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Hi folks,

everyone Tuning and upgrading a Neo engine will run into this problem sooner or later.

The Boost sensor on the neo cuts fuel if sees lots of boost around 14 PSI.

Now as some people say the sensor is not only a failsafe, rather then also helping under vacuum setting fueling.

so to get around that Problem I will try to install a checkvalve infront of it. So under boost no pressure will arrive the sensor but it can see vacuum.

 

Has anyone tried that before?

 

I am Running 

FMIC

new Coilpacks

 A Gt3071r turbo

custom exhaust 

oilcooler and Catchcan setup

 

to install now is R35 injectors and R35 AFM

will then be tuned with nistune.

 

Off Topic:

At 250 km/h on the Autobahn B—Pillar Driverside left the Game and is not seen jet.

Does anyone know where to get one.

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https://www.sau.com.au/forums/topic/480844-boost-sensor-mapsensor-neo-engine/
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Easiest place to get one would be beside the autobahn probably....the front inner guard liners are also poorly attached for high speed so watch out for a massive noise followed by no braking on one side after the guard liner slides under the whell....

Re the ECU Boost cut, even before you hit that you will be in parts of the stock may with retarded timing and rich AFRs, designed by the factory to protect when you are outside "normal" parameters as you are at 14psi

Just do the Nistune first and fix those areas of the map, someone else can confirm but I expect it can remove the boost cut too. No need to add a checkvalve.

  • Like 1
1 minute ago, GTSBoy said:

Boost sensor can be dealt with in Nistune.

Max out the boost cut to 255, however leave it connected, as soon as you disconnect it Nistune goes crazy and always references the last column on boost.

Initial Nistune documentation said it could be disconnected and disabled however subsequent guides recommend it be connected, hooked up however disabled in the software. If not it will be an absolute pig to drive, it keeps referencing the last column on transient throttle.

According to the Nistune Neo tuning guide you can increase boost to 18 psi by increasing the  boost sensor fuel cut table to a maximum of 5100 millivolts. Is it possible to change the factory sensor for a 3 bar map sensor and then tune  to increase boost to 30 psi?

I think the best way to deal with the boost sensor's inherent upper limit would be to treat it like a wastegate and put a bleed valve on it. You put a restriction between the plenum source and the sensor, and bleed some boost out of the sense line between that restriction and the sensor. Just like a wastegate, the sensor will see a lower boost than the engine does. If you need to run 25 psi, you just bleed that down to <18 psi and it will still do what it is supposed to do.

Can’t see a bleedvalve work in that area, pressure will rise or a boostleak will be build in your application. 

 

@Duncan as soon as i saw prices on those parts i should have looked for it no matter what

Yes, even running a piggy and altering AFM Volts to reach sufficiant fueling , the car retards timing down to 3 degrees at 5 psi. Reason being i have to show him more Airflow in areas of the map where it shouldnt , to keep AFR around 12.

@NZ-GTT -i think all sensors work the same it lol give different output, based on how much the ECU works with the input it might might not work.

 

All in All, u cant get away with a piggy, after modding intake to turbo to exhaust hoping it lol run fine.

Boost sensors have a linear output of 0-5V relative to whatever the input pressure range of the sensor is. So if the factory sensor that appears to be a 2 bar map sensor was changed out to a 3 bar, the output voltage to the ecu remains at 0-5V but with a larger pressure range.

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