maxum17ft

iTrader: (7)

ok, so i've been getting bombarded lately with safc and wbo2 questions. i know there are other threads for the safc but i am dedicating THIS thread for the newbies to try to explain some simple stuff for them. mods if u feel this isnt necessary and want to make me keep recieving questions then plz be my guest and close this thread.

ok, i'll start it off with some explanation, if u have any questions or comments or more advice please post it up. now i know everything i said wasnt completely correct so if u feel im wrong in any way plz correct me.

here is what was asked today and here is my answer:
Quote:
Originally Posted by jeff
as i was reading in one of ur post about getting better MPG, what exactly is safc2 and the wideband senor u are talking about. Does thatt connect to the headers or to the cat converter. thanks for your time and any links to where u purchased these items would be greatly helpful..

jeff


safc2 is a piggyback fuel computer that alters your intake maf signal and in turn your computer will think its recieving different amounts of air, for example say with your stock computer it recieves a signal for your maf sensor in your intake that says 38khz at idle, so your factory ecu injects this certain amount of fuel "x" to keep the car at the stock air/fuel ratio which is 14.7:1 at idle and roughly 11.8:1 at full throttle.

air/fuel ratio means for example your engine takes in 14.7 parts of air to one part of gasoline and the spark plug fires and u get combustion which in turn allows power(hp)

with an safc u can change you air/fuel ratio at full throttle or basically anything above 15% throttle to whatever air/fuel ratio u want. with safc2 u can fake the maf signal by telling the computer its getting less air than it really is so it injects the amount of fuel it thinks it needs when really its getting say 38khz of air it "thinks" its only getting 30khz of air and injects the amount of fuel for 30khz which in turn puts more air in the comustion chamber.

u see, 11.8:1 air/fuel ratio is VERY rich and is injecting just too much gas into the motor which causes a loss in power and bad gas mileage. depending on your modifications u want a leaner air/fuel ratio, mine for example i have tuned to about 13.3:1 air/fuel ratio from 15% throttle all the way to 100% throttle. in other words i'm adding an additional 2 parts of air for every one part of gas over the factory settings, by doing this i am using 35% less gas and have about another 8 wheel hp.

now, the wideband is just a beefed up oxygen sensor and guage. all it does is tell you EXACTLY what your air/fuel ratio is. it detects the amount of unburnt gas and air in the exhaust and gives u the air/fuel ratio. u NEED this to tune any car, mainly because without it u wont know what your air/fuel ratio is, and if u go higher than a 13.9:1 air/fuel ratio on a stock engine, when u have more than 15% throttle, u will more than likely eventually blow the motor.


i spent many hours hooking up and tuning my safc and wideband o2 kit, and in return im getting between 40 and 45 mpg and another 8 wheel hp.

imho, the 700 dollars spent was WELL worth it.

u can get an safc2 from ebay brand new for 240 shipped and u can get any wideband(preferrably innovate or zeitronix) for about 380 dollars.



i hope this helps cause i spent like a half hour trying to explain it, but if it dont and u still want better mpg and more power just get rrm's piggyback, it should give u better gas mileage and definatly gives u more power.


pete

sadude

iTrader: (6)

Thanks for the info...the increased gas mileage alone might be reason to get this. Did you just tap the wires or were you able to use a already made harness?

Any pics of the install? Especially the interior part.

Wow...innovate motorsports has some nice new stuff. BTW which gauge did you get that matched with our stock stuff? you must have gotten the white face gauge with black trim rigth? where did you install??

It might be time for me to get an a-pod pillar and go nutz with the gauges

looking forward to pics

maxum17ft

iTrader: (7)

i tapped the ecu wires, but, u can get a harness if u want.

umm for pics of where i have the stuff, check out my cardomain @
http://www.cardomain.com/ride/2098976 i think i have some pics of the interior on there. IF u buy the innovate kit it comes with a white guage inlay, i just never got around to puttin it in. as it says in my sig, im done modifying for '05. i dont really have ANY time between, work, school, 2nd work, parties, and being lazy.

i might go take some pics of everything tomorrow though and explain how i tapped into the o2 wires in my cat .

sadude

iTrader: (6)

hold up...you tapped the stock O2 wires??? i though u said you got a innovate kit which comes with the LM-1 sensor...i am just reading your signature.

sadude

iTrader: (6)

does anybody make a single DIN install kit for the SAFC II...it just seems like it would fit in the lower DIN almost perfectly

thanks for the info

initialDRacer

iTrader: (9)

I currently have a turbo charger not installed (might install again soon). I might have to think about installing an SAFC and test it with the RRM kit. I was wondering though how much leaner I should go at 5psi...or 7psi

initialDRacer

iTrader: (9)

Oh yah, does the a/f ratio get affected on different climates. Say you've setup your a/f to work well with summer, which gave you 40mpg and +8whp. How will your setup change when you are now driving in the winter?

maxum17ft

iTrader: (7)

sadude, i wired my xd-1/lc-1 like this. i unplugged my o2 sensor in my second cat, then i screwed the wbo2 sensor in that location and wired it up to the factory o2 sensor wiring inside the car. the benefits are i have no holes for another o2 sensor in my exhaust and i didnt have to find another power source for the wbo2 sensor.

i believe carbontrix or somebody has a solid cf piece that goes in the lower din and u just cut out the cf for whatever u want, guages safc, ebc, etc.


