I was told today not to install my AFC in my DET 200sx. They said I wont need it and not to use it because it could leed to me blowing my motor. True or False:confused:

Well, I'm assuming you either have the stock det ecu or a JWT one, so why would you need a AFC? Even then, yeah, you can get the AFC to make a car run, but it's far from the best way.

Khiem

Do a search lots of talk about the AFC. U don't need one if u use a "JWT" ecu. There are alot of choices out there now. Emange.AFC,HK$ AFR or the "JWT" ecu. U sound like the kinda person who should just get a JWT.

Cough, cough bullshit. Quit hatten (sp) on the SAFC just becasue your probably affraid of it and because you probably have a JWT ECU and thats all good.

I don't want to start anything here but if you are going turbo you should be very mechanical inclined and knowledgable by this point and understand at a minimun the following: Just like Yellow4G63 said "U sound like the kinda person who should just get a JWT ECU"

1) Cloosed loop and Open loop*** If you understood this you wouldn't be asking questions. You would have said damn thank god for Fuel Controllers specifically Apex SAFC.
2) Brake Specific Fuel Consumption
3) A/F ratio and O2 sensor voltages
4) Injector Duty Cycle
5) BOV
6) Wastegate and Actuator
7) Fuel Pump Rated Flow
8) Base Fuel Pressure
9) And a few other important formulas and things.......the guys that tune there own shit know what I'm talking about, honestly though it really isn't that hard once your armed with the knowledge and know how.

Once you understand the facts you'll say "I really never needed an aftermarket ECU in the first place the stock one if just fine."But unless you do your homework you'll never know and quit listening to the majority because there just gonna tell ya go JWT because they don't know what us people know that tune our own cars.

I agree 100% with you.. Although I run a JWT ECU... I believe that there are other ways to tune our turbo cars now.. and they all have their good and bad points. The main reason I went with JWT is because of the redline issue. Other than that.. I would have used an Emanage.
Travis

ok withouth reading the rest of the posts, what is wrong with a afc?? and I don't get why people assume you can't use a afc with jw ecu's, it may be more money but if you want to get every ounce of power the afc can help.. the jwt ecu is tuning for a wide variety of things so it is going to be somewhat on the safe side, they can't grab every possible once out of the engine because with so many different possibilities some people shit would blow up, now if you have a jwt ecu as a base and then use an afc and actually know how to tune with one then you can gain every possible once of power your injectors can output and maf and so forth... But an afc can only compensate for so much so if you are going to be running with very large injector and maf than an afc might not be able to compensate for your ecu.. if your ecu is giving you the output for stock injectors and you compensate by using an afc but you are running 50 lb injectors than even an afc will not be able to compensate enough where you are running the 50 lb injectors to where you should be or compensate enough from running a huge maf than a stock one... I don't know if you get the idea I know I didn't do the best job explaining it but It's late and I'm trying to simplify it....
Sean

Im already making about 450whp with the JWT ecu, with the 720inj. I know how to use the AFC very well and I figured I could get the car to run a little more consistant. I just wanted to make sure it would work with the JWT ecu, but it sounds like I dont really need it

If it's running pig rich at WOT then u can use it. If it's running good u don't need it.

I have 370cc injectors and when I full throttle the car it goes completey rich.. I have the JWT and I also have a AFC (just have to hook the mass air wire up:) ).. So I think I finally got my answer keep the AFC and use it to tune the car to its most..

WOT, sure, you can make more power by leaning it out a bit. Depends on how much safetly margin you want. Aight, so what about part throttle? And from what I can tell the AFC only adjusts the a/f mixture by adjusting the amount of fuel injected at certain points relative to MAF readings.

Now, I think you'll agree with me that you need to adjust the timing advance to optimize power. Get something else to do that and then that'd be a good combo. HKS makes something doesn't it? All IMO of course!

You can get a car to run damn fast using these things. There are a couple 850whp Supras in Austin using them.

Khiem

Apexi use to make a ITC that u can set the igntion advacnce or retard with. The AFC also dose part throttle not just wot. If u really want it to run smooth u hook up a MAP sensor to the AFC.

Originally posted by spdracerUT
WOT, sure, you can make more power by leaning it out a bit. Depends on how much safetly margin you want. Aight, so what about part throttle? And from what I can tell the AFC only adjusts the a/f mixture by adjusting the amount of fuel injected at certain points relative to MAF readings.

Now, I think you'll agree with me that you need to adjust the timing advance to optimize power. Get something else to do that and then that'd be a good combo. HKS makes something doesn't it? All IMO of course!

You can get a car to run damn fast using these things. There are a couple 850whp Supras in Austin using them.

