For those of you with fuel pressure gauges, what's the highest pressure you've seen? I know stock at idle is supposed to be something like 42-45 psi, but has anyone seen any spikes? I am trying to decide on whether to get a 60 or 100 psi gauge to mount on the fuel rail, since I am going with a aftermarket FPR.

 

it will be relative to your boost.

Base should actually be lower than 42 at idle - more like the mid 30's. At 0 vacuum, it should jump to 42-45 ish, then increase 1:1 with bosot, so at 19 psi, you should see a steady 61 psi of fuel pressure, for example.

 

If you are installing a mechanical gauge right onto the rail then you only need up to 50 since it can only be used to set base pressure unless you want to stand there and watch it hit ~65 psi while a full tilt on the dyno. FWIW, most seem to put a 100 psi gauge on.

Mark
www.Quantum-Racing.com

 

Your right, I should have been more specific. Manual states at curb idle under vacuum, pressure should be 33. With vacuum hose disconnected(0 boost), should be 42-45 at idle.