Which of my gauges should I trust?

[TooleBox]

I have a stewart-warner mechanical boost gauge, as well as the greddy profec-b spec II...

My profec reads 7-7.5 all day long

my S-W only reads 6...

I really dont know which one to believe... they are both spot on from 0-5psi... but anything above 5 has mass variation...


any opinions?

[mspeed101]

thats strange! they should both be reading the same.

[03MSP]

Probably already thought of this, but I would check for leaks in the mechanical gauge...if none are there, I personally would trust the mechanical.

[TooleBox]

no leaks in either and both tapped off the same line source... but i KNOW im makin more than 6psi... the butt dyno doesnt lie

[KyRaceFan]

strange indeed.
Id trust the profec more than the mechanical though, as they can lose calibration and accuracy.
Have you tried another tap?

[prospeed]

i would lean on the profic to be correct. my buddy has an autometer electric with peak recall and blitz boost controller with the same and both read the same. my autometer mechanical sucked ass. when i shut off car the needle would rest in a different spot. can't be to accurate. i would get an electric one.

[TooleBox]

yeah... i think i am gonna get an electric one

[mspeed101]

i would lean on the profic to be correct. my buddy has an autometer electric with peak recall and blitz boost controller with the same and both read the same. my autometer mechanical sucked ass. when i shut off car the needle would rest in a different spot. can't be to accurate. i would get an electric one.I have to agree with you. My autometer gauge when I shut off the car would sit at 1-2psi! I switched it out though and the new one is more accurate but still may be off a little. im gonna get an electric one as soon as I get enough money together.

[prospeed]

http://www.msprotege.com/members/prospeed/gauge%20002.jpg

great gauge and its alot easier to read. supposed to be the most accurate dig. gauge.

[TooleBox]

prospeed... thats an autometer? how much did it cosy you and from where?

[prospeed]

no i replaced my autometer with this. its made by dynotune. i paid $160 for it about 2 weeks ago. the only thing it wont read 20 inches if vaccum. it read in psi scale when in vaccum so it would read 10. i got used to it real quick and its slightly bigger tha the keyless entry remote. i also have it up for sale. i am taking everything out of my car.i am probably going to trade in on something else in a few months.

[TooleBox]

i think im just gonna relocate my profec to a more visible location and ditch the mechanical gauge

[prospeed]

thats what i would do if i had the profic.

[KyRaceFan]

i think im just gonna relocate my profec to a more visible location and ditch the mechanical gauge
good idea, the profec is whats controlling the boost, so its definately the one thats right.
Id check your mechanical gauge for a pinch in the line somewhere.

[Wha'Happened]

go with the profec, I would personally. I read somewhere about a guy w/ an fdRx7 and the same problem. He went with the profec too.

[Wha'Happened]

or wait, I dont think it was a profec but it was a more "name-brand" bc.

[TooleBox]

well... i checked all the lines, all was cool... i just think the gauge is off... i went and bought an Apex-i boost gauge today... may slap it in tonight... but im hoping that it reads more accurate (especially for how much the thing cost!)...

[TooleBox]

well, i bought a high-end Apexi mechanical gauge, and now the gauge and the profec read spot-on all the way up! it was definately the stewart-warner gauge that was messed up somehow

[TooleBox]

... my setup is golden now... i appreciate all the help everyone!

[t3ase]

lame post deleted. sorry bout that.

[TooleBox]

thx