TheRedBox

Hey, Eric PM'd me to ask about the APEXi-SAFC. I thought that we could make this an open forum to where people with experience with it can help everyone out. So please if you have used it before, or have any questions please ask here.

Basically the SAFC is tapped into the ECU and it adjusts the AIR/FUEL ration being read. You can + or - fuel by percentages in intervals of serval hundred RPM (depending on which model you have). This is considered by many hardcore tuners to not be enough, (they all want standalones), but this is a VERY POWERFUL little computer, and without knowlegde of proper air/fuel, knock or timing you can destroy your engine in one pass. I highly doubt that we can do super serious damage to our little motors as of right now, considering there aren't many major mods out. Unless of course, you take the NO2 route....

Eric my suggestion would be to get a blinky A/F gauge, maybe a EGT. If they make (and if you can get your hands on) a datalogger that will be compatible with this car that'd would be better, as the AF and EGT gauges are not that accurate. I do know if you go with a venom nitrous system, some come with a nice fuel computer. I remember reading that the logger I had for my DSM is compatible will all OBD II care.. Let me double check on that...

eric_m

thank you for posting this. i appreciate it. i have my AFC all hooked up and everything works. i have a few questions and if any of you other guys have experience with the SAFC-II or the older SAFC, i can use all the info i can get.

as you might know the new SAFC-II taps into the factory knock sensor. this is the same sensor that the ECU uses to determine if it needs to add more fuel because you are running too lean. so it's kind of a safety device for knowing if you are pushing your car too hard without an A/F gauge. i do not know why they did not include an air/fuel reading on the SAFC as our car already has a pretty decent wideband air/fuel sensor that we can use to see if things are ok. it might not be as good as a motec sensor but it's better than nothing. i have a little guage made by split second that shows if the car is running lean or rich. it has about 10 LEDs and gives a pretty good indication. i had it on my wrx and the car was always running really rich when it was stock, so i think it's fairly accurate, at least for my purposes since i'm not going for all out performance.

anyway, my question is: how much knocking is acceptable? i get a little knock, even with 91 octane on factory settings. is this normal? i have redone the settings 3 times to make sure it was accurate. i just want to know what is acceptable so i can adjust the fuel for those throttle positions and RPM ranges where it's running a bit lean.

also, what do your maps look like? i was thinking of only having the AFC active in open loop mode, which means high throttle positions. so basically, under 90% throttle, the unit will not even do anything. i know that if i screw with the MAF sensor in closed loop mode, the ECU will adjust itself anyway and the car will not be any faster. the only way to trick the ECU is to make changes in open loop mode, lean it out as much as possible without detonating, and you will get the best results. i don't know if all cars are different, or if there is a common way the map should go, so i am looking for any advice you can give me. i've tried making little changes, but i have a lot more work to do to if it's going to be effective in making power. tuning on a dyno would be optimal, but i don't have the resources for that right now.

safety is my main concern, but i think i can get a little power from this engine without hurting it. should i add fuel at low rpms and remove fuel and high rpms? where do engines usually run richer?

thanks. sorry i'm such a noob at all this. i'm trying to learn as much as possible. i know it's not a very complicated piece of tuning equipment, but it is powerful, and people don't realize how much can be done by changing the voltage from the MAF sensor at the right time.

also, those "add 20hp" things you see on ebay are a variation, it is a resistor that goes inline with the sensor signal to change the voltage and lean out the fuel mixture. the problem is that in closed loop mode, the ECU sees this and compensates for the change, so you end up making no power at all, and in fact you might lose power. this is why i am going to only have the AFC active during open loop operation. i do not know at what throttle position it switches to open loop mode, but that info would be helpful to me.

TheRedBox

First here's a quote from a datalogging website..

"OBDII
The US government mandated that all cars manufactured for and after the 96 model year be OBDII compliant. Some manufactures picked up OBDII compliance as early as 94, but typically 95 or 96. If your car is 96 or later, it's OBDII compliant (but still may not work, keep reading). If its 94 or 95, OBDII compliant cars will say so on their under hood sticker.

Just because it's OBDII doesn't mean it will work.
But there is more to compliance. Ford and GM decided to use a different physical layer of the OBDII network. In other words, GM and Ford ECUs say the same thing (since it's OBDII compliant) but the means by which they say it is different. PocketLOGGER is NOT compatible with these cars. Some Toyotas also used this different interface as well as some Chrysler cars.

