supercharger case


Registered User
first i would like to know what an evtm book is. next thing i just pulled my supercharger off to repair coupler and decided to pull rotors from case to clean and just have a look. there where rotor scratches in the case that i could feel with my fingers. is this acceptable or do i need a rebuild. rotors look good just a lot of black gunk that should clean up.


SCCoA Member
EVTM is Electrical/Vacuum Troubleshooting Manual. Its the supplement to the main service/repair Ford manual.
Goes into more detail as far as testing/diagnosis/operating theory of electrical & vacuum issue's as well as wiring schematic's
& vacuum diagrams & component location's, grounds, feed's etc. I find it's really useful as far as A.B.S, A.R.C.
& Engine controls/sensors specific to the S/C's & XR-7's that you won't find in generic manuals. I think the main
manual makes references to it & it makes references to the main one. They kinda work together.

As far as your supercharger question's I leave that to others on here that may know.


Registered User
The EVTM for a 1990, as an example can be found on eBay, usually, sometimes bundled with the factory manual. Both are a must if you own an SC: 1990 Ford Thunderbird Mercury Cougar Electrical EVTM Manual Factory original - be sure to get the one for your year SC.

About the supercharger, since you've already broken it down you may want to consider options before putting it back on the car.

What year is your SC? The go-to-guy for questions/service on our superchargers is Charles Warner

Charles can help you determine next steps.

Good luck.


Registered User
Early, AFAIK.

Meaning that if you so cho$e, you can move to the better flowing later model. Again, Charles can help explain so you can decide. I believe he can wave his magic porting wand over an early case, but that still requires an investment.

Any photos of the scratches you found? Are they where the rotor ends meet the case?