Khiem

[QUOTE]
Joes97turboSE-R I have 370cc injectors and when I full throttle the car it goes completey rich.. I have the JWT and I also have a AFC (just have to hook the mass air wire up ).. So I think I finally got my answer keep the AFC and use it to tune the car to its most..[QUOTE]

See above ^ this is the kind of answer.........from a person that doesn't fully understand A/F ratios or O2 sensor voltage. But don't worry there are people here that can help you.

1) First when you tell someone you are running RICH that isn't good enough because RICH just isn't RICH at WOT open loop.

a) RICH can blow your engine up and this is kind of stupid because we all run and some of us blow are engines up on the RICH side of STOICH I have never new anyone to run on the other side of STOICH at WOT for a period of time without blowing up.
b) You need to look at the A/F ratio table as 3 parts.
c) RICH 10.0*RRRRRRRR*STOICH 14:7.1*LLLLLLLLLLLL*LEAN 20.0

2) At WOT we are all on the RICH side of STOICH (I hope because if your not your engine will die in a heartneat).

3) We need not to say were running RICH but rather how LEAN are you running RICH. (Follow me) i.e between 10.0 to 14:7.1

4) That is why you need to tune by O2 sensor voltage and not A/F ratio light bar guages.


How many of you with light bar guages actually pay attention to how many bars it is away from the end @ WOT open loop and for that matter know what the corresponding light bar is equivelant to in O2 sensor voltage? My guess is you don't because if you did you would have something that reads O2 sensor voltage which is way more acurate because I don't know any light bar guages that read in parts very clearly.

Okay, but I have the A/F gauge hooked up to the O2 sensor.. So how do I tune it from there.. Thats where I dont understand the AFC part of this..

spdracerUT WOT, sure, you can make more power by leaning it out a bit. Depends on how much safetly margin you want.[QUOTE]

^****True****^

[QUOTE]Aight, so what about part throttle?[QUOTE]

^****Let the stock ECU control the closed loop/part throttle fuel mixture*^ It does a good job at it.****^

[QUOTE]And from what I can tell the AFC only adjusts the a/f mixture by adjusting the amount of fuel injected at certain points relative to MAF readings.[QUOTE]

^****A better way to put it........ the SAFCs sole job is to alter the MAF reading i.e. to tell the ECU it is seeing more air than it really is, up to 50% more air resulting in a RICHER mixture or vise versa telling the ECU it is seeing less air, up to 50% les air resulting in a LEANER mixture.

MORE AIR=MORE FUEL
LESS AIR =LESS FUEL
UP TO 50%+/- also it adjust in 1,000 RPM or 500 RPM increments and automatically smoothing the curve in between ****^

[QUOTE]Now, I think you'll agree with me that you need to adjust the timing advance to optimize power. Get something else to do that and then that'd be a good combo. HKS makes something doesn't it? All IMO of course![QUOTE]

^****When you alter the air/fuel mixture timing also adjust accordingly, it just doesn't stay the same****^

[QUOTE]You can get a car to run damn fast using these things. There are a couple 850whp Supras in Austin using them.

Khiem

^****No comment*****^

All in the name of better tunning at a more reasonable price.

Originally posted by Joes97turboSE-R
Okay, but I have the A/F gauge hooked up to the O2 sensor.. So how do I tune it from there.. Thats where I dont understand the AFC part of this..

FIRST OFF YOU STILL NEED TO DO YOUR HOME WORK BECAUSE YOUR ASKING A SIMPLE QUESTION AND I'M NOT GOING TO ANSWER IT FOR YOU BECAUSE IF YOU CAN'T ANSWER IT FOR YOURSELF STICK TO JWT..........BELIEVE ME ALL OF THE INFO YOU NEED TO KNOW IS NOW ON THIS FORUM RESEARCH >>> RESEARCH >>>>RESEARCH

First of this is why I say it and I'll say it again you need a A/F ratio guage that reads in volts unless you want to count light bars and that is still limited.

You should by yourself an Apex Turbo Timer for one you get the
Turbo Timer which you need
A/F ratio which you need
O2 sensor voltage which you need more than above
Battery warning nice thing to know
for $90 - $100

First off you don't really need to worry about tunning closed loop/part throttle cruising as the O2 sensor will adjust this automatically for you so the only thing you should be tunning in you drive way is your idle as this is open loop.

This is all the answer I'll give you ^ you need to learn everything, make it something you love and get down to the bottom of it, know what it is that I'm talking about instead of putting little bits and pieces together.

YOU CAN'T PASS THIS TEST BY REMEMBERIZATION YOU HALF TO KNOW YOUR SHIT.

I admit I'm not the best person on this board to explain things but I know what I'm talking about. I'm sure Mike K. could do a fantastic job at this and a few other people out there. But you know what this information that I'm trying to pass on is not that new its been around for a while.

