my friend wants to add some HP to his Altima. ive recommended a CAI, new exhaust piping from the headers back, and a performance ECU/Chip. anything different he could do? hes got about $1700 to play with. in his own words: "i want to be able to spin the tires a little bit", "i want to add about 20HP without making it unreliable" also it should be known that he has 18x7.5 (heavy)chrome rims on his car with a 2" drop. he refers to single canister performance exhausts as "potato guns" so hes looking to put a dual exit pipe on it.