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Maximum power with stock MAF/fuel system

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Old Jun 13, 2007 | 03:54 PM
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bleunetizen
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From: nz
Default Maximum power with stock MAF/fuel system

Just got UTEC fitted, ran in stock mode to do some data logging.

The log tells me that I am already using 83% of injector duty, and 4.7v of MAF !

My car got drop in filter, AAM spacer, headers, stock cat, y pipe and exhaust.

I got all my parts for cam upgrade, and now I am worried that it might exceed the MAF and injector limit?
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Old Jun 13, 2007 | 04:08 PM
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From: hobbs nm
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It wont excede it. It could do around 300whp with the stock injectors.
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Old Jun 18, 2007 | 08:57 AM
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For reliablity one doesn't exceed 85% duty cylce on injectors.

I believe Nissan limits translation to 4.8 volts on MAF ~~ 255 g/sec.

Luckily cams begin to help above the VE peak [4500 rpms] where the injector duty cycle is highest.
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Old Jun 19, 2007 | 05:29 AM
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so i only have 0.1v to play with ?

found that my car runs pretty rich up top.. so i should be able to cut it down a little bit..
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Old Jun 20, 2007 | 05:57 AM
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The MAF flow vs voltage is exponential* thus 0.1 volt at the top might be 20-25% more air flow. Until you flowbench the MAF you won't know exactly.

The equation usually has a X^3.5 power factor.

Remember to reserve enough dynamic range [so that at 32F you have 4-5% left at 77F] at what ever lean AF ratio you create............

Last edited by Q45tech; Jun 20, 2007 at 06:00 AM.
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