Originally Posted by 97idelentra

I have a 97 Hyundai Elantra and I'm curious about what upgrades I can do to it he has a 1.8 liter in it.

Intake, exhaust, header, cam, bored out intake manifold and throttle body, plugs, plug wires, built block (pistons, rings, etc), nitrous, turbo install....



if I could do head swaps off of other Motors? If so which ones?

It'll cost you more money to drop in a different engine or a head versus just building the one you already have. If you really want to swap engines, then a 2.0 would be the easiest, minimal cost and time. But don't expect any kind of a big power boost.



if I were to swap Motors what would Bolt in?

You could drop in an older 4G63, from a Mitsubishi Eclipse, which has been done on the older Elantras. But again, expect it to be a bit complicated, you'll need a stand alone tuning opion like a Haltech, and you'll be doing a lot of fabrication (engine mounts).



Is there any difference between a 1.8 wiring harness and a 2.0 wiring harness?

Pretty sure they are the same, but the ECU is different.



Can I upgrade the injectors?

You can upgrade them to anything you want, but you'll run rich unless you tune the engine to handle the extra fuel. Upgrading injectors are only needed if you're doing forced induction (large nitrous shot, turbo or supercharger)