Ok from what I gather from about 2 minutes of searching, the piggybacks adjust your air fuel ratios, along with other things. Now the ts and jwt ecu upgrades have presets in them that control air/fuel along with an extended rev limit. Do any of these piggyback systems(vafc, eu, ect.) offer an extended rev limit? I would like the adjustable air/fuel along with the extended rev limit, as I'm sure everyone else does. Am I totally in the dark about this? Please shed some light!

 

EU is suppose be able to do both.

 

anyone have any personal experience with the eu? I think i read something where it was supposed to, but never any hard facts.

 

Check the boosted forums.

 

To say that a piggyback adjusts your airfuel ratio is not entirely correct. They generaly alter the aiflow signal to the ECU in order for it to calculate a different injector pulsewidth. So they do alter AFRs, albiet in a roundabout fashion. You also need to verify any changes you make with a wideband o2 sensor. So it is a bit more complex than plugging in a desired AFR.