Known Compatibility
Cars not compatible with PocketLOGGER for OBDII include (but not limited to):
All GM and Ford cars. 1996-97 Toyota, all Toyota Supras (including 199, 1996 ISUZU, 1998+ Chrysler Intrepid, 300's, and Concord, 99 Subaru Impreza.

At this time we have no plans for a PocketLOGGER version that will work with the above cars.

Click here for *a partial* list of compatible cars and their datarates. If a car is not on the list that does NOT mean it won't work.

Cars outside the US are not required to be OBDII. It is up to the customer to find out whether or not their car is OBDII compliant.

More compatibility info
Honda's were not OBDII compliant until 96, except for the NSX which was compliant in 95.
Nissan's were not OBDII compliant until 96.
Mitsubishi Eclipse, Eagle Talon were OBDII compliant in 95.
3000GT and Stealth were not compliant until 96."

Now if that datalogger works with our cars AND you use in in conjunction with the SAFC you can become a tuning master!! hahahha well not really...

There should be a setting where you can set you throttle points. Llike you said for the 90% is only for your high setting. There should be a way to adjust that for your low and high settings. In the DSM world we used 35% low throttle and 85% high throttle, depending on how heavy your foot is. Generally, when the throttle is below 35% it wouldn't matter how much fuel going into the motor because the motor is not really working as hard. Also with the throttle open that little, the ecu will not use an excessive amount of fuel. The 35% low throttle settings are for your normal driving. Anything above 35% throttle is for you daily driving, and the 85% is basically the same as WOT. When you get into the 85%-WOT settings that's where you're going to want to be careful with you settings obviously, as that's where you bound to damage your car if you make a mistake. Don't play with the MAF, I have never thought it was a good idea, unless you are running rich/lean and you have know way to control your A/F.

I am too a newbie at tuning with NA motors. General rule of thumb is you will make the most power when you are bordering the fine line of running normal/just a little rich to blowing something up. I wouldn't worry to much about the ecu re compensating the the fuel trims, as I never had a problem with any of that.

*THIS WAS FOR MY DSM*
I had 550s injectors. The stock were 450s. Thats roughly a 15% difference. I would lean out the lower RPMs because the ECU doesn't know that the injectors are 15% bigger so driving around, I would be rich as ____. Now we boost kicked in, it would still stay in the negatives and slow reach 0 where it would be 15% richer than the normal stock mixture. Confusing I know.. I'm not too good with words.. But that should give you a good idea on what to do. I would try to lean the bottom end up JUST A LITTLE TINY TINY TINY BIT, just to see if it made a difference on WOT, if not dont change it. Hey even try to richen it up just to see what happends. Maybe you'll make more power. With the stock injectors you will want to add more fuel on the top when you start to spray.

Now here are some general tuning tips from the almighty RRE:

Initial AFC Tuning (Low)
While in neutral, try revving the engine to the exact RPM settings on the AFC. Hold the RPM, and then start playing with the setting for that RPM. Listen to the exhaust. Start on the rich side, the engine will likely sound very "smooth". Slowly work your way lean, you'll start to hear misfires (popping sounds). A good point is probably where things just start to pop a little but are pretty close to "smooth" (rich). Watch the O2 sensor voltage or A/F ratio meter. Normally the voltage will swing back and forth between .2 and .8 volts at idle and part throttle cruising. . As you adjust leaner, the ECU will compensate back richer. Slowly click down leaner so that the LEDs do not come up. You will then see the O2 voltage come back up slowly. This is the ECU re adjusting. Keep going down until the ECU can no longer bring the A/F ratio back up to swinging in the middle LEDs (.2-.8v). From there richen that rpm point back up about 10 percent. That should put you pretty close to 0 to 5% fuel trim at the ECU.

Next repeat the same thing driving the car on the freeway. Hold the car at the rpm that you are going to set. Note what percentage you are beginning with and slowly go lower until the ECU can no longer richen things back up. Go richer about 10% more and compare that with the compensation percentage that you started with. You should be fairly close.

When you get things too far out of whack, you will most likely get a check engine light code for Fuel Trim. It just means that the ECU was trying to adjust things to get back between 0.2 and 0.8 volts and couldn't. Don't panic, this is normal. Try to figure out where you were too lean or rich and fix it up. Re-set the ECU and see if the code re-appears.

