Ok, so I have a S5 JDM TII going into my S4 N/A. I was originally going to do everything S5 and just splice the EM and Dash harnesses into the S5 ECU. However, I got my engine and there was an S4 JDM Turbo (N340) ECU with it which got me thinking that it might just be easiest to find a couple parts and use my S4 N/A harness. I have been searching through all of the information on these swaps for weeks and there are a lot of different opinions and so much information across the forums, so I will just state what I know and feel free to comment. Also, I am looking for what I NEED, not just what is recommended (although please state that too)

So here is what I think I need to do:

Take the S4 N/A Front Cover, OMP, and TB and swap it onto the S5 TII (will the N/A ones work or do I need the turbo ones?)
Use the S4 Harness and swap the couple of wires that differ
Splice the plugs from the injectors on the S5 harness onto the S4 harness (I've read that the high or low resistance doesn't matter)
Use the S4 AFM an MAP

Here are my questions:

Now what about sensors? Which ones will work from the S5 and which ones will I need to get?
Can I keep the S5 intake and exhaust manifolds?
Do I need to switch my waterpump, waterpump housing, and fan?

Please note that this is an S4 NA so if some things need to be from the S4 turbo to work, please let me know.

If there is anything you can think of that I am missing, let me know.

Thanks guys (and maybe ladies)

 

the throttle body will fit if you use the turbo manifold but you will have to port the manifold to make it flow good.

__________________

only ports that will line up will be the center ports the out side ports one the end plates on the six port are taller then the turbo manifold here is a pic my turbo mani with the six port gasket/ this will only look like this if the s5 throttl body and manifold are six port but you can sent it out to have it done or you can do it youself

 

so it sounds like it would be smarter just to get an S4 TB? do I need a TPS too?

 

That would've been a nad idea. It's just not worth the considerable effort required. There are only minor advantages to using S5 electronics (nothing performance related), but there are many differences that would need to be addressed.

Good idea.

You need to use a Turbo front cover or you'll have nowhere for the turbo oil drain.

You have to use S4 Turbo AFM and MAP sensors, not NA ones. These must match the ECU used.

Yes, and you should, they're better.

There's no need to swap them.

 

How about the boost/pressure sensor? I have an S4 N/A one and an S5 TII one. Will either of those work?

 

As in Manifold Absolute Pressure...

 

Ohhh...so the boost and MAP sensor would be the same. My bad. I think I was getting mixed up with the MAF. Thanks NZ.

 

Actually we don't have a MAF (hot-wire) sensor to get confused with.