ok so @ stock

whats the diff. b/w s4 and s5 na motors

 

this has been covered and you can search it, but on the top of my head different weighted rotors and the intake and dynamic chamber is better on the S5.

 

how do you search it? I just tried; series4 vs series 5 / s4 vs s5 / s4 s5 / series four versus series five / 88 compared to 89 / s4 versus s5 / and a few others.. No results for most of them.

 

And as far as I know, the S5's have a redline at 8000 instead of 7000. They're about 20 more horsepower between the two types of engines on S5.

But what they did to gain that horsepower; I don't know what or if any advantages the S4 N/A or turbo (if there are any that exist) exist over S5 motors. I'd like to know though. Would hate to think my engine won't ever surpass a S5 engine with duplicate mods in any way shape or form.

 

https://www.rx7club.com/showthread.p...ht=86-88+89-91

 

If you ever get a rebuild you can machine the .5 pounds on each rotor to match the S% rotors. I forgot what gave the N/A boost in power, but the turbo went from a twin scroll, to an independant twin scroll turbo, that modification can be made by swapping th eturbocharger and header as well as a few small things.

 

s4 = lower comp rotors, different intake setup, n/a have vacuum induced 5th and 6th ports, diff seats, the body trim on a s4 has teh groove in the middle, diff lights

s5 = higher comp rotors, more efficient intake setup, electronicly opend 5th and 6th ports, better seats, bodry trim has groove on lower section, diff lights

 

There is this thing and its called a FAQ at the top of the page really really helpfull and tell you basically anything you wanted to know.

S4 has as stated before, lower compression non VDI intake, vacuum operated AUX ports, steel hood, less power, redline starts at 7.5k(may be incorrect on accual number but its not 8k, OMP was mechanical, Different ECUs, interior was different in many ways, and alot more.

But how the hell does an S5 have better seats thats a matter of opinion IMO. I love my cloth blue sport seats.