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Cobb AP Boost Gauge Reading

Hijinx

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#1
I'm about to drop a nooby question on ya'll...maybe it'lll enlighten some others as well though.

It was brought to my attention that the Cobb AP boost gauge (probably) only reads in PSI. What this means is that the vacuum you're seeing is in PSI, and not in/HG. Until my big turbo upgrade I always assumed that our cars just had weak vacuum. Since I'm running a GTX, I'm using a Tial Q and this is where the question came from. If the Cobb AP is indeed reading on in PSI this means one has to convert PSI to in/HG in order to find their true vacuum. With that number one would choose the correct spring/setting for their BOV... Now, since our cars are MAP/Speed Density tuned, it's not a HUGE deal, but I'd still like to have this confirmed/debunked.

Maybe one of you with extensive knowledge can chime in? @ian@cobb [MENTION=688]Sourskittle[/MENTION] [MENTION=3178]maperformance[/MENTION] [MENTION=1098]drag4life723[/MENTION] [MENTION=930]dyn085[/MENTION] or anyone else that knows.
 


dyn085

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#2
Yes, your only option is to convert. Boost is only read out in psi or bar.
 


DHM1

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#3
8-10psi BOV spring will work good on our cars. You said its open at idle which it should be. Also who ever sold you the BOV should know before they sold it to you.

Russ
 


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#4
PSI and inHg are just different units for the same measurement. For example, if I measure something in foot or millimeters, the length of the item is the same either way. Currently, we don't have a function in the AP to convert a measurement at a certain threshold, but you could always apply the conversion to an entire row in a datalog to see it in different units.

Ian
 


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Hijinx

Hijinx

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Thread Starter #5
8-10psi BOV spring will work good on our cars. You said its open at idle which it should be. Also who ever sold you the BOV should know before they sold it to you.

Russ
I was given the black spring (6psi) to run instead of the plain spring (10psi) that was already in the unit. :\
 




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