In my opinion the cold air intake system sucks from Motorsport Auto I did'nt notice a change at all in the performance of my 80' NA ZX. If you really want an intake upgrade I would suggest saving your money and making your own.
I made mine out of a stock airbox.. I got an extra from a junkyard and cut out the whole front of it.THen I bent the brackets down so it would be faceing more in were the air would come in.I bought a stock k&n air filter and vwalla.. ram air for 40 bucks..I like it. I just need to paint the airbox another color then blue..lol good luck.
i made mine out of some black PVC pipe and a big ole K&N from the APU of an apache helicopter. My mount looks kinda ghetto gay though. I really dont know if it works better, since I changed the clutch and differential at the same time, the diff was 354 to 390 so that was probably the biggest change that i feel.