Flow Potential Of R34 Gt-r Air Flow Meters?

[xanavinismo]

Hi all,

How much power can the stock R34 GT-R air flow meters handle before it needs to be upgraded to bigger afms (Z32's) for more power?

To my understanding, isnt it around 300rwk's and not much more?

Cheers,

[kefe69]

Don't now about max but i'm still using stock and i have 310awkw. As soon as i can i will be upgrading them though..

[Duncan]

they will run to maximum voltage somewhere between 280 and 300kw. From there the tune is "blind", there is only a single point in the ECU for all airflow above 5v which means it is compromised in both fuel and timing to make sure it stays safe.

[Swiper the Fox]

they will run to maximum voltage somewhere between 280 and 300kw. From there the tune is "blind", there is only a single point in the ECU for all airflow above 5v which means it is compromised in both fuel and timing to make sure it stays safe.

yep

[Guilt-Toy]

yep

what he means is if its tuned and maxed out at 20psi, if the car overboosts or you turn the boost up the state of tune will not change as the ecu does not know the boost level has changed so it could cause detonation or a too lean of a mixture for the extra boost.

it works the other way as well, if the afm max's out at 17 psi and you tuned the car to 23psi, then you decide to turn the boost down to 17psi, then it will run too rich and you won't be getting the right power / mixtures for that boost level

So its kinda ok but not recomended to tune the car with a maxxed out AFM, if you dont intend on changing the boost at all then you can possibly get away with it if you have a decent boost control that will never fail and overboost

[xanavinismo]

Thanks everyone for all of your replies.

I will be having the following mods:

Garrett GT2860-7 turbos

Apexi Power FC

Apexi Power FC Boost Control Kit (running 1.2, or even 1.3 bar)

Nismo 600cc injectors

Nismo fuel pump

Apexi Power intake kit

HKS cam pulleys

Tomei Poncams 260's type B

HKS Front pipe

HKS Cat

Blitz NuR cat back

So im guessing that with all of the above mods and the boost that I hope to be running (1.2 or even 1.3 bar) I should upgrade afms? I was thinking of the Nismo afms...

Cheers,

[Beer Baron]

yeah I would. and I would get the nismo afms too. I went new gen nissan Z32s on the last GTR, and nismos on this one. performance wise they are very, very close. and the nismos have the advantage of being standard size.

[xanavinismo]

yeah I would. and I would get the nismo afms too. I went new gen nissan Z32s on the last GTR, and nismos on this one. performance wise they are very, very close. and the nismos have the advantage of being standard size.

Oh ok so the Z32's are actually bigger than my stock ones? Which means they wouldnt bolt straight up?

And the Nismo ones would use the same ECU plugins?

Also, you dont think its over kill to get the Nismo ones for my application with the mods I have listed above?

Cheers,

Edited June 10, 2009 by xanavinismo

[Bakes]

What about Power FC D Jetro Glen? Then you wont have to run air flow metres at all. Just unplug them.

Thats how mine is with my Vipec ECU

[R31Nismoid]

For 1.2-1.3 bar, i wouldnt bother upgrading until you actually know you've maxed them. I think its undue spending at this point.

You might well find you might come close, but they wont actually max @ that boost level. Every setup is different of course

And ye, if you do max them - Nismo all the way. Z32's are too much of a stuff around.

www.perfectrun.com.au are the cheapest for Nismo's that i've found recently... they can get em cheaper than an importer i know

Perfect run (providing stock) should have em here in 2-3 weeks so its not as if you have to wait forever anyhow.

[xanavinismo]

What about Power FC D Jetro Glen? Then you wont have to run air flow metres at all. Just unplug them.

Thats how mine is with my Vipec ECU

Hi Bakes, unfortunately I already have my normal Power FC installed so its too late for D Jetro?

Oh and R31Nismoid, thanks for your input. I am most likely heading towards that direction where I get the car tuned and see if they do actually max out cos then I can always replace them with the Nismo ones if necessary.

On a bit of a side note, should I also upgrade the fuel pressure regulator to handle the Nismo 600cc injectors & Nismo fuel pump along with the other mods I have?

I am thinking of the Nismo adjustable fuel pressure regulator...

Cheers,

Cheers,

Edited June 10, 2009 by xanavinismo

[R31Nismoid]

No, you do not need a regulator. Factory Nissan all the way.

If your injectors suit the power (which they do), the factory FPR always wins out as its free

[Bakes]

Glen, if you want a Nismo fuel pressure regulator I have one I am going to sell. Its only done ~3000Klms.

PM me if your interested.