whats the most mods the factory ecu can handle without having boost and other limiters

 

it all depends on how much luck you have when plaing with fire

with an FCD and no other things 10psi is the SAFE limit

 

You don't mention what gen you have, but if you have an FD, check out Wade's page. He has done wideband testing. As you can see, you can pretty much run atleast an intake, exhaust, and downpipe IF you restrict boost to 10 psi. If you are willing to run low 11s A/F ratio (what most people shoot for), you can pretty much run all the bolt-ons at 10 psi.

http://www.newwave.net/~flanham/wlan.../3modrule.html