voodoo box?
 

i have a greddy kit w/ mbc, and msd box and 305cc injectors would a voodoo box allow me to run more boost?

Megasquirt. Use it.

im saveing for a factory five kit right now i was thinking kinda a budget used voodoo if it would help any

What's a factory five kit? Oh yea, I'm a grammar Nazi, so please hit that shit key to capitalize the first word of your sentences. Punctuation helps separate your thoughts. It's the key below "L" and to the right a wee bit. You already found the "L" key, so the period shouldn't be too hard to find.

It all depends on what your goals are. If big power is in your future, MegaSquirt (MS) is the first thing you should buy.

I know this car will never be fast enouph for me so im just looking for somthing cheap to get me buy untill my kit car arives. MSPNP sounds great but i think i will wait to use MS till i set up the twin turbos on my GTM.

No it won't.
The limiting factor to you current setup (assuming you've listed everything) is that you don't have an intercooler. Turning up the boost from the stock Greddy kit without an IC is a bad idea. And if you're still on the stock clutch, turning up the boost will just lead to clutch slippage.

Save money, don't buy anything else for the Miata, don't cheap out on your FF.

And for those who don't know Factory Five is the largest maker of Cobra kits in the world... and they make a few other kits. The GTM is the latest: http://www.factoryfive.com/gtmhome.html

The voodoo box is kind of a joke. For $1-200 more you can have full control using megasquirt.

unless you are getting the voodoo box with a kit i wouldnt buy it. i have one and so far i havent been that impressed, the amount of adjustability is slim at most. save a little more money and go with the megasquirt unelss your money bags then go with the hydra.