SPOautos

We need to figure out why there is a difference between the PFC boost readings and everyones boost gauge

Where is the PFC getting its info from?

Thanks,

newRX7fan

iTrader: (1)

It uses the stock MAP sensor, which goes to a vac. hose which is sort of in the middle of the extension manifold and underneath it. I haven't looked where it actually opens into the extension manifold. It is some distance from the boost gauge tap though.

SPOautos

I kind figured that.....I think the reason the MAP sensor is getting lower boost readings is because its farther from the source (intake manifold) than our normal boost gauges. This distance could cause pressure drop that would result is lower readings.

Anyone agree with this????

Later,

atihun

It should not matter between the two, especially the distance is not great enough. Plus there is nothing between these two points to cause any interference. If this was the case, Im sure Mazda would have picked the more accurate location, especially since they actually put a nipple there and capped it of.

Anyone willing to test this?? By attaching the MAP sensor in the location of the boost gauge, and attaching the boost gauge to the MAP sensor location, and taking a drive, NOT AT FULL THROTLE but with some boost to see if the differences are also reversed?????????????

I dont think I can volunteer. My wife is not ready yet to buy me my new engine and turbo she owes me.

r71

iTrader: (3)

I have my boost gauge coming from the same line as the map sensor. I still get a different reading.

SPOautos

Holy ****, how did you find this thread...its over 18 months old haha

You must have been doing a little searching haha

STEPHEN

cewrx7r1

iTrader: (2)

It is obvious that readers have not been reading my post about proving/disproving these theories.

Facts: PFC reads map sensor voltage correctly, but it has bad mathematics when converting to ABS pressure values and to boost pressure.

Go read my first two post on:

https://www.rx7club.com/forum/showth...hreadid=154640