Ok so can someone explain to me the diff between the S4 and S5 side housings? As well as the S4T2 and S5T2 side housing? Looking to get new aluminum side housings for the 13b, but im not sure the diff between S4 and S5. If i ever figure it out, it'll be a turbo build. Also, after looking on Mazdatrix, they had the aluminum side housing for the front rotor and the rear rotor as well as a front, intermediate, and rear housing.... WTF is all that about? Someone help me out, im confused and my head hurts

 

im not sure what you are asking in the second question, but there are three cast iron housings in a rotary (front, intermediate, and rear), but im sure you knew this. and about the housings, call mazdatrix and ask them. theyre awesome and three hours behind so theyre open late. i think the dif is that the s4 is a 4 port and the s5 is a six port, but id call and ask anyway...

the number is 1-562-426-7960

 

only the original cosmo had production aluminum sidehousings

 

s5 have biger intake ports on bowl area. s5 rear iron come in a thicker dowel area option (better but harder to find)
s5 iirc have biger secondary ports. and s4 primary ports. but porting will make it pretty even.
i suggest going with the s5 irons if u can find them especially the ones with thicker dowel area on rear plate.

 

There is now an aftermarket ALLUMINUM (LIGHTWEIGHT) option available. Its a bit pricey at 658 a housing. But They have alluminum rotor housings and front, intermediate, and rear housing for the 13b. I guess i was super tired when i came across it cuz after looking at it again it makes total sense. I was looking at rebuild options for something i might be toying around with shortly. But with more than 3 grand just in housing.... it might be a slow process (i havent even looked at the light rotors yet). They make S4 and S5 housing which is why i was curious as to which housing would provide better performance opportunities. Also, the alluminum claims better wear and longevity than the origianl housing found on the stock 13b's.

 

link i've never seen that

 

S4 T2 is 4 port and S5 T2 is also 4 port NOT 6 port ! There is no Turbo Rx7 that comes with 6 port config from factory !

 

S5 irons are stonger then S4! S5 is far better to use when rebuilding a rotary motor better balance,better parts ,and a little more power.....s5 is the way to go N/a or turbo

 

Agreed with most of the above. the major difference. is the intake manifold attachment. different series of engines had different manifold and port designs.. while some are better then others, not all parts can bolt together. make sure the manifold you are using is the same as the Side housings you choose. also FC and FD RX7 engines have the motor mounts in different locations. so it's not a simple stupid modular slap together affair, but not particularly difficult either.

1989 is your answer <1989 is S4 >1989 is S5 manifold design and HW AFM vs. barn door AFM had a lot to do with it.. the S4 and S5 housings are 6 port if NA and S4T2 S5T2 are 4 port. (like was said earlier all Turbo's were 4 port)

Call if you have any questions
813-333-1100
Tampa Rx7 repair, 1st place.

 

Well I got a Turbo 2 engine (4 port of course) S4 I think,Fully bridgeport ,racing apex seals ,exhaust done and new bearing anyways engine gots power but very loud so i think an s5 turbo would quiet car and still maintain power, but looking to get an engine and like i said i dont knows if is a s4 or s5 how would anyone know, my rx3 in process of been restored So I took engine out and now thinking of getting a s5 turbo instead of a holley, What year is s5, I checked i Think is a 1989 turbo II im i Right, ?>sorry for going back in forth but my spanglish ,,tried my best to make this all english