2-N-D-pink

iTrader: (27)

i just got my neo installed and everything runs fine. now on the ETC setting there is an analog scale screen. rpm setting is adjustable on this screen from 6,000 rpm to 10,000 rpm. and correction setting is also adjustable here from
+6. +15. +30. and +50 percent.
is this setting where i set injector duty cylcle?
i mean under "air map" you can set your air fuel ratio. but on the analog scale screen the correction is on +6 percent. does this mean that the neo is giving me +6% duty cycle of 58 from the stock ecu?
also do set my rpm to 8000. what do you guys think.

SirCygnus

iTrader: (1)

you need to first understand how it alters the signal to the ecu.

it takes the readings from the AFM and alters it. it doesnt directly alter or know injector duty cycle unless it plugs into each indevidual injector.

now there are units that do alter injector duty cycle. but apexi isnt dumb enough to crap out good products.

2-N-D-pink

iTrader: (27)

so what exactly am i looking at here?

lets say i start changing the correction (analog scale), what am i really changing? if its not duty cycle what percentage am i changing? dont you get more gas out of your injectors by increasing duty cycle percentage?

all im doing to my ecu is lying to it. so explain to me the right way if im wrong.
whenever i tuned it, on cruise my air/fuel ratio is 14.3 wich it isnt bad for cruise. now whenever im under full throttle its set to 11.9 wich is pretty damn lean but im still running stock injectors, stock turbo with a tial 38mm .5 bar spring. im over boosting still, but i make it up with fuel.
the highest fuel setting (on air map) right now is +38 at 5500 rpms (because of over boost) and what your telling me here is that this 38 percent has nothing to do with injector duty cycle? and if it does...holy 96% duty cycle. i dont get it, maybe im stupid or someting.

arghx

iTrader: (3)

I had an SAFC 1, and I've used an SAFC 2, but never a Neo. But I'm sure they're the same thing essentially. The AFC Neo displays injector duty cycle I'm guessing (don't remember if an SAFC 2 could do that). Well that's just it, it's a display. Something that is duty cycle controlled uses a pulsed signal, not a linear 0-5v one like a normal sensor (AFM, IAT, etc). You can't just "trick" an ECU into directly increasing duty cycle/pulsewidth like you can with a linear 0-5v sensor such as the AFM.

When you add +38% you are adding voltage to the linear 0-5v signal that the ECU expects. So the ECU says "oh, I've got more air coming in. I should increase injector pulsewidths." Which in turn SHOULD increase duty cycle. But under a number of conditions such as light load cruising the ECU will practically ignore any "trick" signals the AFC is sending it. It just controls injector pulsewidth/duty cycle mostly based on the O2 sensor. That's why on the stock ECU you are not going to get it to consistently cruise at say 15.5:1 (which is doable on a standalone. I do it on my Power FC) if everything else is working right.

To summarize: in no way are you directly setting injector duty cycle/pulsewidth. You are just changing the linear signal from the AFM that the ECU expects, under the conditions that you set in the correction map. The AFM is only one thing (but a very important thing) that determines injector duty cycle and AFR. If you have this set to +38% up top and you still feel like you are lean, you are running out of injector or your fuel pressure is dropping due to a poorly flowing pump (like the stock one) or a poorly wired pump. So when the AFC tells you that airflow is 100% then that means the AFM voltage, before any correction, is maxed out around 5 volts. So you've maxed out the AFM already and the SAFC isn't too useful.

I'm pretty sure our cars have an AFM that increases voltage as the flapper opens (as opposed to decreasing voltage as the AFM opens, but essentially doing the same measuring process). So when you set correction to 20% I'm pretty sure it will take the starting % (let's say 2 volts, which is about 40% airflow, then add another volt to it. So the ECU sees more air coming in and adjusts fuel accordingly. That may not describe exactly how the AFC neo works, but illustrates how a piggyback functions by "tricking" the ECU.

2-N-D-pink

iTrader: (27)

good job, you just blew my mind up . i can see how it works but i really wish someone that has one will tell me where they have their analog scale settings.

i understand how the neo works perfectly now, but this analog scale screen with +6 +15 +30 and +50 setting messes with me. i mean, in this setting i cant go lets say +20% because its not an option. if i change the correction setting here......is this where im changing the linear signal that the ECU is expecting? or is it just under "air map" that this happends?





and by the way. i forgot to mention that im running a walboro 255. i dont think im that lean, but i just want that little bit of extra cushion.

arghx

iTrader: (3)

http://www.apexi-usa.com/pdfInstallation/42.pdf p. 18

I think you are getting confused by the monitor mode settings (analog scale etc). You need to just click on setting and play around with the correction map there. Also go into etc. and make sure everything is set up properly (sensor type, throttle, # of cylinders). Do you have an s4 or s5 car? I presume you hooked up the throttle wire exactly as the instructions call for?

