Hi, I'm looking for a good write up on the S4 to s5 uim conversion. I have everything I need: rpm switch, the manifold, new gasket because I ripped the old one, air pump to actuate the vdi, etc. I was just hoping to find some pictures of the areas I need to grind before I start hacking away at my engine and mess it up. It's very difficult to find info on the swap save for a few old threads that have links to writeups that haven't been on the Internet since 2008.

 

if you're just wondering what to grind its pretty straightforward.
i don't have a good picture, but on the top of the rear iron the S4 and older engines have a cover plate and two bolt holes. for the old top mount starter.
the S5 and newer engines only have the one hole, because the S5 intake takes that space.

its been ~20 years but i ground a little of the iron and a little on the intake, and it fits. you don't need to grind that much

 

Will an msd rpm switch work? I just got it and saw it's only set up for 4, 6, or 8 cyls. Do I just wire it up to the leading coils and set the rpms lower than usual. I read set up as a 4 cyl to just divide the rpm I want by 1.33 and it'll trigger at the correct rpm.

 

if it was me i would hook it up to the test connector by the trailing coil, and then its just a 4cyl signal. its a bullet style connector
once you get it up and running, it helps to play with the RPM's the ports open