ANGEL1

I did a search for SAFC and it appears at least some of the members of this site have tried (so far it appears unsucessful) at installing a SAFC. I have a N/A RX7 and the reason why they work so well in the 7's is because the rotary engine in our vehicles runs very rich.

I question the gains such a system would have in our protege's, as our engines are probably already quite lean from the factory (in order to maximize fuel economy). Just curious as to the rational as leaning out the engine any further as it might not be the wisest idea.

MC

umm well according to the replies i got The protege Engines do run rich with factory settings...

also putting one in gives u better tuning capabilities.... (if i had the money i would go power FC but yeh haha)...

ANGEL1

Interesting. I can understand the fine tuning if the engine runs rich, but I just can't see there being a lot to play with out of a fuel efficient 1.6L engine. I am going to have to do some research about these factory settings... anyone want to take a guestimate on the potential power gains?

On the rx7s, the safc is used to lean out the engine ("and tune") after air-intake, manifold and exhaust have been upgraded...the power gain is quite decent, i.e. 10-15 horses. I can't see the protege experiencing that much of a gain (I am not hating, I love my protege).

Unfortunately, the vehicle doesn't appear designed to be tweaked, well, other than a turbo, lol

MC

well u caint put a SAFC onto a protege anyway... (i made a similar thread and Mr.Matty explained it in detail)... something about how @ full throttle the ECU goes to its maps to sort out the fuel issues and how it doesn;t take AFM readings @ full throttle...

so effectively making the SAFC useless @ full throttle... or something like that hehe

either way... i guess with any car... u put on a intake and full exhaust u WILL see a gain in power...

alot of cars come from the factory with restrictive intakes and exhausts well mainly to keep it nice and quiet and sometimes to keep emissions low...

like my friends Hyndai Excel... put on a full exhaust system (extractors, highflow cat, and catback with a good muffler) and a CAI... and put in SAFC... the gains were quite noticable... (comparatively to stock excel)...

goldstar

In closed loop, the A/F ratio is maintained at stoichiometeric (~14.7 to 1). In open loop, (i.e. at WOT and above a certain RPM), the A/F ratio is determined by pre-programmed fuel maps that for safety reasons sets the A/F ratio at a richer than best power mixture setting. It's here that leaning out would increase performance over stock.

zerocover

All I know is I gained some 20lb/st of torque down really low with an sri. Most likly becuase the ecu wasent getting a decent maf reading. Leaning the car out like all hell + the colder air which advanced the timing to the limit.

It caused the engine to knock/hessitate like all hell, and throw a running too lean code. Im thinking it was so tweaked that if that could have been brought up through the power band with proper tunning, I belive that at least 10-15 hp gain should be possible.
The 1.6 isn't that bad of a motor. IT has lots of power down very low and, it actually hits peak power way up at redline its just, by then, theres no torque.

IF anything a a/f controller would help keep the ecu from freeking out whenever mods are added. Would deffinetly help with the milage.

macdaddyslomo

once again a S-AFC will not help a 3rd gen protege except at partial throttle....The RX-7 works because of the OBD I ECU....

Zero I'd love to see a dyno showing a gain of 20 lb-ft of torque with just an SRI, leaning or not....

I'm tossing the brown flag.....

macdaddyslomo

It's SUPPOSED to be maintained at 14.7 to one....I've never seen a dyno yet on a 3rd gen that was actually stoich.....they are almost always rich.....

then again dyno's are usually at full throttle

zerocover

Whatever maybe not 20 13 actually, my memory was sketchy.
https://www.mazda3club.com/3rd-gen-engine-drivetrain-57/sri-%3D-nice-40635/

I really would like a a/f meter that would be nice to have. Gotta go out and get one now just to keep tabs on exactly whats happeing.

macdaddyslomo

So 13 with an SRI AND exhaust......

that's big difference from claiming 20 with an SRI

zerocover

I could always do the aftermarket manufactures thing where they take the biggest gains at an rpm not just at peak this case it would be down around 3000rpm around 16 possibly more ft/lbs. The stock # was with the exhaust. The new one is only a sri diffrence. Combined gains are probubly minimal.

regardless drag that gain across the entire powerband and youre looking at something very nice. Grab the jdm cams (like someone else we all know) that would bring up the power to a usable level. Then some actual tunning, power would be great.

Wasn't rod working on a SAFC for us that would get around the closed loop thing.

Ive been thinking about it and found an artical on autospeed, on a signal interceptor. All a AFC does is modify the MAF signal. So you run a AFC on the MAF then pick up a seperate signal interceptor and use it for the O2 sensor to make the car think everything alright. This would give full fuel control dont know what to do about the timing, maybe adjust the IAT.

macdaddyslomo

Sounds good, but the car still goes into open loop at full throttle...that's detected by the TPS not the MAF...

zerocover

The concept is open loop wont matter anymore. If you use a signal interceptor on the O2 sensor you could just have it tell the car its always running rich. Modify the signal so it reads 10:1 or something like that. The car will try to correct by leaning the a/f.

Then I would be a happy boy! And I would only have to dish out for one signal interceptor because woot is all that really matters for power anyway. I have to do more reading on how the O2 sensor does its job though. I ran my obd II reader and the O2 sensor reading was all over the dam place. Possibly wed need a switch to turn it on when the car goes woot.

LEADfoot

from what i've seen the choices
for fuel and spark fiddle'n are

power FC
e-manage
unichip-cork

AEM
Haltech

all of which(save the stand-alone AEM) alter the signals
coming out of the ecu
not goofing the sensors
going into the ecu

but i have stock management i don't know

ANGEL1

Thanks for the info. Don't think I would put a Haltech into a Protege or any car for that matter (unless it was turbo'd)...