Initial AFC Tuning (High)
The higher rpm ranges on the AFC are probably the easiest to tune (if you have an EGT). Use 3rd & 4th gear and go for long runs & watch your EGTs... If the temp gets over 900 Celsius in third gear, you are too lean. We've found that above 5,000 rpm, the settings are typically set very similar to each other.

The 2,000 to 3,000 rpm ranges are more tricky because you rarely stay in those RPM's for long & the EGT really won't help you. They'll likely be a little leaner than the higher rpm settings. The 4,000 and 5,000 RPM settings are the most important for maximum power and safety. Typically that is where you first punch the throttle when racing and also where the rpms fall back to when you shift.

Try to borrow a digital volt meter meter for your first major tests to prevent against grossly lean situations.

Ultimately it comes down to a lot of fiddling around over time. When cruising around, note the RPM's you are at and when you stomp on it, and pay attention to the next two thousand RPM's (it's important to concentrate on RPM ranges and not just overall acceleration...) You start to pick up on when the car is being held back by timing (lean) or if it's running fat. The exhaust sounds a little different (softer) & the power delivery feels different too.

Tuning With O2 Sensor Voltage
The stock O2 sensors are not very well matched between vehicles. They will give reasonably repeatable numbers run after run, but you can not compare your numbers with that of another O2 sensor. There are a few O2 sensors that have instrument grade accuracy but they run $800 and up. They also have a very short life span at that accuracy. Oxygen sensor voltage output will also vary with the temperature of the sensor. High end O2 sensors and their monitoring devices have complex circuitry to compensate for this.

The Blinky Light meters out there like Cyberdyne, Autometer, and EFI's Dual Meter are perfectly accurate at reading the voltage from the O2 sensor and lighting up the proper LED. The problem with them is when relying on them for full throttle tuning is that the range is not fine enough. There is a huge performance difference between .90v and .96v. Both of those voltages will light up the top most LED on these gauges. The LED based gauges do have their purpose in tuning closed loop/part throttle at a glance. For more accuracy, a digital volt meter is much better. For the best of both worlds, use the digital A/F Ratio meter from JumpTronix.

Bottom line is tuning with is fine with your own O2 and multi-meter but the numbers you are reading really have no relationship to anyone else's numbers to within .02v.

High EGTs and Knock
If you are running too lean for the boost and octane you have in the tank, you will get knock or pre-ignition. The knock sensor bolted to the engine block will pick up this "pinging" sound long before you can hear it inside the car. When under higher boost, there is almost always small amounts of knock. At these small amounts of knock the ECU will continue to advance timing normally. At mid knock levels the ECU will hold timing and if it gets too high or rises quickly, the ECU will begin to retard timing if not pull it all the way back to zero. You can hear the exhaust note change when the timing goes away. It will turn deeper , almost rumbly sounding. When the timing is retarded, the ignition process happens so late that the flame front shoots out the exhaust port when the exhaust valve opens and blows still expanding, really hot gas directly onto the EGT probe. So internally the pistons are barely warm, but the exhaust manifold and turbo get real hot. This is the reason we recommend not running EGTs higher than 900 degrees C. That is the point that timing retard is usually driving the EGTs up. Not that immediate damage is being done, it is just that you are no longer making additional power above that temperature and there is no benefit to running there.
Super AFC Tuning Tips
Purpose
The Air Flow Converter takes the pulse (frequency) from the Mass Air Flow meter and either speeds it up or slows it down at different RPM points to make the ECU run the injectors either richer or leaner. All by itself, it can only give you a little more bottom end power by leaning out the mix some. If you try to richen the top end you will just hit fuel cut (100% fuel inj. pulse) sooner.

One use is to cut out the restrictions in the lower half of the MAS (leaner) and then use the AFC to richen things back up. This gives some benefits similar to the VPC without the strange idle problems. If you have a 90-94 Eclipse, an excellent use is to convert to the MAS from a 95-99 Eclipse. The wiring connector is different but can be swapped to the 95-99 plug. The wires are the same. The calibration with the 2G mas is different but the AFC will allow you to compensate for it.

The biggest use for the AFC is to install larger injectors (richer) and then adjust the AFC leaner to compensate. This also raises the point where you hit fuel cut since the ECU sees less air flow (lower frequency Hz).

Installation is simple, and just requires tapping into 5 wires and cutting one to intercept the air flow signal. This is all done at the ECU. There are 8 RPM adjusting points to adjust the air flow + /- 50%. These points are user defined within a 1,000 RPM band so that you can get finer control in certain areas if you need it. The rpm points come pre set at every thousand rpm from 1,000 to 8,000. The graph is highlighted for the rpm range you are setting.

