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Discussion Starter #1
So I did it.... Bought some BOV's... you know cos I'm a boy racer at heart from the Cosworth days.

Anyway I have bought the adjustable GFB ones, as I know there can be issues with idling etc.

So with that in mind, would I install them fully set to recirculate and get it idling... then start to open to atmosphere until it starts running like crap and back them up and leave it set there... Give it a few blips or a run down the road and make sure its happy?

I'm at stage 4.25 if that has any bearing on it.

Cheers
Bart
 

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Oh dear god :(

these shouldn't suffer from idle issues unless they are leaking, the standard engines (non built) don't really suffer from idle issues unless, like I say, one of the BOVS is leaking.
 

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I will join you in being shot down, but i also like them from and always have since the cosworth days aswell. I dont have them on my GTR tho but the thought has gone through my mind.
 

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Dear oh dear! that's it i'm selling up! GT-r ownership has gone to the dogs.

.......joking aside, personally I wouldn't have them, but it's your car do what you like with it bud. It's all personal preference, and if we all liked the same things, imagine how boring the forum would be!
 
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I love dump valves. I had them on my Esprit V8 and Noble M12. The only reason I don't have them on my GT-R is that everyone says you'd not hear them because the quick gear change.
 

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Mines mapped on speed density with full atmospheric tials and I have never had any idle or running issues
 

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So I did it.... Bought some BOV's... you know cos I'm a boy racer at heart from the Cosworth days.

Anyway I have bought the adjustable GFB ones, as I know there can be issues with idling etc.

So with that in mind, would I install them fully set to recirculate and get it idling... then start to open to atmosphere until it starts running like crap and back them up and leave it set there... Give it a few blips or a run down the road and make sure its happy?

I'm at stage 4.25 if that has any bearing on it.

Cheers
Bart
TBH I am with you always made me smile coming off throttle or on gear change in my R33 to hear the BOV's
 

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Discussion Starter #12
I love dump valves. I had them on my Esprit V8 and Noble M12. The only reason I don't have them on my GT-R is that everyone says you'd not hear them because the quick gear change.
Yeah but when you give it that boost blip in town, in front of all the teenagers you get the ppssshhtt afterwards now too :p
 

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Discussion Starter #13
Mines mapped on speed density with full atmospheric tials and I have never had any idle or running issues
Can you explain in Layman's terms, I've heard it mentioned before, is it doing away with airflow meters and using Map sensor/TPS?
 

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Yeah but when you give it that boost blip in town, in front of all the teenagers you get the ppssshhtt afterwards now too :p
Hmmmm....(that's hmmm as in "hmmm.. I see" and opposed to "hmmm...really ?")

Well, I do like the blipping downshift whilst tooling around the town. It's a real head-turner !
 

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Can you explain in Layman's terms, I've heard it mentioned before, is it doing away with airflow meters and using Map sensor/TPS?
Simply put the GTR can be tuned as MAF (mass air flow) or SD (speed density).

Fuelling is based on the amount of air entering the engine.

OEM tuning strategy uses MAF. The ECU measures the volume of air entering the engine by using a MAF sensor at the beginning of the intake pipework (they are the sensors sticking out of your intake pipes near the radiator). This MAF sensor has a heated wire on its tip and the amount of cooling of said wire allows a calculation of the mass of the airflow entering the engine.

SD tuning removes the MAF sensor and uses a temperature and pressure sensor to gauge the volume of air and thus fuelling required. This pressure sensor is located after the BOV in the IC piping just before one of the throttle bodies.

The R35 OEM BOVs are recirculated as the ecu must account for the measured volume of air when off throttle. If you vent to air you're losing air that would be combusted with the fuel.

As such venting to air on MAF systems leads to over fuelling and all its associated problems.

Having the pressure sensor after the BOV on SD tuned cars means to can chavtasticslly vent to atmosphere to your hearts content.

Hope that's simple enough.
 
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