Is there a way to tell the difference between an S4 and S5 TB? I have a stripped/bare bones TB-----no TPS, no thermowax and want to know if it is S4 or S5?

Thanks

 

Turbo or not?

 

Na

 

The BAC on an S4 is on the driver's side of the throttle body, but on an S5 it is located on the passenger side.

 

turbo or NA is pretty easy, the NA's have an idle speed adjuster screw, and the turbo just has the casting for it, but no screw.

s4 vs s5 is a little trickier. the S4 will have 2 bolt holes to attach the TPS, the S5 has a 3rd one on the bottom. also the S5 will have 2 TPS cams and the S4 will have one and a metering pump lever.

 

if you take a hammer to both they both look the same.

 

Not sure what you mean here. The BACV is on the middle intake.

 

thanks!

 

Not sure what you think the BAC is, but it's bolted to the throttle body. The FSM verifies this.

 

Sorry, not on a NA S5 intake. It is located on the middle intake. See the emissions FSM page F1 41.

 

I stated that the BAC on an S4 is bolted to the throttle body on the driver's side. I also said the S5 BAC was on the passenger side. Where it is on the passenger side is of no relevance for if you had an S4 throttle body off an NA then it's bolted to the throttle body on the driver's side. If this doesn't jive w/your throttle body then it must be an S5.

 

the BAC is bolted to the upper plenum driver side on series 4 and to the mid plenum on the passenger side on the series 5, neither are bolted to the throttle body so it helps in neither case to verify the throttle body series.

the longer primary throttle shaft and 2 cam lobes for the TPS is the easiest way to tell.