The new AFC also allows for two different maps according to load. It makes the load calculation based on the Throttle Position Sensor. You choose what is high and what is low. We normally set it for 30% low and 80% high.

Initial AFC Tuning (Low)
While in neutral, try revving the engine to the exact RPM settings on the AFC. Hold the RPM, and then start playing with the setting for that RPM. Listen to the exhaust. Start on the rich side, the engine will likely sound very "smooth". Slowly work your way lean, you'll start to hear misfires (popping sounds). A good point is probably where things just start to pop a little but are pretty close to "smooth" (rich). Watch the O2 sensor voltage or A/F ratio meter. Normally the voltage will swing back and forth between .2 and .8 volts at idle and part throttle cruising. . As you adjust leaner, the ECU will compensate back richer. Slowly click down leaner so that the LEDs do not come up. You will then see the O2 voltage come back up slowly. This is the ECU re adjusting. Keep going down until the ECU can no longer bring the A/F ratio back up to swinging in the middle LEDs (.2-.8v). From there richen that rpm point back up about 10 percent. That should put you pretty close to 0 to 5% fuel trim at the ECU.

Next repeat the same thing driving the car on the freeway. Hold the car at the rpm that you are going to set. Note what percentage you are beginning with and slowly go lower until the ECU can no longer richen things back up. Go richer about 10% more and compare that with the compensation percentage that you started with. You should be fairly close.

When you get things too far out of whack, you will most likely get a check engine light code for Fuel Trim. It just means that the ECU was trying to adjust things to get back between 0.2 and 0.8 volts and couldn't. Don't panic, this is normal. Try to figure out where you were too lean or rich and fix it up. Re-set the ECU and see if the code re-appears.

Initial AFC Tuning (High)
The higher rpm ranges on the AFC are probably the easiest to tune (if you have an EGT). Use 3rd & 4th gear and go for long runs & watch your EGTs... If the temp gets over 900 Celsius in third gear, you are too lean. We've found that above 5,000 rpm, the settings are typically set very similar to each other.

The 2,000 to 3,000 rpm ranges are more tricky because you rarely stay in those RPM's for long & the EGT really won't help you. They'll likely be a little leaner than the higher rpm settings. The 4,000 and 5,000 RPM settings are the most important for maximum power and safety. Typically that is where you first punch the throttle when racing and also where the rpms fall back to when you shift.

Try to borrow a digital volt meter meter for your first major tests to prevent against grossly lean situations.

Ultimately it comes down to a lot of fiddling around over time. When cruising around, note the RPM's you are at and when you stomp on it, and pay attention to the next two thousand RPM's (it's important to concentrate on RPM ranges and not just overall acceleration...) You start to pick up on when the car is being held back by timing (lean) or if it's running fat. The exhaust sounds a little different (softer) & the power delivery feels different too.

Tuning With O2 Sensor Voltage
The stock O2 sensors are not very well matched between vehicles. They will give reasonably repeatable numbers run after run, but you can not compare your numbers with that of another O2 sensor. There are a few O2 sensors that have instrument grade accuracy but they run $800 and up. They also have a very short life span at that accuracy. Oxygen sensor voltage output will also vary with the temperature of the sensor. High end O2 sensors and their monitoring devices have complex circuitry to compensate for this.

The Blinky Light meters out there like Cyberdyne, Autometer, and EFI's Dual Meter are perfectly accurate at reading the voltage from the O2 sensor and lighting up the proper LED. The problem with them is when relying on them for full throttle tuning is that the range is not fine enough. There is a huge performance difference between .90v and .96v. Both of those voltages will light up the top most LED on these gauges. The LED based gauges do have their purpose in tuning closed loop/part throttle at a glance. For more accuracy, a digital volt meter is much better. For the best of both worlds, use the digital A/F Ratio meter from JumpTronix.

Bottom line is tuning with is fine with your own O2 and multi-meter but the numbers you are reading really have no relationship to anyone else's numbers to within .02v.

