an s-afc. Most I've seen is like 10-12 I think though.

 

The answer to that is NO. You do not need an S-AFC to lean out a rotary. You can ALSO lean it out by using an aftermarket fuel pressure regulator.

 

Eh?

Aftermarket fuel pressure regulators typically come in two flavors -

- adjustable base rate 1:1 ratio regulators for using an upgraded fuel pump that overwhelms the stock FPR and runs your fuel pressure too high

- rising rate FPR's that let you set a rising ratio of fuel pressure to boost to richen up your car under boost.

For a non-turbo application, there's really not an option for an FPR to lean the car out - it would lean out the whole powerband, where it really needs to be tuned at specific points. Not to mention if you drop the pressure too far, you'll have atomization problems having the line pressure too low for the manifold vacuum.

For turbo applications, both of the above devices apply. A rising rate FPR, in my opinion, is a bad idea. They're a royal pain to tune properly, and really don't offer that much adjustability - they're only good for a very moderate power gain.

On many occasions on a turbo, though, you need an adjustable FPR to set your base rate. A rewired Walbro pump will really jack up your fuel pressure - the extra flow overwhelms the stock FPR. Been there, done that.

The Super-AFC is a killer device for tuning in the fuel mixture - it's easy to use, it works great, it looks great, and it's reasonably priced.

Dale