I was just wondering if I could replace a s5 na block With a s4 turbo block, with all the s5 na accessories. and if I could, is there anything I need to know as if it can be a direct fit or would I need to do some modifications.

 

What exactly do you mean by accessories? Do you mean a S4 Turbo long-block (manifolds, turbo, etc) with the power steering, alternator, a/c .etc from the S5 NA engine? Or are you asking if the short-block (just the keg itself) interchanges with the S5 NA manifolds and accessories?

What combination exactly are you trying to perform?

 

basically everything except the intake manifold will fit, so like the AC/PS,Water pump, fan, hoses etc all will go right on.

 

Im just trying to see if a s4 turbo block could go where a s5 na block once lived, While keeping all of the power steering, alternator, water pump and all of that, if that makes sense.

 

so I would have to get a s4 turbo intake manifold to bolt right on?

 

could the s5 turbo intake fit?

 

it does exactly that.

yep.

 

alright thanks so much man.

 

You never answered the above question and clarified what you mean by "block". What specifically are you trying to do? The short answer is yes it can, but the real answer is much more involved depending on what your end goal or what yor're trying to accomplish is.

 

I’m trying to see if the turbo block itself can bolt where the na block was at, so yes To the first question since your second question was answered, I’m sorry if that doesn’t make sense, I’m a little bit new to rotaries as you can see lol.

 

Yeah, still clear as mud. When you say block, to me that means the bare engine with nothing attached to it except the front cover and what's underneath it. So no intake or exhaust manifolds, turbos, etc. Is that what you mean as well?

 

yeah exactly, nothing attached, I wanted to see if the s5 na water pumps, alternator, power steering pump, manifolds, etc. could bolt onto the s4 turbo bare engine.

 

No.

The intake manifold is different and sticks out too much. This interferes in the event you are trying to use the stock manifold and turbocharger. Even if it did fit, the port shape is different between the NA and turbo engines. In the event you aren't using the turbocharger and intend to run it in an NA application, you'll have a serious power loss due to the difference in intake porting and lower compression rotors, combined with the fact that the NA manifold doesn't align with the ports on the turbo engine.

If you want to run the water pump, alternator, and power steering pump from the S5 NA engine on the S4 Turbo engine, that will work. But the manifolds need to match the engine, so NA manifolds won't mate properly to the S4 turbo engine.

 

got it, thanks for the explanation I just needed to clear up some stuff before I walk into a pit

 

Also note that to pair this with your S5 n/a transmission you will need a flywheel for a S4 n/a as the turbo and n/a flywheels are different diameters. Either S4 or S5 n/a clutch should work but the flywheel or lightweight flywheel counterweight combo has to match the series of the engine.

The intake will bolt to the engine but as WondrousBread said the port mismatch will be bad. You could port match/fill the lower manifold as I've heard in a n/a application it flows better. It's some work though because there are areas where the aux port( 6port) runners went on the n/a housings that need to be filled with Devcon and then ported/ reshaped to match the turbo housings. There's pictures on here somewhere I'm sure. You'll also have to completely remove the rods for the 6 port sleeves and seal them up as there is no place for them to go on the turbo engine.

 

alright thanks for the info, also would I have to change out the wiring harness to ecu also?

 

If you're port matching your S5 lower and using all your S5 stuff then no.
If you're using the S4 stuff the answer could still be no on the ecu but you'll have to change some things over to the S5 stuff. The throttle body is one I know of because the TPS and how it mounts is different but you'll need the TII tb I believe. Also need the Oil metering pump hooked up but I think that may require the S5 front cover be used. You can just use your S5 injectors as long as you stay n/a. Also so may have to adjust some wire legnths of some of the connectors on your harness as well. There may be more this is just all I can think of off the top of my head.

 

so if I was converting the s5 na block to the s4 turbo block while keeping all of the s5 na parts like water pump, power steering pump etc. would that still affect the wiring harness?

 

I think it may, as some of the lengths to the connectors may be different on the turbo. You'll still have to solve the OMP issue as the S5 ecu goes into limp mode without it plugged in and the TPS as well.

 

would it be better if I get a s4 turbo ecu with a s4 wiring harness then? Or are the s4 and s5 wiring harnesses completely different?

 

S4 and S5 are completely different.

the S5 turbo and NA are different, but close enough that it can work

the S4 NA and S4 turbo are more different, i'm sure it can be made to work, but its not as easy as the S5

 

so with using s5 Na components, it’ll be better to get a s5 turbo harness?

 

i still don't really understand what you are trying to do, the harness is different on the ecu/chassis end. its really hard to put an S5 harness into an S4 car.

if you're asking S5 car S5 harness, it doesn't matter much which S5 harness, they are only different by 2 wires