A/F as the single pop program was made to measure all the air and this is what your still doing by running the Selin on add. When you get over 500 HP you have maxed out the voltage reading and to go higher requires splitting the values in half in the chip and going to average on the Selin translator. The single pop program has a VOLTAGE limit of 500 HP. This got confused a long time ago and people thought they would not make more power until over 500 HP. The reality is a totally stock car can benefit from a dual pop power wise. At 500HP you have to go to a dual pop because of the electronic limit. The issue with most of the dual pop programs out there is they were written for some kind of odd way to measure one side only. When you measure both sides with 2 meters I have found it changes the readings the ECU will get for MAF voltage. The 2 MAF is the best way to do it, but the issue is most of the chips being sold are not as good as they could be running a dual pop program because most of the chips were made for a different set up that required some funky tuning to get right for a set up that just used 1 MAF and a dummy MAF. Since we tune cars here all the time we see different programs with different configurations and the cars running a dual maf set up and a dual pop chip require more tuning than they use to and none of the old programs for the old set ups are correct, but they work. Chips use to be different only based on injector size and single or dual pop and transmission. We find this is not enough parameters today with what is now available. The things that effect the tune the most besides injector size with the parts available today are exhaust size, intercooler pipe size, and the type of dual pop set up. The rest of the things are smaller changes, but all of the listed can change the program more than some think.
