MoTeC Global Forum

Hi

I have the 1.05 bar pressure sensor connected to an M130 on GPA on a normally aspirated V6 on individual throttle bodies with a throttle position sensor. The engine has two separate air boxes, one per bank.

Where is the best place to attach the pressure sensor? I have assumed just ambient but did thought about connecting it to both air boxes via a link pipe.

Thanks in advance.

What are you trying to measure? Airbox pressure or Manifold Pressure? Manifold Pressure needs to be measured below the throttles. With ITB's, you need to have small tubes below each throttle all connected together typically to a small manifold to which you attach the MAP sensor.

Assuming this is an NA race engine without an IAC valve, A/C, etc, then I'd probably recommend using it as a Baro/ambient pressure sensor, or better yet, airbox pressure. Airbox pressure will take into account not only changes in altitude but any restrictions from the air inlet system and airbox. Using the MAP signal for anything load related won't do you much good on an ITB engine.

The GPA/GPR firmware doesn't really allow you to set the Efficiency/Ignition/Lambda Target table to use TPS as the load axis (which you'll need to do for ITBs) while still keeping a MAP sensor for manifold pressure reference/compensation, so you could set Manifold Estimate 0-100kPa to match 0-100% TPS and then set "Inlet Manifold Pressure Estimate Mode" to "Ambient Pressure Relative" and then install that sensor to atmosphere or to post-filter airbox pressure.

Thanks all

I was just going to use it for barometric pressure compensation, just wondered if there was a better way to use it.

With the cams this will be running I don't think using it for true "MAP" will give a good enough idle.

Looking at the TPS setup document recently, using it for airbox pressure seemed to be a step up from basic barometric.