[Celeriman]

I would like to know if there's any engine/exhaust modification I could do to improve acceleration on a Hyundai Accent 2001, Automatic transmission (1.5L)? I could spend around 750USD.

Or adding a CAI or performance exhaust is it recommended?

 

[VALKYRIE YB70]

A good CAI & custom free-flowing cat-back exhaust system could give you around another 12 crank b.h.p..

Nick.

 

[DynastyAccent]

Underdrive pulleys, also. I hear those free up some torque, and you'll be wanting as much of that as you can with an automatic. Also, I wouldn't go too big with the exhaust. I went from stock pipe with 2.25" welded on after the resonator to a header, no cat, and 2.5" piping on my 1.5 sohc. I noticed much less torque in the lower RPM range, but it screamed once it got past about 4000.