Rebuild, then Streetport,...Turbo?
 

Ok um I'm not really sure on selling my car, and getting an S5 OR, Keeping my car and doing a rebuild, Streetport, and a nice small turbo setup. but I'm not sure what kind of turbo. I've heard of people using small mitsubishi turbos. like a big 16G or an 18G. someone told me that I should use a Garrett T03 turbo... That would be nice but I don't have upwards of $600 for a turbo. I know you can find small mitsubishi turbos in a junkyard for like 100-200 bucks. ANyone have any input on what I should use?

Just sell your car and buy a turbocharged car if that is what you want. A Turbo II usually only sells for about $500 more than a comparable non-turbo car.

If you are short on cash then simply rebuilding your current engine may be a better choice, and then you can upgrade later when you have more money. For those with money issues, a simple car with a good engine is better than a fancier car with lots of issues. I personally like the non-turbo S4s just fine, as they are excellent sports cars as-is.

Beware of the "cheap" turbo sucker hole. Sure, it sounds cheap to simply pick up a used junk yard turbo for $200... until you realize that it will require a custom manifold to fit on your engine... and a custom downpipe... and oil/coolant plumbing that is way more expensive than you thought... and larger fuel injectors... as well as an upgraded fuel pump... plus ECU modifications... and probably also an upgraded radiator... and then the turbo will need a rebuild because, well, it is a junk yard turbo, lol,... get the picture? ;)

If you are not ready to end up paying more than buying a TII car, doing all the work yourself, not having a car for a while, even years.......

Buy a whole TII car, from current experience this is the best way if you only want a car to have a turbo.

If you a ready to do all the work, dump loads of money into small miscellaneous items, and have a deep learning experience. Keep the car, rebuild and upgrade as you can....

16g or even the 18g turbo are too small if I remember.
Its not too efficient for a rotary engine, somewhere in the mid 60% I remember reading the map somewhere.
The rotary sucks up lots of air, way more then a 4 cylinder. which the 16g and 18g are suited for.

As others said, piecing together a turbo kit is a whole lot of headache and money spent on it. Its easier to get a turbo engine swap or buy a turbo II

Keep your GXL and get a turbo car later.

I agree with all others that have told you to buy a TII or do a TII swap.

Hehe...Big. Medium sized turbos on an RX-7 is a GT40, T4R, T4 based 60-1, etc. Big turbos on an RX-7 is a GT42R, T70, etc.

The 16G and 18G are pretty small turbos and fairly "old school". Just pull up their compressor maps (I have no idea what turbine options these turbos have) and compare to something like a GT35R.

T3 is simply a line of turbos, referring to the turbine side. There are T3 turbos that wouldn't make the power a stock HT-18 turbo would make, and there are T3 turbos that would put down 400HP on a rotary.

$600 for a brand new turbo is a bargain. The 35R, which many (including myself) consider to be the perfect turbo for a street driven 13B rotary, starts at $1400. Remember, that is only the turbo. You still need a manifold, fuel management, intercooler, exhaust parts, etc.