Ok, at what point would you guys recommend getting an AFC? I hear a lot of people talking about how the N/As get really rich when you free up the exhaust and intake so I'm curious at what point most of you would suggest them. Also, can you really do anything useful with it without putting your car on an dyno for tuning?

 

The Safc works really well no matter what mods are on your car. Our cars run rich so putting in and tuning the safc will give your car a lot more power and better gas milage too.

 

True dat. I've read that the ECU dumps in an absurd amount of gas in the upper rev range. An S-AFC can correct that.

 

That's what I've been reading lately, and I'm very curious about the best way to tune it without a dyno, too expensive and not really too available around here.

 

Just go to a place with a wideband o2 sensor and then run the car on the street. Doing that should be better than doing it on a dyno because you get a more realistic amount of air for you car.

 

ok, another question I'm stupid someone explain the whole wideband o2 sensor that I've not read so much about.

EDIT: or I could just use the SEARCH BUTTON !?!?!?!

 

Hehe
go search...
=P

Its an accurate sensor to measure what air to fuel ratio you car is running at a certain point.

 

Great info guys, thanks for the help. Definitely gonna get one since I have plans for my car.

Hmmm... If I get about 28 mpg on long highways trips now...... nah, can't get much better than that.

 

I have an S-AFC in my car, but I'm holding off on tuning it until the 5th/6th ports are working (I have an rpm switch setup for them but the switch needs a repair.)

Anyway, I've talked to my mechanic at length about the S-AFC (he's got 10 years experience with rotaries, including drag cars) and he's assured me that a dyno isn't needed to tune it, nor a wideband. In his words, a couple of good, hard runs on a quiet road is all you need.

Make of that what you will. Me, I trust him, plus it sounds a hell of a lot better than $125 an hour to do the same job...

 

Uhhh I wouldn't trust him to tune your Safc without wideband...

Running too lean will cause detonation...

 

Well, good thing it's not up to you, then. He knows what he's doing and it won't be the first time he's done it. Don't worry - if the job does go south I won't send you the bill.

 

yea i'm gonna go tune my s-afc2 pretty sooon, my friend tuned his and he was able to sqeeeze out 24whp and is pretty lean...just on the edge but its all goood

 

do a baseline run, see ur afr and what rpms u get too rich under 12:1 then lean the areas out jus a couple points at first then do another run, a 125 hour is better than a rebuild or at the least time without ur car.

 

wtdpn: you saying he got an extra 24 Whp out of his car just by tuning with an s-afc2? What car is that on?

EDIT: Another thing, how much difference is there between running the apexi S-AFC and the apexi S-AFC II. Those seem to be the most popular ones. I know the II has more points and closer rpms, but is that the main difference? I would probably get the S-AFC, not the second one.

 

Ok..... Last time I checked we discussed that a SAFC is a waste for a first mod on a N/A car when there is so much HP to be made somewhere else(I.E. Intake , Exhaust , etc.). Also SAFC is used to control fuel to air ratio which I think is a waste to use on a N/A unless ported the only reason for a SAFC as first mod is to control your gas mileage and at thats a waste since you add on the exhaust and intake(which will suck more air in) your gonna eat more gas anyways since the SAFC is tuned for just stock. People use SAFC to just tune up the air to fuel ratio hence More fuel = More power.

 

People normally tune back their fuel. ie lean them out. Therefore "correct fuel to air ratio=power" not "more fuel=more power"

 

Psh... All I have to say waste of 300 dollars when you can buy a new exhaust or a CAI. But its your money.

 

but i have intake and an exhuast...without porting or swapping the engine...is the s-afc worth it? or wut mod is next?

 

You'll make more power with a properly tuned S-AFC then you would with a CAI or catback.

More fuel != more power
More air and fuel = more power

You use an S-AFC to LEAN OUT an NA.

 

Thanks Aaron, that's what I was thinking and since I consider you almost a rotary deity I will trust you on that it is worth it.

Gibenstein: What about the Apexi S-AFC (not II) that is on e-bay for less than or around $150? That sounds worth it for me. e: Even if just for gas milage and a few hp.

Also, concerning the exhaust/intake, I AM getting an exhaust, not the best but it will basically be a RB cat-replacement/presilencer to a *hopefully* Rx7.com 50mm cat-back, the cheap one Also, I'm thinking about getting some sort of intake and making an airbox, but I don't know if I have funds for that too. I need some for my girlfriend

And yes, I like the smileys

 

Rx7.com 50mm cat-back eh? check my sig.. is that the one you want?

IT IS? GIMME A PM !

BTW, i can get an SAFC for CHEAP. all this talk about more power gain is getting me excited. but i must save for the TII swap at the end of the year...

 

Yo,


Before:



After:



My true duals, Pineapple racing sleeves, ported manifolds, TB mod got me 5 extra RWHP.

The S-AFC II got me 15 extra RWHP.

You can decide which is the better mod.

Here's the dyno thread:

https://www.rx7club.com/showthread.p...hreadid=269541

It cost me $150 to dyno tune the car, which is considerably less than a new motor.

Kevin
1989 GTUs "Dyno time = worth it."

 

true dat playa. if i ever do get my SAFC i'll be tuning it on the dyno. i don't really feel like f*cking up my motor just yet...

 

s-afc is good for passing smog too (lean it out when the sniffer's hooked up)

john

 

well what do you think about tuning it with a wideband o2 sensor as suggested earlier?