I ordered and SAFC2 about 2 weeks ago.. and am waiting for it to get here. I read this on the Fc3s.org: http://www.fc3s.org/how_tos/electrical/afc.html . It says you need an A/f mixture guage or and exhaust gas temp guage to tune it correctly, or you can go on a dyno and tune it to your torq curve.. But I dont understand what all is involved in "tuning" it. Do you set how much fuel is used in each 200rpm incrament (spelling sux) or how does it work? Sorry for the stupid question, im just trying to understand it better..

 

With a wideband(wouldn't use an A/f) you check AFR's if you are too lean(danger of ping) you add fuel in that range if you are tooo rich you take a way a little fuel until you get to your personall goal for tunning. Although you should also get a baseline from other people with similar mods. YOu don't want to have a goal that is too lean and pop the rotors. EGT is a little bit different as it deals with heat in the exhaust. This is good because it also takes into account for timing changes and what not because that affects heat too. I am not too familiar with the ranges you shoot for normally for each but ask some of the more known members(REted, NZconvertible, Icemark, etc.) about what they recommend you tune for.

 

So I could just Get a wideband O2 sensor with datalogging, and go run my car, and then look at the data on the wideband and tune the Air flow control accordingly?

 

Yeah like say your wideband logs that your 10.00 AFR at 5k rpms you might want to drop it down to 11.00 afr by adjusting the AFC. Its that simple. The problem is knowing what is TOO lean and what is TOO rich.


Santaigo

PS- the AFRs were just arbitrary don't quote me on it.

 

So can different ratio's be too lean and too rich throughout the RPM range? If so, how the hell are you supposed to know what is too lean and too rich?
This is all interesting, I cant wait to play with it.

 

profile Says you have an 89 vert.... N/A???? What mods?????

 

Like I said talk to the more experience people on the forum. I don't want to give you what I personally think is a good afr and have your engine be damaged. N/a and TII tuning is also different. TIIs run richer than N/a's so much that if you would run an N/a tune on a TII you would probably blow the TII up.

 

BTW check your PM's Dezerte

 

Hey i have an '89 vert with an SAFC2. Though i have not had my car professionally tuned, i just adjusted the unit between runs. I don't have it pressed too far out of stock and it seems to do pretty good.

 

Well I currently only have intake, exhaust, streetport, TB mod, and Im about to port the intake manifold and remove the 6pi system, So I think a little bit of fuel management is in order.. Im also going to supercharge my 7, but Ive decided to do things a little bit differently so its going to be a little while before the supercharging is done. So im just going to tune for NA for the time being.

 

I had an 89 GTU with a RB cat elimination downpipe and presilencer (still had stock exhaust manifold) and R/B catback and a K&N filter with a cold air box... under full wide open throttle... my fuel was in the high 12's, which Dr dave at KDR said was kosher, until i hit about 5.5K rpm.. then it started a nose dive down to 10's by 7.5k rpm... (the lower the AF number the richer the fuel mix)

Now then... 10's are WAY to rich for an N/A... when I put the S-AFC on it, i took fuel out to keep it around 12.75 all the way up... and the car really woke up!!!

Rember to tune the SAFC at FWO... the car should use the o2 sensor to self adjust the fuel when you are not at FWO. when you go to FWO, the ECU switches to a RPM/MAF map and dumps fuel in wihtout using the O2 sensor for reference...

THEREFORE.. you want to make sure that your SAFC is set to remove fuel only under FWO......

Well... check that.. removing the 6-ports may screw that idea up...

Datalog the ENTIRE rpm band under FWO and see if you are running below 12

 

That would all make sense to me if i knew what FWO meant, Lol.

 

its in the post.... i think.. Full Wide Open. IE Peddle to the Metal... Hammer Down, Lead Footin it, Droppin the Hammer, Standin on it, Smashin the gas, pushin on the floorboards... etc

 

so, WOT
Thanks for all the excellent information

 

Not quite right. The ECU only goes into closed-loop (self-tuning using the O2 sensor) under low-load, steady-speed conditions. Most of the time it's internal fuel maps are being used. And WOT (wide open throttle) is a much more commonly used term. I've never actually heard anyone say FWO...

That'll make absolutely no difference at all.

Personally I think that unless you know what you're going (no offence Dezerte) you should take it to a dyno and have a professional tune it with a proper wide-band A/F meter. Quicker, easier and less risky.

 

Isn't a wide band in the $150+ range anyways?

Why not spend the $50 or $100 ish and get it on a dyno to tune with their wideband. They usually have one and will lend it to you to tune on the dyno.

Once I get my car broken in I will go buy a SAFC II and get it on the dyno. I want the AFRS to be set perfect. None of this cross my fingers and pray BS people do.

 

hmm, thx for the help. ill look into this more. I dont really know what Im doing exactly because ive never done this before. Couldnt I use my own wideband unit and tune it on the dyno myself? i didnt think they were that expensive..

 

The "Innovative Wideband O2" at rx7store.net is $349 without shipping. When you get your SAFC II tuned post or PM me on how it went and how long it took for it to get tuned, I plan on buying one later this month for my 89 vert and was also wondering about getting it tuned.

 

Your first comment answers your own question. If you don't know what you're doing and you've never done this before, then no, you should not do it yourself if you want good results and a running engine. Apart from the fact that dyno owners don't generally let complete strangers use their equipment (you pay them to do it), unless you know what you're doing the chance of a good tune is much lower and the chance of engine failure is much higher.