Next thing to do to a FC N/A
 

Hey ive got a bit of time on my hands now that school is out so ive started working on my pretty much stock.
Ive taken off the cat and put in a down pipe and a CAI. Then i put on some FD wheels and potenza tires.
I'm looking for help for some more power with out boosting.

Stand-alone EMS tuned properly. With the EMS you won't use the AFM so get a K&N filter. I don't like the cheap no name stuff. 3" PVC pipe and some pipe clamps will let you adapt it to the snorkel tube(black piece from the AFM to the throttle body).

Remove emissions related items. Do a search, its here somewhere.

Long primary header(my preference anyway). Others will scream true duals but I'm not convinced.

And the list goes on and on.

A few ideas
 

4.3 (or higher) final drive ratio
Apexi SAFC or Stand Alone Engine Mangement System
Pineapple Racing 6 PI Sleeve Inserts
Port Matched Intake Manifolds
Mobil 1 75W90 Synthetic Gear Oil or Redline Oil

For other ideas check out my Repair page:
http://my.erinet.com/~cbrinega/

A cheaper way to go is maybe to even get shorter tires/wheels so that you don't have to change the rear gear ratio. It effectively does the same. Used 15x6.5 BBS vert wheels are ultra light and can fit 225's on them.

Going to 4.33 or deeper will cost in excess of $700 in parts alone and probably $1K when you are done.

Going with a stand alone engine management system will cost some bank and probably only yield 15-20hp. $500-1000 including tuning.

You are now at the point of diminishing returns. I'm not trying to be pessimistic.... but just trying to be realistic.
Is 30hp worth $2-3K? Every 100lbs is 10hp..... note to self. Aluminum hood saves 20lbs+....

You should put some money into your suspension and make the RX-7 do what it does best...... handle. ;)

BTW- I'm selling an S4 T2 differential with T2 halfshafts and custom driveshaft for n/a 5speed to T2 diff. $350 plus shipping. If you don't have LSD this is a cost effective way to get it.... plus you get the benefit of the Turbo 2 8" ring gear.

-GNX7

are you still running stock ports?
i'd second the motion for a stand-alone ECU, but in my opinion, it doesn't make any sense if you're running stock ports. get a decent streetport and full exhaust (with header). get a lightweight flywheel and if you can afford it, have everything balanced. that should probably net you 20-30% power increase, depending on state of tune.

oh yeah ... a note on the Pineapple inserts ...

now keep in mind that i have never used them, so i'm not taking one side or another on the issue, but i figured you should read this ... Pineapple Sleeve Questions