Hi, new to the forum here. This place seemed like the better place to get some information. It is a combo that i came up with to use some existing parts and put together something more easily swappable into an rx8. Basically i have a couple engine's worth of parts from fc car's that are good usable parts. I've got a set of housings in really good shape and good rotors, e shafts and counter weight's from an s4 and s5 n/a and also can get a set of tII rotors pretty easily if need be, but i figured that the s4 n/a rotors would maybe be fine for the power level i am looking at, but i haven't i guess seen really anyone using these parts together or how well they work together or if the port timing between the exhaust on the fc n/a housings and rew iron's would work well and also if the side seals and corner seals on the s4 rotor would run over the intake ports fine. My goal is to put together something that will handle 300, maybe 350 more reliably than a renesis that will more easily go into the rx8 than the s4 or s5 engine. Basically rew iron's, s4 housings and than the rotors, e shaft and counterweight from an s4 motor. Any info on this would be greatly appreciated.

 

So you're asking how difficult it is to swap s4/s5/s6 engine combo into an rx8? REW irons will dictate the engine footprint/mounting/etc. REW engine swapped threads would be your friend here...

rotor compatibility between S4/S/S6 shouldn't be an issue, but I'd question that on rx7club.

 

I have done a decent amount of research on what is involved putting different motors in, which is why i picked the rew irons because of the mounting point's. Mainly just trying to see if anyone has experience with using s4, s5 and s6 parts together i guess without having some kind of issue like you'd run into using the s4-6 rotors in a renesis where the side and corner seals could interfere with the port's. The way those rew adapters move the mounting point to the back of the engine sure is nice for fitting a header in there and not having to work around that renesis mount on the passenger side.

 

You say you have REW irons in the original post with s4/s5 housings. But you now say you have REW housings. Can you bullet point exactly what your're wanting to use? More quality the question, the more quality your answer will be.

People have ran s4/s5 irons in REW blocks plenty of times due to their rotors being stronger and lower compression for higher boost. What I do not know is what other modifications (if any) are needed. These are rx7 specific parts, a large majority of the rx8 community will be clueless more than likely. And rx7club gets a lot more traffic than rx8club.

 

I will edit that last post because that is confusing that i typed housing, i am talking about rew iron's with s4 or s5 housings, rotors, e-shaft, counter weight's, with a renesis front cover. I have asked around a bit over there just i guess posting here since maybe someone did something similar to more easily adapt into an rx8 without buying the entire rew engine.

 

It really depends more on whether you are keeping the stock ECU or going haltech +$3k or more. Or find a second hand adaptronic.

I think the only reason to keep the rx8 front cover was for the timing wheel. Which I think you can get the FFE RX8 trigger wheel for the REW....not sure if this works with the stock ecu. Problem with the Rx8 front cover is that you need to modify the cover itself or the front counterweight to fit.

 

I plan on using as much of the oem system's as i can, i don't see any of them as being a limiting factor to what i am trying to do. I would put the renesis lower and upper intake manifold on the engine with rew ports using a pretty simple adaptor plate and keep it rather just stockish in that aspect with some bigger injectors and aftermarket rails to eliminate all that oem stuff for the fuel system. From what i have found the stock ecu is flashable which should allow timing and fuel tables to be changed. I don't really see much off the stock stuff as a restriction as long as the fuel system is upgraded so that's why i plan on reusing most all of it if i can make it fit. I need to do a lot more research on just how tunable the stock ecu actually, but i have seen other's talk about using mazaedit with a tactrix open port which from what i have gathered should have no problem dialing in the timing and fuel for a boosted application and scaling in the larger injectors. I am going to do some more research in that department but If it works than i'd go that route.