I meant MAF (mass air flow) Not MAP my mistake. I must of typed it wrong,Lol..I believe the Fast XFI is speed density too,the same as the AEM , However due to the EZ tuning it may not compute all the sensors and get maximum tuning 100% ,maybe 95% or 98%? .I am not sure which ,I believe the Mopar AEM can. The SRT division developed the mopar AEM as a solution to run the Gen 3 hemi .Maybe the Fast XFI system is better because its user freindly and easier to tune ,like I noted. I am sure someone can chime in.