wattup wit da turbo?

time for a re-tune on a dyno. take it to a local speed shop that has a dyno and have them dyno tune it.

In addition to a cpu flash, you may need to beef up the fueling system... I'm not sure if you've thought much about it, but 6 psi is on top of atmospheric pressure... 6 psi doesn't seem like a lot but that's 40% more pressure in the same space... means you need ~40% more fuel, if you can keep intake temperature down... PV=nRT... It sounds like you may just be starving the engine... I'm sure there is more information to be had on a rotary fan forum of sorts.

So how about if we get bigger fuel injectors?

you should tune the e-Manage that came with your turbo system if you havn't yet im pretty sure all GReddy turbo systems come with it dont know much on the rx-8 but the guy above could be right too

u can do that but ur still going to need a tune... personally i'd tune it first if they say its getting starved then yes i would most def. Any local speed shop should be able to hook up a air/fuel meter to read it after they tune it. but if u get bigger injectors you also will need to look into getting a fuel pump that can supply the new demand to the injectors. I'd take it to a speed shop that u think you can trust and that does work on imports such as those. a tune should be roughly anywhere from $400-$500 depending on the shop.

could any of the problems have 2 do with the RENESIS motor itself, like for example the exess compression due the certain revisions made by Mazda (e.g. the side intake port)?

im not all that well knowledged in rotary motors myself... well practically any imports, but its possible compression has to do a big part in air to fuel. when you up the compression in the motor with air u also need to bring in more fuel to match with it. i mean when it comes down to air and fuel thats something that should be left to guys who have the experience and tools to read it properly and tune it. i dont even mess with my fuel map myself. There's alot of risk in it you burn to lean u can put a hole in a piston, if u burn to rich u just waiste gas and horsepower, general rule of thumb its always better to burn rich then lean.