I know this has probably been answered a million times but couldnt find the answers i was looking for..

So my local pick-n-steal has an s5 and i am considering getting the intake manifolds if i can at a good price and having them ported. My question is will they swap right on no problems or crazy modifications? i know the auxilary ports function differently... and also what would be a fair out the door price to pay for them?

 

Ya you will have to grind alittle off the rear iron in order for the intake to sit right. And while you there, make or buy an egr block off plate. It also is in the way of intake. You also need to swap front covers being that s5 had elec omp. Unless you premix. Which is always a good idea if you plan on abusing the motor. Bac is on the complete other side of engine also. It's a trick operation but worth it if you do it right.

 

sounds like a bit of work and know-how, in your opinion would porting and polishing my current s4 intakes be a better idea?

 

Maybe with throttle resonse. Not to sure though.

 

Guide: http://homepage.mac.com/carldavis/intake.html.

How to activate the VDI (and aux. ports if your S4 backpressure method isn't working): https://www.rx7club.com/2nd-generation-specific-1986-1992-17/activating-aux-ports-vdi-rpm-switches-907824/.

The S5 intake manifold is a much better design than the S4. It's both longer and shorter. If you port out the S4 manifold, you'll sacrifice some low to mid-range torque to gain a little top-end.

There's no reason to switch front covers. An S4 would not be able to run an S5 electric metering pump anyhow. The S4 TB gets bolted to the S5 UIM, and the rod for the MOP gets bent to clear the wider manifold.