And if you did not rewire your fuel pump it will still lean out.

2-N-D-pink

iTrader: (27)

no. what im tryna figure out is the diffrence between the two diffrent settings. i havent touched the analog scale setting at all. only the map setting under "setting" have been messed with. my sensors are reading right and # of cylinders are correct. hell, i even split the wires and sotter them just so i dont get any resistance by "butt" connecting them.

under sensor check:
(IG OFF) (IG ON)
IG------12.1 IG--------13.4

IN------3.843 IN--------2.458

IN2----00.76 IN2------.050

THR----0.0 THR------.911 (fluxuates)

OUT----3.828 OUT-----2.448

Lamp---0 Lamp---black 0

VT-------0 VT-------0

KAR----- -- KAR----- -- <not used

TCO----- -- TCO----- ^^


Under Air map (easy mode)
1000 2000 3000 4000 5000 6000 7000 8000
HI 0 +7 +10 +35 +38 +38 +36 +30= 11.9 AFR

LO 0 0 0 0 0 0 0 0 = 14.3 AFR

on the number of cylinders i have on 4.
the manual says if you got a rotary put it on rotary setting x2 but thats not there at all. so 4 cyl it is.

like i said there isnt anything wrong with the car. i just wanna know what the analog setting really does because i havent messed with it. if it doesnt do anything different (wich i doubt it) then ill go to pro mode and tune it again. but if it does make a difference then ill go head and make it work and see how it runs.
then ill right all the numbers down and wideband it some more.

1989 GXL
TII engine
stock turbo
stock intercooler
stock injectors
walboro 255
3 inch down pipe and exhaust
clutch net sprung 6 puck clutch
all emission properly removed and block off plates
apexi neo
tial 38mm on the stock turbo .5 bar spring
N370 ECU
one wheel wonder

fastest time is 13.9@ 104 mph with out neo and over boosting to 12psi with dry rotted tires(oops)

2-N-D-pink

iTrader: (27)

any one??

arghx

iTrader: (3)

The analog setting is a DISPLAY setting. It's just there to look pretty/cool/whatever. On the old SAFC's, when you were in monitor mode, you could press the arrow keys and it would switch between a graph, digital readout, and two cheesy looking analog displays (if you were in 2 channel monitor mode). Here you can set the scale of the analog looking gauges that can show up on the screen, that's all. AFC Neo manual page 16: "Analog can be selected from 1 channel or two channel [just like the old SAFC]. Indication items selected from each channel is displayed with the analog meters."

It doesn't actually do anything particularly important. Apex'i had to have some new features and an updated look. So they took the SAFC 2, added the crude vtec control of the VAFC, added the decel control (which is probably going to be useless and just make a backfire on our cars), and they added a color display.

When you say there is nothing wrong with the car, you have to realize that those are famous last words. If you are only getting 11.9:1 AFR with those settings, your injectors or your fuel pump aren't flowing enough. And it sounds like you are maxing out the stock 550's if you are sure you have enough fuel pump voltage. 12 psi is a lot for stock injectors, didn't you know that? +38% should be dumping in crazy amounts of fuel, not running on the verge of detonation, especially with the stock intercooler! You need to upgrade your injectors or turn down your boost. Look at my avatar. that is what you are driving right now... relatively lean mixtures + a heatsoak prone stock intercooler is dangerous.

SirCygnus

iTrader: (1)

just get some 720's and that will allow more play.

2-N-D-pink

iTrader: (27)

i do realize that 12 psi is a bit much on the stock injectors but this is the reason why i bought the neo (thinking i wasnt gonna pass the 80% duty cycle). the car used to over boost to 14 psi or more...once it starts to get that high i used to lift off. but on the stock turbo and 3 inch downpipe and exhaust there wasnt enough back pressure for the turbo. so i had to add some back pressure by welding some flat stock into my down pipe. now its down to 10 to 12 psi (depending wheather is a launch or from a roll on) so the highest map setting is +38% around 5k to 6k rpms then it drops back to 7psi. which still sucks because its more than 80% duty cycle.

i was thinking that this analog scale might do a diffrence but i guess is just a bunch of rice.

arghx

iTrader: (3)

well uhhh

^ I would be more worried about the intercooler being very inefficient at that point. Yes you are coming to the limits of the injectors but you have surpassed the efficiency of the intercooler. I beleive the stock intercooler is good for about 10 psi. lean+heatsoak=blown up. Just "food" for thought.

ok I just realized that someone already covered this...