I have searched this topic and haven't found an answer that I'm satisified with. I'm not big into technical information by any means, but I have some questions regarding SAFC in general.

1. What's the main difference between an SAFC and an aftermarket EMS such as AEM, Motec, etc.? I assume an aftermarket EMS can do everything an SAFC can do and more, so why bother purchasing an SAFC besides SAFC being cheaper?

2. When does the SAFC/EMS settings have to be changed? After each additional modfication to gain the most horsepower? I understand all the tuning has be done on a dyno to see the changes in horsepower.

 

It's odd that the VQ Maxima/Altima crowd has embraced the $300 SAFC and it consistently sees gains of 7-10whp/wtq yet the G/Z VQ crowd chooses to spend $600-1000 on piggybacks/flashes to make close to the same gains.

 

I have the S-afc2 made by apexi. I had an exhaust and intake put on the car and something was wrong, but when they put it on the dyno i was only getting 193 hp at the wheels. After the tune i was getting about 245 at the wheels just with that tune. So it obviously helped me out alot....not many people had that problem that i had though. So to answer your question im not sure what the difference is between the 2 really besides the obvious. The apexi only does air and fuel and the other piggy back system does that plus more. All the gains that i have been seeing are from the AFC though.