i once had a 94 nissan hardbody p/up . 2.4 auto, and the modifications i did that made a big diffrence is
1) remove air filter top(two wing nuts)and replace nuts w/out top
2) remove eng.fan assy. and add an electric fan.
3) remove 2 after cat mufflers and install 1 freeflow muffler.
i did these mods and my auto pick up was pretty quick,also they are cheap mods,and no turbo required

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