I've looked into possibly doing this but have only found info on converting a n/a to a tII. What I'm wondering is it possible to put s4 n/a rotors into a s4 tII block to make a higher compression s4 version of a s5 tII? Also would the whole rotating assembly have to be swapped or if ones lucky to have same weight rotors between the n/a an the tII just swap the rotors?

 

to make this simple..
you can get a blow s5 block and swap over your s4 na rotating assembling front and rear weights.. the shaft is all the same so it doesnt matter..

also you could do a s4 block.. and swap out the housing but they have to match this is very important due to the fact that the spark plugs move up a few mm to change timing.
i think you can inner change the irons

 

The location of the spark plug holes does NOT change the timing. That is controlled by the ECU and CAS.

The rotating assemblies are balanced within the series. TII vs N/A doesn't matter as long as all the parts (excluding the e-shaft) are S4 or S5. The compression ratios are what's different between TII and N/A.

 

Yes. S5 TII run 9.0:1 cpr. Just like the FD. Same rotors. S4 n/a rotors are heavier but the extra weight will help the car launch.

The rotating assemblies are the same within series regardless of if the parts are TII or N/A. If you use s4 rotors you will need s4 front CW and S4 flywheel. If you use a N/A tranny you need a N/A flywheel.

It sounds like you already have a S4 TII tranny so if you use S4 N/A rotors you need a S4 front CW (TII or N/A) and a S4 TII flywheel.

 

make sure the Irons are TII though or you will have the NA aux ports on it.