boost gauge question
 

apart from appearences, what is there a difference be an expensive name brand boost gauge(autometer) and a cheaper one(auto gauge)?

Autometer is not an expensive gauge. At least not the mechanical ones, they ALL have the needle move away from the zero after time, i have seen ones up to 3psi away.

Defi, GReddy, SPA Design. All quality, Autometer not so much.

The chinese stuff is copied so well, there isnt much difference. Until you get into non mechanical gauges, where basically everybody is good.

my autometer srt4 boost gauge reads 5 psi as 0 psi.

Exactly.

The mechanical gauges, as explained, are terribly inaccurate. But that's not what makes them useful. You watch them for trends, not for exact values. IE if you normally idle at xx vacuum, and the car starts to run like shit and your gauge shows less than xx vacuum, you know you have a vac leak. Or if you're used to seeing YY PSI boost at WOT, and you see way more or way less, you know you have a problem, etc.

If you want accuracy, get an electronic gauge. Or an EBC with a gauge display.

My StewartWarner reads about -1" at 0psi.
But when I dyno'd it, the gauge never got above about 13psi and the dyno was reading near 18psi.

Thats weird. I was always told that mechanical gauges reads more accurate then electronical gauges. Uh. Guess I was told wronge. Or maybe I heard wrong. Either way I'm dumb ass. Sorry......I'm gonna go shoot myself now.

you can adjust the srt gauge to read right.

never seen an autometer that read 0 at 0 psi. look at them at any store.

never seen an adjustment on one either.

i suspect it's the internal damping preventing it from reaching 0 and that the fluid damped ones are better but i'm not positive.

everytime i adjust my needle to read 0 (reads 2psi when shut off) it end back up in the same spot after a few days.

lmao braineack its funny you say that because i did the same shit the other day. It was pissing the hell outta me so i ripped the glass off the gauge and adjust the needle where i wanted it. 2 seconds later it was back to 2 psi on shut off. I really want the AEM electronic boost gauge cuz i think it would match my aem uego wideband that i just bought

:dunno: mine stays right at 0 when off maybe you guys got knock off gauges or something. Mine has been reliable and accurate for me throughoutt he use never sticking etc. And it is i autometer paid 30 bucks for it hpe it lasts awhile.

The autometer can be adjusted... Pull the light and adjust with a small screwdriver the spring( don't know what its called)

How do you know it's accurate? Just cuz it reports 0 vac when you turn the car off, doesn't mean the gauge is actually accurate.

If you want accurate, get a MAP sensor. If you need to know ballpark, condition of tune, trends, etc, the mechanical gauge is perfect.

mine reads +1 psi when off... close enough for a sub $50K car :)

+1, since i used to have an EBC with a map sensor, i know when my gauge reads 10psi, im acutally at 6.5psi

mine was pretty close but I would just read the data logs off my Link, or look at the gauge on my EBC anyway.

so what you're all saying is it doesnt matter what kind of mech. boost gauge i get... cheap or expensive they will tell me waht i want to know which relative boost.

yep

scaling and zeroing are different things. I'm curious what you'd see if you put a vac pump on it and checked the calibration. zero is pretty unimportant compared to peak boost if engine life is your concern.