With little mods to car you can change how much air the computer thinks the car is getting.

Can not control timing, boost, more fuel for nos, can cause poor idle, you are not fixing the problem just trying to trick the ecu

A piggy back is ok if you have little mods done to your car, but if you have a turbo, nos, or anything else you need to retard the timing for it is a waste. You might have to install up to 4 different types of controllers and spend way more than if you just bought a stand alone engine management system to begin with. Save money get a Stand Alone Engine Management System!

The playback feature and 50% fuel enrichment. Also ease of use

Figuring out the correct wiring

Great value for dollar..the overall features it offers are more than worth the price.Mounting the unit is abit troublesome

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Field Sfc and SDS the apexi unit is the middle ground.

-Control Fuel, especially when you have bigger injectors like 440 cc injectors.
-Unit looks great and compliments the interior.

-Hard to see during daytime even when set at the brightest setting.
-Needs more options
-Worthless when you have 500+ cc injectors. You'll need an aftermarket ECU.

This is a great product. Great piggy back system to adjust fuel settings. Great when it's used with bigger than stock injectors because you will run rich. And the engine will stall out or idle poorly. With the S-AFC you can tune it out. But with REALLY big injectors, this unit is worthless.

Similar Products Used:

Field SAFC - Never used it. I heard you can only control up to 30% compared to Apexi's 50%