Over the weekend I installed a vac/pressure gauge, I find these handy to help keep out of boost traveling uphill and for general awareness/diagnostics. I have one on my 3.3v6 Nissan supercharged and the amount of boost made does not vary between 0-1000 ft above sea level (what I typically travel at).

Prior to installing I was trying to get a feel for the amount of boost I should see, a pulley website claims it makes 13.1psi stock. Can anyone confirm this? I get a maximum of 20inHg while in vacuum and 10psi in boost, it does start to climb past ten with higher rpm, but I haven't ran it out to see how far it goes. Ambient air temp was 74*F, typically I see ~1psi more in the Nissan in the cooler months.

Why buy a supercharged and worry about being in boost? It's designed for it. arguably your could be stressing the engine in other ways by holding it out of boost.

I don't know what it should boost at, that will very much vary on the demand planced on the engine at any time. Also can't really compare boost versus another engine either. Both will be designed and tuned differently.

I'd much rather monitor engine temp, exhaust gas temp accurately and coolant temp as well. They'll tell you whether the engine can take the hill, not boost alone. V8 or else ...

Typically engines don't like low rpm and high vac/pressure. This is one of the highest loads you can put on a piston engine. Me keeping the car out of boost while maintaining a higher rpm is my way of taking it easy on the engine on the hills w/ one gauge vice 3.

I noticed a vac leak this morning at the gauge, not sure if it was there since install or not. Now I get a little closer to 20inHg at idle w/o AC. So long as I didn't start with any vac leaks I can use this gauge to monitor for small leaks as the hoses age and any boost bleeding that could indicate other problems.