the ignition timing and the physical location of the spark plugs have nothing to do with each other

 

Well that's good to hear, I'll just use the S4 stuff, cause I can't find the S5 hub and timing pulley

 

hmmm. whats up with using s5 turbo irons with s4 turbo hoisings? are s5 turbo irons different than s4 turbo?

 

thats s5 turbo irons with s4 turbo rotor housing*

 

some people tend to believe the series 5 turbo irons are superior with thicker castings, which isn't true. only a small percentage of series 5 turbo engines had the thick cast rear iron.

aside from that s4 turbo and s5 turbo irons are virtually identical. the port openings are a hair larger on the S5 versus the S4 but the difference is unnoticeable to the engine.

 

I see. I was thinking that s5 turbo irons had a different intake open and intake close than the s4 turbo irons. I was thinking that could be the reason why the plugs are in different spots on the rotor housing.


so using s4 rotor housings on s5 irons isnt a big deal? just as long as you dont use one s4 rotor turbo housing withone s5 turbo rotor housing.

what about exhaust open and close? are these the same on s4 turbo rotor housing and s5?

 

yes to all.

 

One improvement you can make is using an S5 front and rear irons. Not power wise but strengh especially the rear iron. For Turbo, S4 weak point is the rear iron whereas the S5 has the reinforced rib at the oil filter pedestal. The front iron has a wider landing for the front cover o ring. Mazda did make some notable improvements on the iron.
It was noted in Mazdatrix years ago about the o ring slipping out from the narrow S4 landing and advised not using the teflon ring.

On my friends S4TII, rear iron cracked right at the oil pedestal . It was fine until he got it tuned for about 350rwhp, then it was a geiser. Never imagined THAT much oil could come out of a little crack.

 

the additional rib doesn't really add any integrity alone without the thicker casting. those who think it really does much of anything aside from moral support are misled.

 

I'm sure it has thicker casting as a half inch rib alone
up the pedestal won't support THAT much stress.