S4-on-your-back-door

Hi fellow 928 lovers, Im a newbie to rennlist so please bear with me on my learning curve. Im supercharging a 87s4 auto and am not sure were my fmu should tie in at. I bought a mustang setup, 30lb red tops and a 12:1 fmu also have installed a rising fuel reg. from 928 int. and set my fuel pressure to 28~30lb at idle. My questions are as follows 1 were do i tie in FMU diagram would be nice. 2 how much can u boost an 87s4 before blowing head gasket.
pls give boost lbs with the appropriate pulley dia. with and with out intercooler.
THKS, and yes the timing belt and waterpump/tensioner have been replaced

MarkRobinson

You need to recalibrate your FMU to 6:1 roughly with 30# injectors first off. Replace all your under-hood rubber 20-year old fuel lines before you boost your shark: otherwise you're very high risk for engine fires. At the back of the engine, there is a fuel damper on the driver's side & a fuel pressure reg. on the passenger's side. The center outlet of that should go into the FMU, & the oulet of the FMU should return back to the barb that goes into the fuel cooler mounted on your fire wall. S4's can take about 8psi before your starting to push your luck on factory head gaskets, 10psi or so with proper timing retard: do your homework by researching threads.

FeedNfrenZ

If you can see this this is how mine is set up.
Pink= dampners
Blue= regulator(left image is stock setup with fixed reg. right is adjustable reg.)
Teal= FMU
Dark green= fuel cooler on fire wall
Green= fuel rails

Lower image is from Tony on twin screw thread.