Does the boost sensor on my '99 1.8L FD motor measure boost levels(psi)or just if there is boost or vacuum(yes/no)?
Also, I've asked this before, but the thread has seemed to have died...
I've noticed that many people running boosted Pros get a BAR-MAP(usually from an RX-7?). Why couldn't the MAP sensor be mounted before the super/turbo-charger?

 

Your meter only measures Mass flow....it doesn't know if its got a turbo or not.

A MAP sensor measures manifold absolute pressure inside the manifold, this will know if its boost or vacuum. No protege ever came with one.

The RX-7 uses a VAF which has a flapper door that in combination with an air temp sensor measures the resistance on the door as airflow. It is not a MAP sensor.

Those of us running haltechs use MAP sensors. Those running gtx/gt-r ecu's run VAFs. 95-up EGT's run MAF sensors.

 

I beg to differ Braden...the FP and FS motors do have a boost sensor or Pressure sensor mounted in teh top passengers side corner of the engine bay and the 3rd gen RX-7 had the same thign I've cross referenced P#'s and they are the same it is a Mitsubishi boost sensor that can read both vaccuum and boost. It is not used by the ECU in teh proteges though as just a cross reference between teh MAF though.

 

I've actually seen that same sensor on Miata's..... I don't believe it is for actual "Boost". Would be nice though if it had a useable output.