NB Boost sensor (Factory MAP sensor) calibration
 

Does anyone here have the NB factory map sensor calibration? I was looking at putting a MS3Pro module in the factory ECU case and the module does not come with a map sensor. I was wondering if anyone has used the factory map sensor with a megasquirt.

This would come in handy for anyone running in an autocross class where you cannot add/modify map sensors etc.

is your car n/a? cause it's just a baro sensor, it doesn't actually read boost

Yes, it will be a N/A only car. Thanks for the information too. I am in the planning stages of swapping in a VVT motor, similar to what I have in my NA Racecar. Going to be sweet to have the same 145hp, but with A/C and a radio as a daily driver!

There is no map sensor in these cars, only a MAF.

'99+ have a "Boost Sensor" mounted on the fender above where the evap canister is located.

MX-5 Miata Forum


https://www.miataturbo.net/attachmen...ine=1460152830

whaddayaknow, I stand corrected :). We don't have a boost sensor on NB's overhere, only on NBFL's. Never knew US cars had one.



https://www.miataturbo.net/attachmen...ine=1460155127

I was just getting ready to ask this same question. Anyone know the answer?
0V = X
5V = Y

@Reverant ?

The stock "boost sensor" is there as part of the EGR valve control loop.

--Ian

It will be re-purposed as a Baro correction Sensor.

I'll try and pull one off the parts NB around here and compare it to mine.

That would be kind.

However, if someone does not have the data already, I should do that work.

Figured I'd just put it on a tee with the MS and a vacuum / pressure source, plot a curve, calculate the calibration constants, and publish them. I think Thumpetto007 is going to need them as well.

Honestly, it might be a month before I get to it. So whoever gets there first.

0V - 15kPa
5V - 115kPa

really that's it? According the the manual the OE ECU uses it to adjust fuel trims in boost, so basically the ECU just knows it's in boost, but how much it doesnt care?

huh? N/A cars don't go into boost.
Unless you're talking bout the msm which also doesn't read in boost it just goes open loop and assumes urrythang is "ok"

no, the ECU uses it. On the MSM mazda even refers to is at the "BAROMETRIC PRESSURE (BARO)/MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR", and not just the BOOST sensors on the other NB2s -- but it's the identical sensor and plumbing.


https://cimg6.ibsrv.net/gimg/www.mia...2d1bc00f1b.png

There's references that it uses it for fuel trims. Looking for that now, but the ECU at least knows that car goes into boost -- what it does with that knowledge is beyond me.

Interdasting cause over the many years and years of the M-S folks looking into this, no one has ever been able to confirm that the MSM actually see's or records or references boost in any meaningful way. (as in, it actually see's the 6-8psi that it makes when in OL)

not sure. obviously the map sensor reads above atmospheric, it probably uses a combo of that plus the MAF voltage to figure things out. Doesn't the MSM even have an over-boost cut?

Overboost is set by load I believe which is maf voltage + rpm. If it's the same sensor, and the sensor reads to 115kpa only, even if it did use it I bet it would only be a CL/OL trigger. Which it's not, cause we already confirmed CL/OL is triggered by the TPS on those cars. I am open to be proven wrong, but you'll need some proof.

no you're probably right. it can basically see postive boost, but probably doesn't do much at all with it, just switches to a boosted map.

I'm going to plug in Rev's numbers. Likely within the week (schedule update) I'll have the MS at least temporarily hooked up to test spark and injector harness updates. At that time, I'll have a borrowed, hand vacuum pump and be able to compare the internal MAP values with this sensor's readings.

Note, Rev's values are quite close to the GM 1 BAR values, so if it is indeed a 1 BAR sensor, the numbers make sense.