asherwood

I am thinking of buying an Apexi unit to clean up the quality of the burn!

Along the way hoping to increase milage, keep the plugs cleaner and possibly gain a little HP!

Please post your experiances with an air-fuel controller and it's benifits or any drawbacks when used on a N/A.

Besides it could come in handy if that much discussed FI Super Charger kit becomes a reality...

Thanks!

FDreaming

It's a great product, one of the best bang for the buck things you can strap on an NA. But, if your serious about the Forced induction thing go stand-alone.

asherwood

You mean like the Apexi Power FC? 'cause the application listing only shows '93-'95 RX-7's

Rotary Racer

II would assume he is talking about a Microtech, Haltech, SDS, etc.

I installed and tuned the S-AFCII on RarestRX's car. I have to say I agree that it is the best bang for the buck mod on his car to date.

- Dana

selanne8

i'm running an s-afc on my n/a. it's ported and i needed it to lean out the mixture when i have it smogged. it's hard for me to say what gains i got from it though since i replaced the motor (with a port job) and put in the s-afc at about the same time.

one nice thing about it is you can put your car in "fireball" mode to throw some nice flames :-D

j.ho

1990_whitecomet

where can i get or check out this unit.? and which is the most best.?

totallimmortal

I have an SAFC-II on my NA and I love it it really helped gas mileage once leaned out and richening the idle mix made my idle rock solid at 750, also looks cool mounted in the ashtray, most people just pull the tray and put it there i cut up the lid to make a trim around it, looks nice. Real reason for it tho is for when i get on a dyno to have it tuned then those number will be what i can base my judgment on

RarestRX

..

uRizen

iTrader: (2)

How much does one of those little puppies go for? And how bad are they to install?

RarestRX

Yo,

Before:



After:



It's the greatest thing since sliced bread. I bought my S-AFCII for $300 and spent $150 on the dyno tune. So for $450 I picked up almost 15 rwhp.

Changes the character of the car, I can almost call it "Fast" now!



Check out this thread:

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

And the original:

https://www.rx7club.com/showthread.p...hreadid=261173

Kevin
1989 GTUs "Really!"

uRizen

iTrader: (2)

Ok, I'm kinda new to the whole tuning aspect, but all you're actually doing is adjusting the fuel/air mixture at different RPM ranges to get the most power out of your car at that point, right?

Is this something that someone with soldering and electronic's experience can install, or is it scary?

I'd get one just because it looks so neat and I love random numbers flashing across cool displays. It makes me think of Star-Trek </geek>

RarestRX

Yo,

Yep, all you're doing is "dialing down" the injectors with the SAFC. You can go +/- 50%...you can see that I dialed my injectors way down. NA's are known to run very rich up top as an overzealous safety measure by Mazda. You can "lean out" your NA for my power. Most Turbo guys use the SAFC to control larger injectors.

If you can solder and have electronics experience, you'll do fine.

Here is a good write up from a fellow Forum member:

http://www.1300cc.com/howto/how2/safc.htm

Enjoy!

Kevin
1989 GTUs "Woo."

RarestRX

Yo,

Yep, all you're doing is "dialing down" the injectors with the SAFC. You can go +/- 50%...you can see that I dialed my injectors way down. NA's are known to run very rich up top as an overzealous safety measure by Mazda. You can "lean out" your NA for my power. Most Turbo guys use the SAFC to control larger injectors.

If you can solder and have electronics experience, you'll do fine.

Here is a good write up from a fellow Forum member:

http://www.1300cc.com/howto/how2/safc.htm

Enjoy!

Kevin
1989 GTUs "Woo."

introVert

Great info, Kevin-

And good write up. I was thinking about doing this at the behest of my local rotary mech. (Scott Glassburn @ Mazsport) and now I think I am gonna work some OT and dial this thing in.


TK

bingoboy

I doubt you will see any increase in milage unless you are clocking alot of road race hours. The majority of the leaning out is above 6000 rpm.

totallimmortal

I saw a huge increase in mileage about 4-5 MPG i call that huge for a single mod, of course thats while drivng like a little girl for the whole tank i got like 25 mpg, But if i get on it even once it seems to go down a bit, the SAFC lets you moniter throttle posistion too, and since in an s4 NA the ecu read 100% after about half throttle if you keep it below that it'll help alot, and it seems i usaually cruise ate about 90% which leads me to belive that i must have cruised at what the ecu thought was 100% alot before i got it

uRizen

iTrader: (2)

Increased MPG is what I'm really after with mine. It's a daily driver, so it doesnt' need to haul major ***. Is a dyno the only sane way to tune one of these? I've never been to one, and don't even know how they work, lol. Let alone how much the associated costs are.

asherwood

Wow, thats the spirit, a lot of good information! Thanks for posting the dyno sheets RarestRX.

I can see by the graphs that the power delivery is smoother through out the rpm band. One thing I did note that there was very little change in power below say 5500rpm. Almost all of the gains are made above that, significant gains, but only at the higher end. Also there was virtually no change in torque.

What I am also getting fom this information is that the best way to tune the S-AFC is on a dyno with a wide band O2 sensor? I saw the settings used by RarestRX, but have to think that they are pretty much specific to his engine and mods.

Would it be fair to say that the only way money spent on the S-AFC would be returned is by dyno tuning once installed? And that the butt dyno wouldn't likely feel much when the car is driven easy below 5500rpm?

Rotary Racer

double post

Rotary Racer

--

Rotary Racer

You are correct. This is the proper way to tune the car. The "butt" dyno is always wrong. Another way is to do true world testing with a wide band sensor installed in your car while your driving. Tools like the Innovative Wideband, or dyno jet's wideband commander would be a good start to look into for this situation. But for the price of those you could do a couple of dyno tune sessions. It all depends on your purpose, and budget.

I would also suggest having someone that knows engine dynamics, and has tuned a vehicle before with you while you are doing this. Knowledge is power.

- Dana

Rotary Racer

Triple post

Rotary Racer

forum funkyness

uRizen

iTrader: (2)

Thanks for the advice. I don't know a whole lot about the dyno tuning process at all. I like the idea though. If you go to a respectable dyno, will they usually have someone there that can help you tune it? Do you normally just run the engine at different RPMs then adjust the SAFC to get the best results at that point and continue up the powerband?

I'm assuming it's best to wait until you've done all your bolt on modifications before tuning as well.

asherwood

Thanks Dana, what about my comments about what the S-AFC actually accomplishes? i.e. "...only above 5500rpm" and " no significant change in torque"