Tech Question on Boost Reading
 

I just Purchased a Ark Design Digital Unit. I am having some issues with the boost reading. Does anyone know where I would pick up boost reading?? It's connected to the MAF sensor, reading vaccuum and not getting any boost reading. The car does not have a boost controller.

Ok I don't know what you mean by it being connected to the Maf sensor? I am assuming that they did it like the directions said and there is a vaccuum line on the pipe that goes into your intake manifold. You can T it there and you should get a positive reading. Remember while ideling you are going to get a vacuum. In order to see if the guage is working properly you have to go drive the car. Just go down the street and romp it a little over 3k and you will see about 2 psi on that guage if you got it right. Just reving the engine wont show the boost as the turbos need the exhaust load to spool them up.
Frank

I would assume to get a reading right off the maf you would need a 2 bar.

I don't see how you can get a boost reading right off the maf sensor it self. Frank

maf = mass air flow meter

map = manifold absolute pressure

and you would get the reading from neither, get it from a vacuum port on the manifold.

and nobody on here would probably need a 2 bar sensor as nobody is running over 14.7 psi.

^ Bullitt might be actually. I think they lowered compression, he might be running 30psi for all we know.

haha ok i correct my statement... rcz dont need a 2 bar sensor :icon23:

there is software out there :D

ok a few things need to be straightened out here, i looked up the manufactures website for info and it reads information through the OBD2 connector, for boost on our cars you are going to need to buy the "boost sensor"(what they call it, not me) and hook that up to the manifold.

Next, Map sensors are manifold ABSOLUTE pressure sensors, meaning they read and are rated from vacuum. a 1 bar reads up to 15psi absolute meaning a hair over atmospheric(this is the factory unit on the 370), a 2 bar reads up to about 15-16 psi boost making this the most common aftermarket sensor, a 3 bar reads to something over 30, and the hardly ever used 4bar is for bullitt because it will go up to like 46, all the map sensors i've ever bought have been rated like this. read the spec sheet on any ecu or ignition box with a built in sensor they usually say 2bar maximum 15psi

Oh and Jmac88 is right about the software they take the MAF reading and the rpm and back convert using the displacement and VE to calculate estimated boost of course if your VE is off or the particular program doesn't account for it it can be way off.

You need a boost sensor! The end!

Edit: Tap the boost line into the back of the intake manifold and then into the boost sensor and then electrical wire into the digital unit. From what I have heard, tapping into the back of the manifold gives very accurate boost feed back.