There really is no single most effective way for performance cheap. Anyone who tells you there is, either is trying to sell you something, or doesn't know better. But if you're looking for cheap upgrades try the following:
*Remove the AC unit (Thats what the T-Tops are for)
*Upgrade the air filter (Either K&N or there is an regular air filter you can retro-fit onto your ZX that works the almost as well as a K&N for about $5 US, If want to know more let me know.)
*Better plugs and wires
*Advance the timing
If you want to do it right, it's going to cost money. If not, your engine WILL suffer long term. The best thing to do is pick up a MotorSport catalog (It's free, and you can order it off the web.), as well as some other performace catalogs, and figure out what you want out of the engine. Then buy it piece by piece. No one goes out and drops 10-20K on an engine in one chuck. (Not unless they get paid to play with it.) Take your time and put it together right. You'll be happy you did.
with a car like yours, i would do an exhaust without a header and a filter upgrade. putting a header on your car will be a waste. you will see very little gain, much more noise, and it will cost you almost as much as a good exhaust and filter. and on top of it all, the job is a royal pain with all the emissions equip. on an 83. if you're just looking for more performance, the single most effective bolt-on part is a 411 rear end, which i think can be found in late 80's 200sx's.
with a car like yours, i would do an exhaust without a header and a filter upgrade. putting a header on your car will be a waste. you will see very little gain, much more noise, and it will cost you almost as much as a good exhaust and filter. and on top of it all, the job is a royal pain with all the emissions equip. on an 83. if you're just looking for more performance, the single most effective bolt-on part is a 411 rear end, which i think can be found in late 80's 200sx's. this will give you more acceleration without much of an increase in cruising speed rpms over the 390 unit you probably have now.
OK! I had the filter in mind....new wires and plugs as well, and the a/c is already gone.
What is MSD?
The exhaust is manifold - pipes - cherrybomb
I live in canada, not a whole lot of emissions equip up here.
The rear end thing isn't an option....i have to be able to do all this myself, and i'm not a brilliant mechanic....yet
I have a 1980 zx n/a and I just put the Jacobs Magnumteam ignition system on it. The difference was very noticable. I also cleaned the fuel system and injectors with a Carbonclean machine. I have the k & n filter on order and have found a shop that will custom make a 2.5 in mandrel bent exhaust for me for about $200. The Jacobs system was $400 and the filter about $45. If you don't have the bucks to do it all, go with the filter and then the exhaust when you can afford it. The fuel system cleaning made a big difference on my car. Good Luck.
I made when I was tinkering with low HP Zs was to swap out the standard rear for one from a 300ZX Turbo 87-88 model with 3.7 gears and LSD. That will be the biggerst seat of the pants change you can make to the car in my opinion.
You already have a 3.7 or a 3.9 diff. A Limited slip will not be of much help to you yet. I know I have said this quite a bit here tonight but if you need new tires anyways, changing tire dia could give you 5% more torque. Switching from a 195/70/14 to a 205/50/15 can give you a 4.5% more torque!! THIS IS FREE TORQUE!!
I know some people will say ARE YOU NUTS? TIRES ARE EXPENSIVE!!. But What I'm getting at here is that you NEED tires, we all do so when you do go to get new tires, if you buy tires with a smaller diameter you automatically increase TORQUE!
Now as far as engine mods go I recommend headers and a 2.5" dia pipes with a high flow cat(if required) and a high flow muffler.
My bad... Just re-read it and you are right...He has a 3.7 or 3.9. I still recommend a LSD (Limited Slip Diff) as it puts the torque to both wheels and we did comparison launches with the same car and two different Diffs, one LSD, one Open and the LSD with the 3.7 was quicker than the 3.9 open rear.