what is the best modefication for max power that is under 500 dollars. also keep in mind that my z has all stock parts so far

 

Crawford Plenum, right @ $500.

www.crawfordzcar.com

 

ditto

 

Crank Pulley & Pop Charger...

http://www.performancenissanparts.co...roducts_id=256

http://www.performancenissanparts.co...roducts_id=260

 

I thought the crank pulley didnt do anything?

 

Y-Pipe and Popcharger. The Y-Pipe will give you gains that most full exhausts won't give you. Also, I have heard that the Popcharger will give nice gains without much install. Actually, both of them are easy installs.

 

the crank pulley adds 6-8RWHP across the full RPM range...

 

I thought I read somewhere on this forum about a guy that dynoed his Z with a crankpully and lost some power. But, I could always be wrong.

 

The plenum would be nice, but right now would suck since their are not alot to choose from. Wait until APS's comes out. I know alot of people with Evo's that buy from them, and swear by there parts. As wise as price, if you said $500, I dought you can get cats and plenum for this amount. I guess no one see's this in your post. I still say Y-Pipe and Test Pipes, or Y-Pipe and Pop Charger.