mods on 1y

[professor]

hello
i have one seat ibiza 1.9D motor 1y (non-turbo). i have some mods for performance on my car like: governor mov; timing advance; more debit of diesel; intake manifold polished within; egr off; catalyst off; exhaust line in steel inox with 53mm in diameter; pan end of seat ibiza gttdi of 110cv; injectors of MB300TD.
i would like to give more power without turbo or compressor. which more mod can i do for performance?

[honda_is_the_best]

nitrous? 

you have a pretty complete list of mods there.. maybe some 2.5" exhaust..  hows the intake box? got it opened up to flow decent? as long as you can get air in and out of the engine as easy as possible, you are doing good..