Basic Bolt Ons RX-7 = how much hp?
 

If the car is running right, all the filters are new and the hoses are Tie wrapped...how much horsepower would a good running FD3s have with these mods:

Apexi Power Intake
Downpipe
Exhaust
Apexi AFC
Blitz SBC boost controller

What PSI is it safe to take it as...how much boost will the car run without the boost controller, assuming the free flow mods will raise the boost. Also, is it alright to do these mods without an aftermarket intercooler?

Without fuel, you wouldn't last very long. I'd say substitute that AFC for a Power FC, then go from there.

I'm asking for my friend and he doesn't want to spend too much money. He basically wants to go BPU without blowing up...but he has a warranty on the engine, so he doesn't care too much. Power FC would be kind of out of his budget...

check out my threadhttps://www.rx7club.com/vforums/showthread.php?s=&threadid=19653

He'd be MUCH better off spending an extra $100 and getting a used upgraded ECU over the AFC. With those mods, the stupid fuel cut of the stock ECU is still present and will limit the amount of boost. Plus, he'll get more hp since the AFC only adds fuel and won't adjust the timing. In fact, since he's keeping the main cat he'd be better off saving money by skipping both the boost controller and the AFC and getting the upgraded ECU instead.

Still, the best solution is just to spend extra to get the fully adjustable PFC(esp. if he wants any addtl. mods in the future like a midpipe)

W/o a boost controller you'll probably be hitting around 11-12 PSI on a warm humid day and around 14 PSI on a cool night. Its ok to do these mods w/o an aftermarket intercooler, but you shouldn't raise the boost more then 12 PSI until you get an intercooler upgrade because the stock intercooler sucks.

Thanks for reminding me about the fuel cut. I guess a BCC or FCD could eliminate it though...where would he find used ECUs?

you can try www.thepartstrader.com or you can post a wanted thread in the for sale/wanted section.