I have the cold air intake, performance mas air flow sensor and air foil.
Now the question is
what is the best exhaust system to put on my 94' Z28?

 

Depends on who you ask and how much dough you want to through down.
Good ones:
Borla, Corsa, GMMP(all kinda pricey)
Hooker, Magnaflow(mid range)
Bad ones
Slowmaster(pennies on the dollar)

I know i'm going to get yelled at for this, but its the way I feel.
Flowmasters sound ok, but don't flow for ****.
All of the good ones flow very well AND sound good. Some like the Borla are even adjustable.

 

welcome to the board. ive been here awhile and this is what people will usually say. Borla, Hooker, SLP loudmouth, are popular im sure theres another i just can't remember. magnaflow? flows are cheap and good (at least I think) as long its a 3in catback. either way get a 3 in catback exhaust. Then people will say get headers. Hooker Longtubes are great if you don't have to worry about smog or ground clearance. BBK isnt that great, flowtech is horrible, Macs are good, slp is good as well. Do a search on this board because this topic has been talked about forever. Every new person on the board asks this as they rightly should. Im no expert just listen to what every1 says.