well i cracked my block open today to figure out what was actually wrong with it. got a nut embedded into the front rotor. so its garbage now...
i was wondering if it would be possible to just swap out the whole rotating assembly out for the n/a one i have without any issues. the motor i have is a s5 tii and the "new" parts would be out of a s4 n/a. i'd swap the front counter weight rotors e shaft and flywheel. btw im still running a na tranny so thats why i'd use that flywheel

 

I'm pretty sure it would work for the most part. The only thing is you have to be careful if you have any mods. Since the S4 NA rotors have higher compression, you may have to compensate for that with your timing if you're running above stock boost.

 

only "mods" would be no emissions and a cat delete stock size downpipe. and open intake.

 

I'd dial the base timing down a bit then.

 

will the timing makrs be the same with using an s4 eshaft and s5 front cover? just curious if this is one of my hard starting issues

 

You would need to swap the ENTIRE rotating assembly. Front counterweight, rotors, rear flywheel.

http://www.mazdatrix.com/faq/rotorwgt.htm

As long as you keep the pulley and hub together from the S5 (or the S4) then timing marks are the same. If you mix and match pulleys and hubs, all bets are off.