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Discussion Starter #1
Hi all,
while under boost .9bar my afr is 10,5-11 . I have bought the car in japan and live in the caribbean. I have no clue if i have a ecu that is not stock. Could it be that i have a upgraded fpr mounted. Has anyone have a pic of a stock fpr. I have a innovate afr lm1 installed and thats why i can tell the numbers on my afr.also max exhaust temp was 600 degrees cel. 10inch after the turbo.
So i guess +200 degrees to obtain manifold temp.800 celc stil not max, so could it be the ecu or something else upgraded that i am not aware of.
any hints where and what to look foor is very welcome.
Its a rb25det i'm talking about
thanks
mike
 

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The stock Nissan ECU runs quite rich once you start modifying. AFR's in the low 10s are not uncommon on an RB25DET with higher than standard boost.

This is what a stock fuel pressure regulator looks like:



:)
 

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much better then lowering your fuelpressure would be a programmable ecu,Power FC maybe,easy to programm and allows you to do a perfect mapping for your type of fuel,mods etc.........

Alex
 

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Discussion Starter #4
thanks ,better safe than sorry ( i mean rich afr )
But can i with out a doubt go for a larger flowing turbo. Maybe not .9bar but less, but with more air flow to optain a better afr and thus more power.( using my lm-1 to see where the max point is?

mike
 

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thanks ,better safe than sorry ( i mean rich afr )
But can i with out a doubt go for a larger flowing turbo. Maybe not .9bar but less, but with more air flow to optain a better afr and thus more power.( using my lm-1 to see where the max point is?

mike
If you're using the stock ECU then increasing air flow will make it run even richer. The ECU measures air flow to determine fueling, so it doesn't matter if you do it at less boost the ECU will still run too rich and it will also retard the ignition timing. You will need something to be able to tune the afr's. A programmable ECU or at least something like the Apexi SAFC.

:)
 

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Discussion Starter #6
Simonm,
Correct me if i am wrong, so i can increase hp by changing to a better flowing turbo, till a certain point while using a stock ecu ( and stock injectors etc ). And that point to be determent by my afr number. At some point the afr must become leaner right? My problem is the ceramic turbo that i have. If i decide to go with another turbo does this mean directly another ecu / injector? Or do i have some " space " to run a bigger / better flowing turbo without directly running into buying bigger injectors and tuned ecu?

mike
 
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