wrighty338

iTrader: (33)

whats a 3 bar map sensor and the benefits of it?

also is a 3 port boost solenoid essential for boost control?

STI_Baly

iTrader: (23)

Well i'll give it a go.....i believe the 3 bar allows you to run more boost basically. thinking again now, its something to do with the voltage maxing out on the standard therefore the larger 3 bar is brought in to run more than stock boost.

The 3 port solenoid is a better solenoid basically, allows you to run more controlled boost. Although i have yet to hear of anyone say the 2 port is not up to the job, depending on your boost goals obviously.

Sure the pros will give you the tech on it all if needed.

But i do know that in order to make the most of the map sensor you will possibly have to go for a remap. I run a 2.5 Marrelli type map sensor.

Good Luck

joz8968

iTrader: (13)

If you were to replace you existing OEM MAP sensor with it, then it allows the ECU to 'see' 3bar (44psi) of pressure in the boost control system... so you can run anything fom 0 (lol) to 3bar (not a good idea lol) worth of boost pressure before a fuel cut, should your engine/mods/map allow/be suitable for.

bluenose172

iTrader: (2)

The 3-Port allows for finer boost control and gives you a wee bit more headroom with your WGDC's.

MartynJ

A 3 bar map sensor wil not allow it to see 44psi of boost , that would be a 4 bar as a map sensor needs to read below atmospheric too...
1 bar down 2 up = 3 bar..

Daveysaff

As said, a 3 bar will see 29/29 psi.

Do std big turbo escort cossie map sensors work btw? they're marelli 2.5 bar.

172sport

iTrader: (6)

As above, you need to remember we are already at 1 atmosphere.

3bar will be ok up to a ballpark 2bar boost

joz8968

iTrader: (13)

Ah, terribly sorry Martyn... (I must not dish out out 'advice' that I'm not totally sure of )

So MAP sensors are rated at 'absolute pressure', not 'relative pressure', right? So, as has been said, and in this case, it is already taking into account the 14.57psi (1bar) natural ambient air pressure, before 'adding' it's own 29.14psi (2bar) allowance 'on top'... so to speak?

Shaun

That is why is is called a MAP sensor.... Manifold Absolute Pressure.

Of course we could get really technical and explain that a single atmosphere is not always 1bar, as it depends on the atmospheric conditions. Get up Mount Everest and measure the atmosphere at the top of that. Yeah... best not go there!

Wrighty338,
Using a MAP sensor instead of the traditional MAF sensor is a very different principal. They would require a different ECU (in most cases). Simplistically, a MAP based system can get over some of the "issues" around the frailtys and limits of a MAF based system. This can range from dodgy MAF sensors fubaring and limits on scalability for certain power levels etc.

A 3 port boost solenoid controls the pressure to the actuator, which determines how your boost is controlled. A 2 port solenoid has an input and output (pass through). A 3 port solenoid has an extra port, to enable pressure to bleed off when required. In theory this should provide better, faster boost control.

joz8968

iTrader: (13)

Doh, of course... of course

wrighty338

iTrader: (33)

sooo, could i get rid of my maf running an apexi pfc or not. i think mines the L -jetro

would you advise a map sensor or can i not run one with a maf?

where can i get a 3 port?

wrighty338

iTrader: (33)

maf shouldnt be restrictive under 400bhp though im sure...

joz8968

iTrader: (13)

If you have only got the L-Jetro version of PFC, is there any way it can be made to read from the MAP instead of MAF?

I've heard murmerings of something called Mafsim? What is this? How does it work, etc, etc?

EDIT: Ha. It looks like SN has finally sorted it's clock out - it has been put back one hour for the correct time - hence this post ending up BEFORE Matyn's below. Had anyone else noticed that their posts had been exactly an hour 'late' lol?

MartynJ

Not on the L-Jetro to the best of my knowledge , the D-Jetro is MAP based..

Jolly Green Monster

iTrader: (4)

there is no D Jetro for the Subaru..

there is/was a way to convert the Ljet to use map call the mafsim but not really available anymore..

can you explain what you are trying to achieve?

if you want/need to go map based then you need a different ecu.

the 3port boost solenoid controls the boost more effectively than the standard 2port setup.

the PowerFC has the option of the boost control kit which comes with a 3bar map sensor.. but the boost contorl for running that high boost is not as nice / good as an electronic boost controller like the Apexi AVC-R for example so if you are running a setup that will take that higher levelr of boost then you would do best to go for that..

The standard 97 on map sensor is a 2.5bar..

Simon

joz8968

iTrader: (13)

I was just wondering if the PFC was capable of running MAFless with mafsim? What DID mafsim do? Presumably it emulated the MAF's air density measurement/voltage WITHOUT actually using a MAF, no? If so, what actually was it - some piece of electronic hardware or something? I'm confused?


Is that 2.5bar absolute... therefore 1.5bar relative?

STI_Baly

iTrader: (23)

They sure do, I have one fitted

Daveysaff

That'll be handy when I buy an Impreza then, i've got 3 in the garage!!

Jolly Green Monster

iTrader: (4)

Yes and Yes

but the 97 on map sensor doesn't work very well with earlier than 97 powerfc

joz8968

iTrader: (13)

This Mafsim sounds good! How come it's not available anymore?! Or is it just elusive i.e. could I actually get hold of it if I really tried lol? How much would it cost? Where would I get it? What does it look like, etc?


Would a Bosch or Denso aftermarket one work better? Or the Cossie one as mentioned above?... It's okay though, as I've got the Boost Control Kit waiting to be fitted at a later date, anyway.

Jolly Green Monster

iTrader: (4)

the maf sim is no longer an option..

no use the apexi boost control kit map sensor or a boost controller..
you can't rescale the map sensor on the apexi so you are stuck with standard or apexi's own..

Simon

joz8968

iTrader: (13)

That's a real shame, though


Yes, I'll use the PFC BCK ... FTR, what's its MAP rated at - 3bar absolute (2bar relative)?


Thanks Simon - as always, a mine of knowledge all things Subaru

Jolly Green Monster

iTrader: (4)

it is a 3bar sensor yes..