Like the title says, I'm doing a jspec swap into the Rx7. It's an S5 GTU. I know how to tell the differences between S4/5 N/A engines, but jspec turbos I'm still not 100% on.

I'm looking at engines online, and I know S5s had the electric OMP, jspec turbos included.

The two white plugs on the alternator bracket for the electric OMP, is that present on S5 Jspecs? Anyone have any other ways I can tell through photos whether a jspec 13bt is S4 or S5?

 

Easiest way to me is the thermostat housing. The S4 has the aluminum one with a radiator cap. S5 has the plastic/resin one same as the n/a cars.

 

That's true for jspec S4 and s5's? That's been one way I tell usdm motors apart, but I wasn't sure if that applies to jspec S4 or S5's

 

S5 cooling fan has 10 blades and s4 has 8.

 

See if it lists what ecu it comes with. Or from pics if you can see the sticker on the BAC Valve on the side of the upper intake manifold. The N3XX number.

 

the JDM and US engines are basically the same.