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RB20/RB25 AFM max power?

Remix-

By Remix-,
in Engines & Forced Induction

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GunMetalR33 Mentor

GunMetalR33

Posted
Posted

Its not so much the power but the amount of Air that it can measure. For example a HKS GT-RS will make a certain power level at 14 psi and a standard turbo will make a bit less power. What I am trying to say is that I think the rb25 AFM will max out at about 14 psi. Now depending on what turbo you have your power levels at 14 psi could be anything from 180rwkw upwards.

If your rb25 has a stock turb then the stock AFM should see you to about 200 rwkw...

hope that makes sence :)

DRFTR33 Contributor

DRFTR33

Posted
Posted

my airflow meter maxed out at 12psi and i was making just over 200kw

there are alot of things that you have to take into acount

you have to remember that hot wire air flow meters work by heating the little wire in side, when air passes over it, it changes the resistance in the wire so it takes more voltage to heat it and thats the signal that is send back to the ecu. once the voltage reaches 5.13 volts it cant heat the wire anymore and that is when you are maxed out

air density(temperature) plays a big part in this as colder air will cool the wire easyer

that i why mine maxed out at around 12psi and some of you guys can run up to 14 psi without a problem

i hope this has helped you

DRFTR33 Contributor

DRFTR33

Posted
Posted
what symptoms would you have if your air flow meter was being "maxed out"

like if you didnt have an FC with commander telling you exactly whats going on. how could you tell?

Cheers

if your running a standard ecu it feels just like your boost cut and if you havnt hit that yet, it feels like your going to be thrown though your front windscreen, its a very sudden jolt. thats the best way i can explain it

Cake Mentor

Cake

Posted
Posted
I changed to rb20/25 afm's on my GTR becuase the std ones ran out of head room. I'm running 2530's at 1.2bar with rb25 afm's(same as rb20) and I more headroom then I need . Much cheaper option then z32's and the rb ones just plug straight in .

that's what he want's to hear :cheers:

to others he's talkin twin rb20/rb25 afm's on a gtr

paulr33 Grand Master

paulr33

Posted
Posted

This is from Sydneykid

Rule of thumb for Air Flow meters RWKW & Engine BHP

------ ---- OD ---- RWKW ---- RWKW ---- BHP ------ BHP

No of AFM's ---- ------- 1 -------- 2 -------- 1 -------- 2

RB26 ------ 65 ------ 149 ------ 299 ------ 271 ------ 474

RB20/25 --- 80 ------ 226 ------ 453 ------ 376 ------ 683

Z32 ------- 80 ------ 255 ------ 511 ------ 415 ------ 763

Q45 ------- 90 ------ 302 ------ 605 ------ 479 ------ 890

GunMetalR33 Mentor

GunMetalR33

Posted
Posted

Your Engine warning light will also flash in a particular sequence when your AFM maxes out. This is often mistaken for knock... I am not sure what the 2 different sequences for knock and AFM Max out are though...

Is their a way of checking if the stock AFM is maxing out? without using an aftermarket ECU?
Beer Baron Grand Master

Beer Baron

Posted
Posted
Is their a way of checking if the stock AFM is maxing out? without using an aftermarket ECU?

Sure can mate. if you have the car on the dyno the output voltage can be checked using a multimeter. anything over 5volts and the AFM is near max. infact with a pin out diagram you may be able to check what voltage the AFM is sending to the ecu (thus not needing to check it in the engine bay), this way you could check it on the street/strip instead of having to use a dyno.

  • 3 years later...

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