I've searched, but can't really find anything that will help me out.

I bought a 91 Vert with a turbo swap that was about 85% complete about 2 years ago. Just needs a clutch and an ECU. Had a daughter, bought a house, etc so life got in the way. Finally I pulled the cover off the car last week and got back to working on it. Right I am trying to shop for a clutch but every site I do needs to know if it is a s4 or an s5. What are the tell tale signs to determine the difference?

Here are pics of my motor, if it helps: https://www.rx7club.com/2nd-generati.../#post10083095

 

shop somewhere else / s4 and s5 turbos run the same clutch .. the only difference is the original s4 turbo clutch was 5mm larger diameter than the turbo s5 units ..( 245 mm v 240 mm ) they are intended to retrofit each other

motor wise// then you cant have searched too hard.. there must be several thousand posts on how to spot s5 engines from s4 ones

the s5 has a slope on the banana on the inlet manifold ...a dimple on the front runner for the corner of the IC which has a larger induction pipe and better core , knock sensor threads above trailing plug, steel fuel rails , twin TPS and 3bolt thermoneck top would be starters .. so would reading the number on the ecu case

 

There should also be serial number on the side of the engine. Not much information but it could be a lead in addition to bumpstarts' reply. Correct me if I am wrong..

 

going by the pics in the link it is an s5T block.. again all FC turbos use the same interchanging replacement clutches,, known as the 9.5 incher

 

Confirming it appears to be s5 from the water neck and knock sensor location. The clutches are interchangeable.

 

thank you