Ok, so I've got an '88 GTU N/A. And Im considering doing one of two things to it. Either completely swap out the S4 for an S5 Tii or do a complete aftermarket turbo kit from like Greddy or something. Whats the benefit and downsides of both?

 

I've heard the S4 electronics do not work w/ S5. So you should stay in the same series when doing the swap, unless you want to change all the wiring.

Please post the link to this Greddy turbo kit

 

I wasnt specifically looking at Greddy, it was just an example.
But here's one for an FC. http://www.vividracing.com/catalog/p...ducts_id/22921

 

Not for an NA

 

If you are going to swap the S5 TII stuff into the S4 NA, then the best and easiest way is to use a standalone. The electronics between the S4 and S5 are totally different and using the stock stuff means you will have a mixture of S4 and S5 mechanicals/electronics...

There are no aftermarket turbo kits for the NA RX-7. If you intend on turbocharging the NA engine, you will be fabricating everything to do so.

 

Ok, Im still new to this whole turbo thing. So I guess getting an S4 Tii would be my best and changing out the turbo, adding an intercooler ect. would be best...

 

How about looking for a S4 TII engine, like you said, asking for a compression test from the seller, swap it and make sure it works properly, and then sart thinking about mods.