mort2002

iTrader: (1)

ok i just got my wide band installed this weekend along with my EGT guage and i was wondering what AFR i should be shooting for. i have a safc II and stock injectors and stock turbo.. my afr is all over the place i see everything from 10.4 to 12.2 i jut need some number to shoot for oh yea my egts are about 1475 and the egt probe is right next to the stock O2 sensor. any advice would help.. thanks
Rob

J-Rat

iTrader: (2)

Well, this is a source of some speculation.. My tuner generally runs my car at around 11.0-11.3. This is considered by many to be in the "safe" zone, but then again, it depends on your mods, boost levels, etc.

Since you are stock, I would think that if you could level the curve in the mid to high 11s (11.5-11.8) that would net you some power, as well as keeping things relatively safe. If you start pushing more boost, I would recommend dropping your AFRs a bit.

Rat

mort2002

iTrader: (1)

right now im only boosting to spikes of 10 to 11 and by redline im at 7 or 6 so im not getign that much boost.. i was just gettting a lot of mixed answers from friends some told me high 10s some told me high 11s so i look upon the rx7club people who actually know.

J-Rat

iTrader: (2)

High 10s is NOT necessary. If you are running 10 pounds on that stock turbo, then just tune for low-mid 11s. The extra fuel will help defray the penalty you are incurring by overheating the intake air.

mort2002

iTrader: (1)

see im getting th elow 10s when the boost is dropping off at 6k an d above.. i guess ill lean it out a little more in the top end.. god i need to get my bnr and injectors!!! any more advice on tuning in greatly appreciated

J-Rat

iTrader: (2)

Well, just remember this:

You are on a stock turbo, and ECU. Once you start "tuning" it with the SAFC, you have to remember that there isnt much retard in the mapping, and that can be a factor.

I am not too sure what the correlation between the AFM position and the pressure sensor do for fueling and timing, but from what i have read, it isnt a whole lot. I think NZconvertible is more up on this aspect. Reason I dont know is because I run a standalone of course..

Rat

mort2002

iTrader: (1)

yea i wish i could get stand alone but it is out of reach at this point .. and im so sick of that stock POS turbo!!

rx7legend

my afr is at 11.2 tuned with a safcII. the booost goes to 11 psi but when it reaches 6500rpms it drops to stupid numbers like 7, its really a crap stock turbo lol. but i gained desent hp, 220whp its not bad with the simple mods i have done.

gsracer

I recall henrik (the creator of the rtek applications) saying that 10 degrees of negative adjustment via the safc would roughly result in 1 degree of timing advance. If you're really worried about it just retard the CAS a couple of degrees. The stock ecu runs rather conservative ignition values as it is however.

mort2002

iTrader: (1)

when i talked to bryan at BNR he told me to pull 2 degrees of timing when i go to run 15lbs of boost.. i just dont want to blow up the motor kinda expensive to fix

RotaryEvolution

iTrader: (30)

safe #s are dependent solely on how accurate the wideband is and where it is positioned. too far downstream and the numbers will be skewed, too far upstream and the sensor will not be able to take the heat for long. most tuners use the wideband in correlation with a dyno to be sure the engine isn't starving but they also have a relationship with their widebands and know their sweet spot so to say. for the most part 11.0:1 is a good number to shoot for, it isn't pig rich nor excessively lean even if your wideband is a full point off it likely won't be enough to detonate and kill the motor.

J-Rat

iTrader: (2)

I am mildly disturbed by this concept..

RotaryEvolution

iTrader: (30)

i like to rub my wideband's sweet spot, she lets me know how she likes it...

bigdv519

iTrader: (3)

You and I both. One would think to eliminate as many possible variables in tuning, to net consistant results.

Kind of like me saying "I know my injectors, I have a connection with them. They might not be new, and exactly correct, but I know them."

Sounds like giberish.

RotaryEvolution

iTrader: (30)

hmm, that is a little different. we are talking about a single wideband not one you would rent with a dyno. why do you think most reputable tuners bring their own equipment?

mort2002

iTrader: (1)

well than what is the right place to put the sensor??? i put mine about 23 inches down.. where the downpipe wanst gold .. it was silver again (stainless)... i have the AFX if that helps too. i was told it was pretty good?? any ideas if it is?

mort2002

iTrader: (1)

BTW if wide bands are of by 1 point.. than why are they such a common tuning tool if they are always off or never right??

RotaryEvolution

iTrader: (30)

the stock O2 sensor location is a good point to look at but tuning cars that still have piggyback or stock ECU makes it a little difficult since it still utilizes the O2 sensor.

mort2002

iTrader: (1)

is there a way i can make the stock ecu read from my afx wideband.. woudnt that be better than? its a heated o2 unlike the stock?? i leave my wideband in all the time cuase i hardly drive the car.

bigdv519

iTrader: (3)

I would suppose they bring there own wideband because they don't trust any other wideband. Not that the others are bad, but they can net consistant results with their own. I would also suppose that any reputable tuner would calibrate their equipment as needed.

The stock O2 sensor has an effect on WOT???

RotaryEvolution

iTrader: (30)

thats kinda the point i was aiming at...

no the O2 doesn't affect WOT, any decent tuner tunes for mileage as well and that can't be done if the O2 sensor is fighting with a off the wall SAFC map.

mort2002

iTrader: (1)

the stock O2 has no effect at WOT. but if you mounted a widebad O2 sensor up that high it woudlnt handle the heat. my manual says that the wideband sensor shound to be above 1600 or it will cook the sensor that is why i put id down so low. it said to mount it 10 to 48 inches down in the DP.

RotaryEvolution

iTrader: (30)

some sensors can't take the heat for extended periods of time, if you plan on leaving the sensor in there for an extended period of time i suggest 1.5' downstream of the stock O2 sensor and keep the sensor mounted at least horizontally, preferably more upright to keep moisture from condensing in the sensor while it warms up.

just a tidbit of info though for reference, i have had my bosch wideband mounted in the stock O2 sensor location for about 8-9 months now and it still works perfectly fine with daily abuse. the stock O2 location is fine for temporary tuning purposes, many tuners use it while they do their tuning.

mort2002

iTrader: (1)

i did not know that.. at least i can say i learn something new on here every day.. i mounted it 23 inches down and almost strait up and down.. do you think it would be a good idea to get the wideband wired into the stock ecu for better reads?? it has 2 analog outs .. would one of those work for that application?

buttsjim

I just installed a new wideband, and ran my 0 - 1 volt analog output straight to the 2D pin on the ECU. According to the wiring diagram for an 87TII, there's nothing else in the circuit.

It seems to work just fine.