How well does an Safc II work in a N/A 7 with full intake and exhaust? Are the power gains worth it or is it just worth it to make the engine run that much smoother?

I searched the forum and didn't really get the answer I was looking for.

PS. Does anyone know how much to install it?

 

I had an intake and exhaust on my old N/A and it drove fine without an Safc. I can't imagine it being worth the money to install it when compared to the gain (if any).

For an SAFC-II I would imagine you're looking at about $300 just for the part and depending on where you get it installed.......maybe an hours worth of labour....roughly another $80.

So about $380 just to slightly smooth out your driving to a point that you may not even feel it. Not really worth the $$ IMO.

However, I've got almost $20k invested into an FC that I don't even drive so I probably shouldn't talk......=(

-Kenji

 

If you can tune, it's worth it. Both an increase in power and mileage will be the result. If you can't tune and don't have access to a wideband, then it's probably not a good idea.

 

lol You sound like an FD owner.


I've had an S-AFC (not II) in my 86 GXL for about 4 years now. We tuned it for fuel economy. The improvement was roughly 10%-20%. Mixed driving (mostly city) sees about 400-450km per 53 or so litres. All highway pushes that to about 550km. The most I've gotten out of her was about 630km on about 60 litres - I'd have to check the fuel log in the car to nail down the #s. I think it's reasonable to project that if I was to make a non-stop trip and kept her to 110-120km/h the whole time I could get 700km out of a full tank.

You're the first person I've heard suggest that it would make an engine 'run smoother.' How would altering your fuel/air ratio produce that (assuming that your throttle body and FI sys wasn't a mess?) The only device I've heard of doing that is a CDI box.

I installed the S-AFC myself. Took two tries. It was a pita to dig out the wiring harness, and it took some time to cut and solder everything, but it wasn't otherwise difficult.

I can't comment on power changes b/c I didn't care much about that and have no before/after #s to compare.

 

It should be more responsive so it should run smoother on the track anyway.

 

i had an safc2 in my 88 base na and all i used it for was to remove fuel at idle approxamatly 20% ... worked wonders took me 30 mins to install and i picked one up for 200 .. used they are cheep .. and if u can do things urself and play around a bit its fun and it looks cool to

 

I have an SAFCII and also a Wideband that i can datalog AFRs and other info with for tuning. I think it is a pretty good investment. I have picked up noticeable power AND fuel economy gains. i don't have numbers for power (probably not too much, just noticeable) but for fuel economy it worked out to 5mpg better on average. The stock ECU is known for running rich, however with some of the modifications such as header and full exhaust, blocking off EGR, etc. the car can run even richer.
with zero correction, i was sometimes seeing AFRs in the high 10s/low 11s at WOT! this was definetly not the best for power or fuel economy. i have since street tuned to 13 AFR at WOT across the range, and i can get my cruise as lean as 15.0-16.0 AFR. i average about 550km a tank, and under right conditions (highway only) i could probably do 700km a tank. i may have actually made up the cost of the SAFC in gas savings alone.

just a note though, with a wideband and datalogging you start to realize that the stock ECU is not the best in terms of adjustability range and also consistency. this could be due to that fact that the SAFC "tricks" the ECU into thinking it is at a different AFM reading. this is a direct relationship to how much fuel is needed, but you have no way to control what the ignition system is doing.
i think because of this i see the AFRs not always staying at the 13.0 that i tuned for. it's one of the reasons i want to switch over to MegaSquirt (which actually costs the same as an SAFCII).

 

S4 and S5 cars respond differently to mods.
S4 will run leaner with full mods
S5 will run richer with full mods.

Please tune accordingly.

I have a SAFC in my car. It's worth 5-7 WHP after proper tunning.
If you want to see some dyno graphs, search it under my name.

 

700km to a tank, i would be IMPRESSED! lol. My car nearly stock gets about 400-450 kms to the tank. or 18 or so mpg I estimate.
If I could find a used SAFC and install it myself, get it tuned for effieciency, i think it could pretty much pay for itself in a summer, I do way too much driving.

 

Check Parts for sale in the US. There's a guy trying to sell 2.