DO NOT go leaner with turbo, turbo causes heat and u want more than enough fuel to help cool it down and not detonate with having such high compressons under boost.

idk how much my afr will change when colder temps arrive, i guess time will tell, i have a cai now but come winter i'll be going short ram intake to avoid snow packed on my air filter so my intake temps should stay about the same anyway. all i know is colder air is denser and denser air is supposed to yeild more hp so i guess we'll see come october.

initialDRacer

iTrader: (9)

Right, I guess that's understandable. I would like to know how the safc can be tuned in order to get the right amount of A/F without detonating the engine. Please don't tell me to go to a tuner, I don't have alot of money for that. I assume you would need to know the A/F but what needs to be tuned. The idling, full throttle, and also is it going to be different on which gear ratio you're on? How about at different boost?

Alchemist

iTrader: (23)

I did the math in another post about gasmilage. If you gained an average of 4 MPG (which will be a GOOD gain for a programmable piggy) it'll take you about 210 fill ups (if gas averages $3 per gallon) to break even on the hardware it'll take to safely tune a basic piggyback (if you're spending about $700). Check the "how to improve gasmileage" thread for more about why a piggy won't really improve MPG.

You can do this yourself but you have to be patient and careful. Wideband with datalogging is a must. The tendancy is that each higher gear gets a little leaner, which is why tuning in 4th gear is optimal.... but not a lot of us have the kind of open, copless raod needed to test the car up to 115MPH.

The ECU takes control during closed loop and will take care of things when it gets colder or hotter. As the weather cools down your AFRs will lean out a little (providing you have a CAI or some kind of duct to get non-engine bay air into the filter). You'll just have to keep an eye on it. I'd say you want to retune every couple months or every 20 degree change in average temp. Keep notes so you don't have to do all the retune work and you can just dial in.


Here's that thread: https://www.evolutionm.net/forums/sh...d.php?t=156892

And my MPG hasn't changed from 26 in ages, regardless of mods or driving style, except at the track. My AFR is about 12.8:1 because it's been shown that 12.7:1 AFR is optimal on these engines.

sadude

iTrader: (6)

it dawned on me after i posted that you probably just replaced one of the original ones...cool

i am honestly impressed by the astonishing huge gain in gas milage you got

rhyzin

iTrader: (1)

you must have one heavy foot. i check my mpg every month and i still get 34-38mpg from narrowband tuning. i don't think it would change much if i had a wideband, but you should have the mods to save you some gas. could be elevation though. i'm at sea level.

this could be a thread all on it's own. boe and others could probably be of more help in a thread like that. the basics would be to just tune for a certain AFR, like say 11.5AFR. if you get knock, add more fuel in that area. this is for WOT tuning and should be done LAST.

for idle and cruise, you'll need an obdII scanner and lots of fuel to go cruising. you basically check your Short Term Fuel Trims and Long Term Fuel Trims. this needs to be done SECOND.

Idle is the first thing you tune and is a compromise between your safc and the BISS screw on the throttlebody. you use STFT and LTFT here as well to tune idle. if you don't care for a lumpy idle, you can loosely just set your STFT/LTFT and go straight to cruise tuning.

more boost is going to need more fuel so there's going to be more adj in the rpm where there's more boost. say you tuned for 5psi of boost, then you raise it to 7. say 7psi of boost is made at 3500 rpm, then you'd probably only have to adj from 3k rpm up.

as Alchy said, the higher gear you're on, the leaner the AFR is going to be, so if you do a 3rd gear pull, run a a few points richer than your target. prob not much.

there are a few articles on the net on how to run headphones to the engine. you can just have a passenger just yell "knock" when he hears it but this is probably the best way. plx devices has a knock sensor with their wideband and there are other "knock boxes". i believe the safc2 V2 has a knock sensor.

Alchemist

iTrader: (23)

I'm at sea level, too. It's probably that all the driving we're able to do around here is stop-n-go because everyone is retarded and can't drive. Plus, in Seattle you're always going up a hill (I can take you on the tour of the GT4 track if you're ever in town ) Couple that with stickier than average competition tires (Azenis), that I do most of my driving to and from the track, that with the stage 2 cam it's really hard to shift at 3K RPM and still feel like you're making power plus my fat ***, and 26MPG starts looking good Gas Mileage around here is generally low. 24 is considered "good" by most of the folks I know.

sadude

iTrader: (6)

What is this narrowband tuning you speak of?

Is the best way via the SAFC II or should i jsut get a piggy back and see what happens...not sure how much adjusting I will do

initialDRacer

iTrader: (9)

I believe the safc 2 has a knock sensor monitor so your vehicle should have a knock sensor for this feature to work.

edit: as a second monitoring resort, having a EGT will help you determine if you have knocking due to engine temps getting past 900C. The ignition process happens so late that it will heat up the EGT probe. By that time, you should seize from boosting.