For better acceleration, you can do these minor things first.
get a 4-2-1 extractor with 1.7" piping. then change to an K&N air filter and intake(open pot or drop in up to u).
This might help improve acceleration
if your car is second hand or u have just bought it and find it not very smooth, you can clean yr throttle body and oil lube to remove impurities. techincally it does not improve power and acceleration, but if yr car is of old age, it wise to do this as you will feel a slight improvement in acceleration. AND u will definately feel that yr engine is smooth. it woud almost be like a new car already(the engine im refering to).