I have looked through the archives and ran a search, but still can't find what I am looking for. I am getting ready to put a S5 engine in my S4 chassis and am planning on getting rid of all non-essential emissions stuff. Is there somewhere that details what can be removed, what needs to be plugged, and what needs to be hooked back up on the car?

 

The S5 emissions control the VDI functionality and 5th 6th ports which all this is controlled by the S5 ECU. Not to mention non of your sensors from the S5 will be compatible with the S4. If you are planning on putting the S5 engine into your S4, you basically can only use the bare block. Anything electrical must come from the S4.

You probably will want to figure out if you can use the S4 lower intake manifold on the S5 block. I know they will bolt up, but the intake ports for the lower manifold MAY be bigger from the S5 block, so a small amount of porting may have to be done to your S4 lower intake manifold. Once you can get the lower intake manifold onto the S5 block, everything will be a breeze. Make sure you can keep your auxiliary ports functional with the exhaust pickup tube from the S4.

Then there is the issue with the oil metering pump. S5 is electronic while s4 is mechanical. You will have to switch out the front cover from the S4 into the S5 with the S4 OMP on the S5 block. Otherwise run premix with block off plates.

Check out rotary resurrection if you still have questions...

 

If you remove your air pump you'll need another belt to drive the waterpump. Either a yoohoo belt or 2nd alternator belt and pulley. The air pump belt is the main drive for the waterpump, the alternator belt barely runs across the waterpump pulley.

 

I am planning on removing the air pump (though I did recently see a write-up about using it to run VDI and 5/6p). I want to keep cruise, A/C, and power steering while getting rid of all stuff not essential to those systems and the engine itself. I want to simplify the engine bay. I know about having to use the S4 sensors in the S5 engine and am planning on using the S5 intake manifold and S4 TB. I just want to know what can be removed from the system.

 

I have removed my air pump and havent added any other belts at all. My water pump works just fine..
89 FC NA

 

I was thinking about running an aquarium or similar pump to control my 5/6 port actuators and VDI, but I'm starting to think about just leaving the air pump on the car and using the small outlet to pressurize those lines along with the spider going to the oil injectors. Then, I could just cap off the larger outlet and not have to worry about a electric pump. Any thoughts?

 

https://www.rx7club.com/2nd-gen-archive-72/emissions-equipment-what-you-can-remove-how-112251/

/thread

 

Not trying to steal your thread, but On a S4 NA, when removing the emmisions, is it possible to just get rid of the hardlines and keek the pressure regulator and egr? after reading that link, it seems there is no real reason to removing the pressure regulator or egr.