Boost Pressure by Air Temp

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Boost Pressure by Air Temp

Postby rlees85 » Sat Sep 22, 2012 11:59 pm

Just wondering, what does this map do?


BoostLim.png




According to this map, I can never request more than 2170mBar of boost when IAT is above 20c. IAT is always above 20c pretty much and PP2000 says I am requesting upto (and getting) 2212 mbar...
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Re: Boost Pressure by Air Temp

Postby RPM freak » Sun Sep 23, 2012 11:22 am

Limits the boost at certain air temp and boost.

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Re: Boost Pressure by Air Temp

Postby rlees85 » Sun Sep 23, 2012 3:13 pm

I thought so... I guess my ECU either ignores it or allows more than the max in certain conditions

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Re: Boost Pressure by Air Temp

Postby Relic » Sun Sep 23, 2012 9:16 pm

That map makes no sense.
If you are at 2000mbar whats the point of saying you can be at 2200mbar :eh:

Is it saying above 50c boost will be cut ?

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Re: Boost Pressure by Air Temp

Postby rlees85 » Mon Sep 24, 2012 10:06 am

The only thing I can think of is it stops the turbo from surging by making boost increase slowly, rather than trying to go straight from 1100mbar to 2200mbar...

The other purpose is obvious limit boost by the air temperature.

I just dont understand if my IAT is 27c why am I requesting 2212mbar of boost.... (the map clearly doesnt allow this)

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Re: Boost Pressure by Air Temp

Postby RPM freak » Mon Sep 24, 2012 11:37 am

If inlet air temp is very high then air density drops and there are less O2 molecules to be used for efficient burning of the fuel and the car starts to smoke.
For high boost applications you will need bigger intercooler.
You can rescale the X axis above 2000 millibar when you are running more boost then original.
For standard remap you will need to tweak this map.

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Re: Boost Pressure by Air Temp

Postby Relic » Mon Sep 24, 2012 12:02 pm

Ahhh I see.
This is inlet air temp at the manifold and not atmospheric air temp :roll: :lol:

But the MAF sensor reads airmass...so air temp/pressure is a mute point with a lambda map ? :?

Come to think of it IAT will be much hotter than ambient so the OP definitely shouldnt hit those targets. :eh:

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Re: Boost Pressure by Air Temp

Postby rlees85 » Mon Sep 24, 2012 12:47 pm

As far as I know the 406 has no way of reading IAT at the manifold. It has an IAT sensor built into the MAF sensor just past the airbox and that is all...

In otherwords the air temperature in this map must be air temperature at the airbox.... unless I am seriously mistaken, in which case please correct me as it would help me a lot to know the air temp at the manifold

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Re: Boost Pressure by Air Temp

Postby Relic » Mon Sep 24, 2012 5:46 pm

Well manifold temps are normally set not to exceed 130c.
Thats basically what you use when selecting Garrett turbos and using theire formulas.
Generic 85% VE and 130c.

So the fact these temps go upto 130 and air temp never reaches anything like that would make sense for an IAT sensor in the MAP sensor.
Have you tried digging up the specs for the MAP sensor ?
Bosch will often send datasheets for your vehicle if you ask real nice.... if it has a bosch map sensor.

Still....if you do only have ambient air temp sensor on the MAF...then its possible you could still hit the targets.

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Re: Boost Pressure by Air Temp

Postby Relic » Mon Sep 24, 2012 6:17 pm

http://www.tuningwizard.co.uk/index.php ... ts_id=1373

This device connects to the IAT (inlet air temp) sensor using simple easy to use connectors, the IAT sensor is normally built into the MAF sensor near the air filter on cars made after 2000, before 2000 it is usually on a seperate 2 wire plug, make sure you can locate this before buying

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