I installed an OBA on my 99. Before the OBA i could see 21-22 psi! After on my "EDGE" display i only get 14-15 psi. Is my "EDGE" reading what is going to the map sensor? If i had a manual boost gauge would i see the samething or the hopefully higher but correct boost? THnaks

 

Is the Edge tied into a wire going to the MAP sensor? My guess is yes, so the Edge is only going to read whatever your OBA lets it see. A real boost gauge with a probe will give you an accurate reading.

 

If it plugs into the OBDII port then yes, it just showing what the PCM sees from the MAP sensor. If it is only showing 14-15psi though you need to bump up your OBA, you should see 19-20psi in your case.

 

If you install a "a manual" boost guage make sure you tie into the "line" side of the OBA and not the "load" side. The line side is actualy boost, the load side is what is limited by the OBA

 

So i what kind of boost will i see with the oba? And thanks for info. Looks like i need a real boost gauge instead of the phony edge set-up

 

You should see what you were seeing before 20-22 psi maybe more if you didn't have the edge. The Edge does a good job of reading the boost from your map sensor. IF you are limiting the pressure,boost, that the map sees then the edge will only read that.

 

Jim i meant to ask if i would see more boost total with the OBA? Not what the edge is showing.

 

All the OBA does is hide the real boost from the PCM so it doesn't defuel the engine and set the CEL. The only way it would help with making more boost if is you had the fuel & turbo to make it in the first place, then yes, it would help. Otherwise all it does is keep the PCM dumb & happy. LOL

 

Thanks for great info! Does it make a difference if the oba is set at 15 or 20 psi?

 

22-23 psi would be best. Just below the defuel point. I have mine set at 23 psi and it doesn't defuel or set the SES light.

 

If you do go with a boost gauge, most people are using the AIH delete plug with boost port on the intake spider. You can get this from Riffraff Performance. you don't have to worry about the line going to the MAP sensor when using this. You can monitor both the actual boost and the OBA "set" point.

 

I read through half this thread trying to figure out what On Board Air had to do with a boost gauge and why on earth you would hook a boost gauge to it. Funny thing is I have an OverBoost Anhilator. It's one of those days.

 

LOL Not laughing at you, but with you!
IIRC at anything above 20psi and the computer is feeding all the fuel it can to the injectors. Set your OBA to 22 PSI and you'll get all the fuel you can get w/o the SES light from overboost.