Just heard about the Smarty. I have a 5 year old Diesel Dynamics True Torque Power Module (DDTT) box that I believe does fuel and timing (made by Edge, like the EZ with slightly different specs, supposedly optimized for DD's injectors). I run DDII's for the sake of discussion. My question comes from reading threads about "stacking" comps, etc with the Smarty. I read the directions for the Smarty off their website and of course it say's disconnect everything else as it will do all the work by re-programming your truck's ECM into a fuel/timing box. Since "we" love to experiment (especially when told not to), I have noticed that some of you have already "stacked" the Smarty with comp's and other boxes. Wondering if anyone has any data on exactly what is happening with: The Smarty alone. Smarty stacked with various products (EZ, COMP, VA, etc). A chart would be fantastic but I am really trying to determine what exactly is happening. Totaly understand Smarty only, but what happens when you stack? If the Smarty code becomes the new "stock" baseline, does your add on box further increase timing/fuel on top of this or is there a comparison and subsequent compromise sent to the VP44? I make my living (like most of us?) with my truck and don't want to screw anything up by experimenting. Seems a number of guys have already gone there so looking for some info and I know there is someone out there that knows all of this like the back of their hand. .