FstFD3SPOWER

my friend with celica gain nice whp on dyno after SAFC..
do they work good on Fds?
My car is running rich right now and i want to make it run lil leaner...

what ya think?

FstFD3SPOWER

also during dyno.. how can i get Torque number?
last time this guy workin at dyno couldn't fig out where to hook up the wires..

ArchangelX

Obviously, I think you need to take your car to a DIFFERENT DYNO place. He obviously does't know what the hell he's doing..heh.

Anyways, Umm..I think the last thing you would want an RX-7 to do is run LEAN.

In fact..you'll get more HP with a bit more richness than without it...of course tuning is what makes the difference.

I had an S-AFC on my Celica (plan on using it with the RX7).

I was able to gain a 6hp gain throughout the power band..espescially during mid-lift, where I really needed it. Mind you this wasn't peak power, either...it was where it counts.

I'd think that using the S-AFC in the RX-7 would be more suited to using it for proper fuel management rather than trying to get HP gains...I think THAT is it's intended purpose.

Nice car by the way. Me likes...

skunks

mines works great

maxcooper

It is a lousy way to add more fuel on the FD, but it might help you take some out. If you use it to add fuel, you will hit fuel cut at a lower boost level. I don't see any problem with taking fuel out, but you will be reducing your safety margin. If you tune the car to run in the low to mid 11:1 ratios and you change the intake or exhaust system without re-tuning, you might pop the motor. So, just remember to richen things up before you change "flow" parts, and then retune after the install.

Be careful -- the RX-7 will be less tolerant of running lean than an NA Celica would be. Celica goes "ping - no matter", where the RX-7 goes "pop - no money".

-Max

FstFD3SPOWER

I live in SC... no other place

I know going lean is bad.... but last time when i dynoed car was running way to rich ( way off the chart) and sitll running way to rich... i want to lean it out lil bit.

sounds like safc will do the job.

sanfordman

I got 50 horspower out of my car with the s afc and a good tuner because I was running so rich, here is the thread with the dyno sheet, lowest runs were without the safc and the higher power runs were with it tuned. https://www.rx7club.com/forum/showth...hreadid=109874 .-B

ArchangelX

So what's the best way, then? Bigger injectors and Fuel pump?

What if you do all three.....

r0t0r-rooter

I had an hks dp, greddy pe cb, and k&n drop-in with my s-afc when I got dyno'd. With incorrect settings on the s-afc (~9.0 and below a/f ratio) I put out 234.9 hp and 229.4 lbs of tq. The boost stayed at 11 with a spike to 12 or so at transition. Since I've gotten the blitz filter and hi-flow cat i haven't been back to the dyno, but it should lean it out some.
I htink the s-afc is good for a beginner's car, but once you start playing with more power, there's no way it'll be up to the job. I originally only wanted a little more power, and keep the stock's reliability, but since meeting rotorheads like Max and Batmobile here in So. Cal, I don't wanna be known as "the slow MB". Unfortunately, Visa and AmEx have other ideas for my money (like paying them back)

maxcooper

Programmable engine management. The right size injectors to support your target power levels. And then a fuel pump that is adequate for the fuel flow and regulated pressures you will be running (a "more than adequate" fuel pump will not deliver any more fuel, but it is a good idea to have some safety margin).

My understanding is that the S-AFC adjusts the MAP sensor signal (so the ECU thinks you are running more or less boost than you actually are) to adjust the amount of fuel delivered. The problem with this approach is that the fuel cut is still present in the stock ECU, so if you need more fuel you will be closer to fuel cut. If you want to run more boost and need more fuel, you are extremely likely to run into the fuel cut, so the S-AFC doesn't work well in that situation. It might be a good companion for a "chipped" ECU that has had the fuel cut removed. That will give you some adjustability. But, at that point, you may have just gone ahead and switched to a PowerFC or something, which will be simpler to tune and costs about the same. Plus, you'll have one less electronic box.

-Max

ArchangelX

Sounds like I'll be selling my S-AFC...I'm getting a Power FC anyways..heh. :p

Dayam..it was one less thing to buy, since I ripped it off my Celica..heheh.

Oh well...I KNOW I can still use my Greddy A/F EGT sensor...

KevinK2

The s-afc allows one rpm based correction curve for below say 1/4 throttle (TPS), and another correction for above say 2/3 throttle, with linear interpolation between the two TPS set points. not bad.

As max said, best used for cutting back fuel. For higher than stock boost, used with upgraded ecu.

Best to dyno it in, as sanfordman did. I believe he had substantial power gains, but don't expect 300 hp at 8 psi on a dynojet with his mods. That number in his link is optimistic because of the dynapack dyno used:

1 - wheels are removed and measures torque to wheels, not torque delivered by tires. expect mabe 5% lower results with inertia dyno due to tire losses.

2- dynopack appears to have a software error, where calc'd hp is about 4 to 5% too high. I've noted this on other dynapack dyno plots. Hp is calculated based on measured torque and derived rpm.

HP=T x rpm / 5252

FstFD3SPOWER

well how hard was installing safc?? i hate wiring..
how can i read the rpm on dyno??

ArchangelX

My Celica was simple...should be the same for the RX-7...you just need the ECU diagram and make sure to solder it to the proper lines...

Batmobile

I had the SAFC and it didn't do much for me. I have a full exhaust, intake and FMIC. For some reason the car was running too rich at times. I tried leaning it out just a bit but to know prevail. I don't know if it was just me. I dynoed my car and it put 308rwhp with about 276 of torqe but my A/F ratio was about 13 to 12.8. In my experience I think the SAFC was a complete waste of money. I think it works well but not on our FDs. I should have save my money and purchase another ecu back then.