Stock Map Sensor

[catlin987987]

How many bars is the stock map sensor?

[AnotherNeon]

2.5 bar

[master_1011]

Isn't is only a 2.25??

[catlin987987]

found it on another forum. 2.25
thanks though

[catlin987987]

In Vacuum I get -16 to -20 Inches of mercury
and have seen down to -22ish

so say 10 psi reading in vacuum.
at I've seen up to 21.5ish psi in boost
thats 30 some psi each way.

I am I maxing it out?
how much is boost and vacuum.

[master_1011]

Quote: Originally Posted by catlin987987

In Vacuum I get -16 to -20 Inches of mercury
and have seen down to -22ish

so say 10 psi reading in vacuum.
at I've seen up to 21.5ish psi in boost
thats 30 some psi each way.

I am I maxing it out?
how much is boost and vacuum.

I have no idea what your saying here....

But the stock MAP only reads up to 17.5 psi...so anything above that and you'll pull timing.....

[catlin987987]

I have tuned sct
2.25 bar= 33 psi
how much of what it can read is boost and how much is vacuum?

[master_1011]

17.5 psi boost....

17.64 if you want to get technical.

[catlin987987]

how do I get 21 psi on my aeroforce gauge?

[master_1011]

Spike, probably.

The stock PCM only reads 17.5 psi off the stock MAP. Anything above that, it will pull timing. That doesn't mean you can't or won't spike higher then that.

Also, you say you have a tuned sct. I have no idea what parameters the sct messes with on the PCM, so you might have better luck in the SCT tuning sections.

[Nosfurato]

Quote: Originally Posted by master_1011

17.5 psi boost....

17.64 if you want to get technical.

Actually, 2.25 is 18.375 lbs..

Sorry man, couldn't resist

Stay at, or under 18.. and you should be fine. As long as you can get an accurate reading off the map sensor that is.

The stock gauges,.. can be well.. "funky" as everyone knows.. and even if it where dead nutz accurate.. it would still be hard to determine whether or not you are close to 18.. or a little too high with a mechanical gauge.

Even when I had my car set dead nutz on 18 lbs (scangauge) it was vary slightly from day to day.. 17.9-18.1 .. so, I don't recommend shooting for the magic 18.375 mark.. 17 should keep you safe.

[Nosfurato]

Quote: Originally Posted by catlin987987

how do I get 21 psi on my aeroforce gauge?

With a stock map sensor.. you wont see that high. You can buy an external 3 bar map sensor from Aeroforce, that will plug into one of the analog inputs on the gauge.. that way.. you can get an accurate reading.

[Nosfurato]

Quote: Originally Posted by catlin987987

I have tuned sct
2.25 bar= 33 psi
how much of what it can read is boost and how much is vacuum?

Well, you have to consider that 1 bar (normal ambient pressure at sea level) is 14.7 psi. So, right off the bat,.. as far as boost numbers go.. you take that out of the math. So, thats leaves you with 1.25 bar (above ambient pressure) so, take 1.25 * 14.7 and you get 18.375.

Now, as far as how much vac it can sense?? Im not sure what the max range is. Or even how it senses it for that matter. I don't believe its taken from the map sensor.. given the fact , even if you take that 33 psi window 2.25 * 14.7 that would still only leave a "theoretical" 14.625 window for vacuum sourcing .. (call it 14.7) .. I know that it will display lower than that on a scangauge.. so, exactly how, and where its getting its vac reading? I dunno.. I am actually looking into that right now.

Will.

edit : Couldn't find any info.. so.. The only thing I can figure, is that the MAP sensor can read.. who knows on the vacuum side.. maybe all the way to -100 . But, the 2.25 spec comes from (including sea level) and above. So, I'm not sure how "low" it will read.. but, this is the only thing I can come up with that makes any sense to me.

[AnotherNeon]

i thought it was a 2.5 bar oh well

[Nosfurato]

Quote: Originally Posted by AnotherNeon

i thought it was a 2.5 bar oh well

It IS a 2.25 bar sensor.