High EGTs and Knock
If you are running too lean for the boost and octane you have in the tank, you will get knock or pre-ignition. The knock sensor bolted to the engine block will pick up this "pinging" sound long before you can hear it inside the car. When under higher boost, there is almost always small amounts of knock. At these small amounts of knock the ECU will continue to advance timing normally. At mid knock levels the ECU will hold timing and if it gets too high or rises quickly, the ECU will begin to retard timing if not pull it all the way back to zero. You can hear the exhaust note change when the timing goes away. It will turn deeper , almost rumbly sounding. When the timing is retarded, the ignition process happens so late that the flame front shoots out the exhaust port when the exhaust valve opens and blows still expanding, really hot gas directly onto the EGT probe. So internally the pistons are barely warm, but the exhaust manifold and turbo get real hot. This is the reason we recommend not running EGTs higher than 900 degrees C. That is the point that timing retard is usually driving the EGTs up. Not that immediate damage is being done, it is just that you are no longer making additional power above that temperature and there is no benefit to running there.

"I turned up my boost and the car does not feel any faster"
The power can drop off after a while when increasing the boost due to intercooler flow and intake temperature. The trick is to find the lowest boost that still feels strong. You might as well run just what boost you need to make power rather than stressing the turbo and chance detonation on pump gas. Now with race gas it is a different ball game and the max power point should increase so you will want to try turning up the boost another 2 PSI or more.

What kind of turbo and intercooler do you have? If you are using the stock stuff, then your boost is limited by the turbo. The most you will get out of it is about 15-16 PSI which is fine on pump gas. If you manage to somehow get more boost you are likely just making hot air and making less power than you would at a lower boost since you are pushing the turbo way past its efficient operating range.

If you have a 16G and a decent front mount intercooler in cold weather (50F) you can make around 300 HP properly tuned. If you have a larger more efficient turbo, such as a 20G you can make even more power on pump gas properly tuned.

Fuel Cut
It's a nice cool night out and your Eclipse was running better than ever. You were boosting a little higher than you normally do and BAM, the motor shuts off hard and there is a backfire. You ease back into the throttle thinking you just blew up something big. The car seems to run fine. Welcome to Fuel Cut.
You were just flowing more air through the MAS than the ECU was programmed to deal with.

There are several possible solutions to fuel cut. The dime store FCD works fairly well but is potentially dangerous and doesn't net consistent results. It doesn't really solve the problem but is a partial workaround. The next solution is to get the Fuel Cut removed from the ECU altogether via TechnoMotive. This definitely does the trick but still doesn't really solve the underlying problem of running lean. Ideally you should install larger injectors and a fuel computer of some kind, like the AFC.

Fuel cut is caused by the ECU seeing a large airflow value from the MAF which works out to roughly 100% duty cycle on the stock injectors. If you install 550cc injectors which are 18% bigger than the stock injectors, then adjust the AFC to compensate for the larger injectors, you won't hit fuel cut until you
make up that 18% airflow buffer. Ideally you should get the injectors, AFC and the Technomotive ECU mods. This gives you safe, consistent fuel and allows you to run ridiculous boost levels without running too low on fuel or hitting fuel cut.

Also an EGT is generally a good idea once you start running high boost levels or hitting fuel cut. The ECU thinks you are getting close to maxing out your fuel system, and the EGT can tell you for sure. It is an expensive item, but cheaper than an engine. Just get the GReddy electronic gauge and mount it in the #1 or #2 exhaust runner. You will also need it to tune the car properly with a fuel computer.

TheRedBox

Hope that helps.. Sorry for the long post.

TheRedBox

Oh and don't fuel cut can and will occur when the IDC (injector duty cycle) reaches or passes 100%.. You don't want your injectors running that much...and the only way to really know what your IDC is, is by using a logger.

eric_m

thanks for the info. larger injectors might be a good idea. i'll look into it.

i also think that with a fuel pressure regulator and the AFC, i might be able to run a turbocharger with 5-6psi boost if i make my own exhaust stuff. i would obviously need an egt gauge and i would have to monitor everything to make sure everything runs ok, but i can always richen things up to make sure it runs ok. wouldn't cost too much, either.

TheRedBox

Dont forget a fuel pump. Probably the best fuel mod you can ever do to you car......

eric_m

i used to have something called an HKS camp on my subaru. it could read injector duty cycle. basically, it's just a voltage output by the ECU. i tapped injector #3 and i could see how hard those things were being worked. you could probably easily use a meter to determine duty cycle by voltage.

TheRedBox

I really wouldn't do injectors unless you are doing F/I. As far as injectors go for nitrous I think that set up will work very well, but you would have to change settings from when you're on the bottle and not. Does the SAFC II come with different settings as in a "A or B" type of thing?

eric_m

yeah, safc has 2 settings you can switch between, which is cool. i'm not running nitrous anymore though. i had it all installed but i took it out before i even got to use it. i know this sounds weak, but i don't want to take any chances since i am not confident about the returnless fuel system and how it works.

