whats with the apexi afc??

[turbobluestreak]

I've been reading up on hks and apexi air fuel regulators that change the voltage being supplied to the ecu so you can run larger injectors has anyone ever tried this?? I know I can get on ebay and get an apexi afc for like 250 all the time and it looks cheap and easier to tune then a standalone.

 

tbs

[Tony240ZT]

People have tried to get them to work with the stock efi system on z cars, but have had issues. In particular not getting the correct RPM input, but I don't understand because our ignition system is pretty standard.

 

If you can adapt the system you MAY be able to get it to adapt a MAF to your car.. But this would take a LOT of trial and error, and a little bit of re-wiring, but only about 3 wires..

[turbobluestreak]

What do mean the DSM guys use it and I already have a Maf I am running the z31 ecu so no biggie and we both use a 6 wire maf. and we both use a cam or crank sensor to send ignition signal. so I think if they do it then so can the few of us with the z31 set up.

 

tbs

[Tony240ZT]

Sorry, didn't know how much you knew or didn't..

 

If I had the cash I'd give it a try. It does the same thing my little custom setup does. Wish I had my package ready for you guys, but it looks like I'm going to be doing some body work on the orange car for a little while instead of electronic stuff.

[Guest Zcarsmakemyheadhurt]

I use them every now and then on Subarus and Mitsubisi's mostly but the stock L6 TPS will not work on it. If your using a 300zx ECU and MAF with a voltage TPS I guess it could work. Check it out.

 

AC

[Dacelooper]

hey i have the Apexi Super-AFC and the z31 ECU swap but i cant find how to set the switches on the back of the Apexi controller... how do those who are running it have it set?

[majik16106]

use them all the time on supras, LOVE them.

[Afshin]

I just adapted the Z31 ecu/ams to my car and have also been looking into the different piggy back systems, but don't have any pratical experience with them as of yet and don't know how well they do with the AFM set ups since all the good stuff I heard about them related to cars with newer EFi and AMS.

From what I can gather the gredy e-manage is far superior to the HKS and apexi units and can be had for $250 new on ebay.

It would be nice to get feedback from anyone who actually used the e-manage on a Z or Zx

I had just posted this for someone else's question:

 

3 popular piggy back main air-fuel controllers are the Apexi S-AFC, the HKS S-AFR, and the greddy e-manage. They all can change the airflow signal from the MAF sensor, and hence adjust fuel delivery.

However the e-manage does much more, it allows for larger injector programing (you program a baseline larger injector with the laptop and then can fine tune the mixture at different rpm's manually on the dyno...)or AMS setting, adjustement of ignition timing, 3D mapping, datalogging and pretty much most of what a standalone does. Many of these functions will require a laptop, but since you are still using your original ECU and are not MAP based, it requires very little tunning and you maintain original functions such as AC, idle control , emisions....

Here is a site with some info:

 

http://www.boostsolutionsinc.net/technical-AFCcomp.htm

 

This was their conclusion:

Choose Greddy e-manage: If you do not care about using a laptop once in a while, and you want full air, fuel, and ignition control, with 3D maps, just like a standalone. With basic datalogging capabilities. Also great for you if you are planning on a bigger turbo and bigger injectors. Monitors the injector duty cycle as well.

 

Choose Apexi S-AFC: If you like playing with many displays, and like the big electronics screen, or want the show stuff for you car, the S-AFC is for you.

 

Choose HKS AFR: If you do not care that the HKS unit looks simple, and that you really will need the BOV correction function, along with the increased throttle response. Also, the HKS gives you more control over the curve. But you do not have the 2 maps, the knock display, and the other cool stuff from Apexi. The HKS is great for tuning though. The best price of all, as well.

[Bernardd]

You're not going to be able to mess with the maf voltage much. The z31 ecu will not allow a voltage below 2.2vdc or so. You can set it to read that at idle but as soon as you back out of the throttle and the voltage drops below range it will go into limp mode. You could bypass air and then retune the ignition timing, that would work.

[Afshin]

Thanks for the valuable info Bernadd. So according to your statement if I were to use larger injectors I would have to bypass some air around the AMS or modify it in a crafty manner such as SleeperZ did and only then could use one of the piggy back systems to fine tune it. I could not just use 370cc injectors and lean out the mixture with the piggy back system which would essentially lowers the voltage from the AMS to the ECU below the threshold for the Z31 unit and send it into limp mode

I wonder if we could get sleeper to modify more of these AMS, or even better, find out were he parks his car at night

Have you tried using larger injectors with an external air bypass ? Any idea or educated guess as to what size/diameter tube to use or initially try for a bypass to allow for 370 cc injectors ?

[Bernardd]

1/2 inch bypass tube should do it. I haven't done myself as I can get inside the rom and change the injector scalar, fuel and timing maps. I'm working on getting a z32 maf to work but may bypass air and retune as another option.