Originally posted by Joes97turboSE-R
Okay, but I have the A/F gauge hooked up to the O2 sensor.. So how do I tune it from there.. Thats where I dont understand the AFC part of this..

easy as 1 2 3. Wath the O2 voltage and EGT gauge if u have one. The #'s will change as u add or take away fuel. If u keep adding more and the voltage keeps droping the EGT's are on the move towards melt down.

Originally posted by Yellow4g63
easy as 1 2 3. Wath the O2 voltage and EGT gauge if u have one. The #'s will change as u add or take away fuel. If u keep adding more and the voltage keeps droping the EGT's are on the move towards melt down.

Let me make this more clear although I know what you mean Yellow 4g63.

Yellow 4g63 that is a typo "If u keep adding more and the voltage keeps droping the EGT's are on the move towards melt down".

All though the above statement is true it is misleading becasue normally if you add fuel your EGT will drop. In the senario that Yellow 4g63 gave that would be true if an injector or two were malfunctioning or a leak in the fuel system has occured.


If you add more air flow as far as the SAFC is concerned that results in more fuel equaling a higher voltage reading i.e. .900mv roughly the area you want to be in at wide open throttle (open loop).

If you subtract air floe as far as the SAFC is concerned that will result in less fuel equaling a lower voltage reading i.e. .800mv roughly the area you don't want to be in at wide open throttle (open loop).

HIGHER VOLTAGE=MORE FUEL=MORE FUEL THAN AIR
LOWER VOLTAGE=LESS FUEL=MORE AIR THAN FUEL


The above isn't realy true because there is alway more part of air/oxygen to fuel but hopefully you understand what it is that I am trying to explain.

There is only one thing that I dont like about the Afc. It doesnt compensate for part-throttle/full boost situations. There is only a high and low map determined by throttle percentage. The high is usually tuned for Wot while the low is for whatever. There is also a crossover which meshes the high and low corrections. The crossover is not what you tuned for and is also where you might find yourself in part throttle/full boost situations. Such as when you downshift or when your on and off the gas taunting someone.
This mainly if you have large corrections or your crossovers are set far apart.

Originally posted by SucKit
There is only one thing that I dont like about the Afc. It doesnt compensate for part-throttle/full boost situations. There is only a high and low map determined by throttle percentage. The high is usually tuned for Wot while the low is for whatever. There is also a crossover which meshes the high and low corrections. The crossover is not what you tuned for and is also where you might find yourself in part throttle/full boost situations. Such as when you downshift or when your on and off the gas taunting someone.
This mainly if you have large corrections or your crossovers are set far apart.

2 question for you Suckit:
Do you drive a turbo charged car? Do you have an SAFC?

It does compensate for part-throttle/full boost situation.

High and Low maps come toghether in the MIDDLE.

The high is only tuned for WOT (open loop) for open loop is the only way the SAFC can be worth its weight in gold.

Low is not for whatever it is for idle which happens to be open loop thank god for this because if it wasn't you wouldn't be able to tune down bigger injectors.

The only other way low settings (closed loop) help is for instance...... the stock closed loop air/fuel timing map table can only compansate up to so much so say that you have really big injectors and the ECU can only muster up a closed loop A/F ratio of 14:0.1 Air/Fuel ratio then you go ahead and play with the low setting making all setting the same across the board and in this case you would want the ECU to see:

LESS AIR=LESS FUEL=THE ECU TO BE ABLE TO ADJUST FOR STOICH 14:7.1 IN CLOSED LOOP NON-WOT.


You can't be a part-throttle full boost.

By the way the ECU probably goes into open loop around 30-60% throttle this can easily be confirmed if you have and SAFC.......set the SAFC to show you THROTTLE % and watch your A/F guage or O2 voltage and when the A/F ratio or O2 voltage climes near 1 volt i.e 850mv-930mv you are now in open loop.

I wish there was a way to make the ECU run open loop all the time it sure would simplify everything and then switch it back to closed loop/open loop for smog purposes.

You need to no that the ECU only works in either closed loop or open loop no in-between loop modes:

CLOSED LOOP MODE= means that the ECU will compare the measured air/fuel ratio to the target air/fuel ratio (which is predetirmined from the factory for all vehicles and that is 14:7.1 for SMOG/CAT purposes mainly) and automatically increase or decrease fuel delivery accordingly.

(CLOSED LOOP WE DON'T HAVE THAT MUCH CONTROL OVER) And that is a good thing!!!!!! less tunning we have to do till an extent of our injector size SEE ABOVE POST


OPEN LOOP MODE= the ECU will still use the oxygen sensor to read air/fuel ratios, but will not adjust fuel delivery as in closed loop mode. This is a good thing!!!

(OPEN LOOP WE HAVE CONTROL OVER)