engine differences NA
 

What are the differences bewteen s4 and s5 na motors, besides rotors and ports maby?? and what would be needed to swap from s4 to s5 ? Last would it be feasible to get t2 rotor housings and streetport them and run on street ?? in an na motor??

i hear that if your going to do a port (street port ie) that you should use high compression rotors like from the renisens(spelling) or from the s5. personaly i would just get some s5 rotors and do a street and exaust port. that is what i would do. to swap the rotors you would more than likely need to do a rebuild.

Ok thats what i was thinking. But i thought i remenber some one saying that the s4 manifolds are more suited to a street port???

personaly what i am going to do is keep my s4 housing and manifold and everything but the rotors and go with some s5 rotors. and i am going to do a tb mod and also a new exaust system. but as far at the s4 manifold being more suitable for the street port than an s5, i really don't know. i don't think there is much difference(correct me if i am wrong cause i still consider my self a newbie). hope that helps.

hmm this all sounds interesting, how much for port job/rebuild/pair of s5 rotors would be? GRAND TOTAL?

Recently ppl have been saying that S5 stationary gears are hardend, I belive they used a slightly better coating on the iron housings on the S5, not sure though.
Things that I can say for sure, different counter weights, the egr was moved, and a couple of things that I can't remember right now.
And S5 rotors are going to cost you, it would be cheaper to buy renesis rotors and have them machined to accept older style 2mm apex seals.

eh, actually this subject has been asked many a time. did you search first?

well i am going to try to port it my self. but racing beat charges like 350-450. and the rebuild kit is about a 1000 and then i would also do that my self. i don't know about the s5 rotors but i think that if you didn't catch them on a good ass find then you would look at atleast 450 a rotor. i think that mazdatrix sales them.

S5 NA rotors are lighter weight, S4 NA are higher compression

i do try and search everything before i post but that stupid 3 letter word limit thing really pisses me off

Partially wrong. The S5 rotors are both lighter in weight and higher compression than the S4 rotors.

that is what i thought but does anyone think it is worth it to swap s4 to s5 na or just go t2 swap??

The higher compression ratio between the S4 and S5 rotors is not a great place to look for power gains. The power gains are minimal compared to the price of getting all of the parts needed. Renesis rotors would be cool, but I'm sure those are pretty damn expensive aswell.

I have to at least partially disagree with this. If you're porting for more power up high, going with a lighter, higher CR rotor will definitely improve your high-RPM performance and should raise your redline a bit.
Also, Renesis rotors are quite a bit cheaper (new) than any previous 13B rotors. Mazdatrix sells older-generation 13B rotors for ~$500 each and Renesis rotors for ~$300 each. Granted, unless you have a good mill and know how to use it you'll probably spend at least $200 per rotor having the apex seal grooves deepened so the cost should come out pretty close.