TheRedBox

The knock sensor, to my knowledge, is just a mic near the motor..That should explain why you get knocking when you hit a bump, another possibility would be the wires are loose. Make sure the connections are very very tight. I recommend soldering and heat wrap. You don't want to fry your ecu..

Get the EGT and A/F, but I don't know what EGT to tune for for a NA motor. I can however do some research and find out. All motors are different. If you do get the EGT we can go off what temp you are reading and I can give you tips. I have a buddy selling a greddy EGT 60mm. Let me know..

Honestly with the blinky A/F gauge it's going to be really hard to determine if you your making power. You really want to make sure the timing is stay constant and keep advancing, you only want little counts of knock. For my dsm I tuned for 750 degrees on WOT. Higher the temp leaner the motor. You are not going to want to get to far away from zero either. I'll still waiting for a responce to know if the datalogger will work for our car.. HTH

Daniel

eric_m

thanks daniel. i know those A/F meters are hard to read because they are all over the place, and i know that i am not knocking at WOT anyway so my concern is with the exhaust temp. i want to get a 52mm greddy EGT gauge. i think 60 is a little big for the xB. greddy makes good gauges for the price, and it's electronic, not mechanical like most cheaper gauges. anyway, i think i can take some baseline EGT readings and then make sure i don't go much hotter. even if i'm knocking a little, if my exhaust isn't too hot i should be ok, right? i just get spikes of knocking, and it seems to happen more when the engine is warmer for some reason. i know it's just a mic on the engine, but right now it's the only thing i have to tell if my engine is ok or not, except for listening for detonation, but i have not heard anything of the sort at this point.

my question was also how to set up the map. should i richen it up at lower rpms and lean it out near redline, or is it the other way around? or maybe i just need to use a consistant change througout the powerband.

i heard that some guys are using these AFCs in their turbo civics and getting 20+whp with good tuning. that's impressive!

TheRedBox

When your in a NA motor, with factory stuff, your gains will be minimal. I want to say a couple of WHP if even that. F/I & nitrous cars have the potential to make gobs of power, they need that perfect AF ratio to make gobbs and gobbs of power. Turbo and Superchargers are like playing with a bigger bat . A all motor car can swing just as hard but it doesn;t have the potential to go as far. Since the Turbo cars bats are so big it hard to find the perfect spot to swing to make th ball go that much farther. As opposed to the smaller bat where the optimun settings are fairly close to each other. That's why cars with forced induction take so long to tune, but always yeild a better outcome. I'm really trying to stay away from giving you settings because I don't wanna be responsible if anything goes wrong. For the DSM, I richened up just a tad in higher RPM ranges where the engine would make more power. If you're getting knock trying to a add a little fuel in the RPM area that you get knock. (that's just typica.. I have heard of cases where EGTs were soaring high above 800-850 and adding fuel did not bring temps down, however, when then leaned the motor out temps when back down to the 725-750 range) If that doesn't work try using 91 octane and see if the knock goes away. If non of that works.. then.... :?:

ScionVan

eric: leaning your car will always give you more power... to a certain point. And then it goes BOOM! Adjusting a/f definitely does help more on turbocharged cars, but that's because most turbo cars are usually tuned (from the factory) to run extraordinarily conservative cuz the factory doesn't want you to blow up your fresh ride and take them to court. N/A cars, especially fuel efficient ones are usually actually tuned pretty well from the factory already, so gains seen with little piggy-back electronic boxes will probably be very minimal. But if you are trying to eke every bit of power that you can, and/or are trying to tune it to run with something like NOS or something, then something like the Super-AFC will definitely help some. Personally, I think that for a street car, you should tune it more conservative on the high end, just to be safe, and try and get the most power out of the midrange where you will be driving it the most anyway...

Alter_Ego

You really should get some dyno time with the safc if you think you have some good maps setup or you can work from a conservative start with it and lean it out as you get results from the dyno graphs. Money well spent.

You won't need a fuel pump, injectors, or a adjustable fuel regulator unless you are going forced induction.

jOaNgHoSt

A friend gave me one of theese APEXi SAFC but I have no clue on how these work or how to install it on my tc, I'm all stock but how does this computer helps my car ?? does anyone has a diagram on how to install it on a TC ?