Jump to content
SAU Community

RB26 airflow meter upgrade Rb20 or 25??

[[d a n n y]]
 Share

Recommended Posts

paulr33 Grand Master

paulr33

Posted
Posted

rb20 and rb25 afm are same size and same calibration.

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

pnblight Mentor

pnblight

Posted
Posted

OK the rb20/25afms are a good upgrade for the gtr rb26 with a pfc as the afms will plug straight into existing harness and can be selected from a menu in the setting of the pfc ,the only thing is, it normally requires some customising of the pipe work to the turbos from the afms (the same as would be required for the z32) and the best advantage over nismo units is price and less restriction to flow (80mm over 62mm) PLUS i remend de-screening them as the mash covers about 33% of the cross sectional area of the afm and the turbulence would be significant (just make sure you run good filters).

PS. if you are aiming over 540rwhp i would go the Z32 as my rb20/25 were reading 5.03volts(5.13 is max out) at around the 529rwhp mark, my z32 now read in the low 4volt range for the same hp.

cheers

BoOsTeD_RB26 Experienced

BoOsTeD_RB26

Posted
Posted

Aftermarket piping is beneficial however it isnt required so to speak. If you dont have the funds they do sqeeze into the factory rubber piping. I did this with mine!

Piping is expensive. The Greddy suction kit is $1,100 odd delivered from nengun!

I have removed the rear screen on my afms. Not the front as I've heard conflicting rumours.

RedDrifter Experienced

RedDrifter

Posted
Posted
rb20 and rb25 afm are same size and same calibration.

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

How accurate are these figues?

Need to get a resonable guess to get me started as i am soon upgradeing my RB20 afm to z32 using the stock ecu.

7heavn Experienced

7heavn

Posted
Posted

rb20/25 afm's are the same . I have rb25 afm's on my GTR if you have custom pods then they will probably not bolt up to the 80mm afm's like I found with my blitz pods. I just bought two gts-t pod adapters and mounted new filters . The rubber turbo intake pipes just squeeze over the back of the 80mm afm's help to heat them up they slip on easier. Have a look in my gallery have a pic of the my engine bay with rb25 afm's .

pnblight Mentor

pnblight

Posted
Posted

in my opinion if your looking to replace the std afms it means you are looking over 400rwhp as i believe that about where the std afms start to run out of head room, and that be so you are starting to look at serious power levels.

So concider this while people go full on with big exhausts and plenums and coolers to etc etc why would you run a resistive intake where the air has to be drone in (not pumped etc)

so the choice of good filters and intake piping and large not resistive afms are very important as this is the first link in the chain

(as what air you are trying to pump through the rest of the system must pass through here first and must do so under no pressure only by the vacuvm of the turbo intake)

eg why put a ~2"x2(ID)grilled afm on the intake and a twin 3" exhaust or 4"intercooler

the grill takes up about 33% of the cross sectional area of the afm and serve no purpose but to add resistion to air flow(i believe the only reason the grills are there is to stop objects touch the afm elements).So if you run good filters and dont go putting tools or fingers into them the grill is redundant.

my 2c

GTR-Ben Proficient

GTR-Ben

Posted
Posted

I made a post a while ago about running the AFM inline as well as increasing the ID of the pipe the AFM is installed into to allow more power before maxing out etc.. I got no responce..

I will be trying this on my own setup though. The AFM probe is simply O-ringed into the pipe. I think if I run a single GTS-T 80mm AFM inside a 4" pipe, this will have the same flow as 2 x 3" pipes, saving a lot of space :(

e.g a 80mm GTS-T afm in a 4" pipe should in theory allow 453rwkw. I'm not sure how this would effect the resolution however. I was hoping an expert could shed some light..

Seems like a lot easier and cheaper way to do things if it works. I know of a few cars running AFM's inline on the pressure side of the piping. Normally after the Intercooler.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • GTSBoy
      r34 Skyline 25 Gt four GTR conversion (ENR34)

      By GTSBoy · Posted

      Greg speaks wisdom. These dirty old Datsuns are only value when they are cheap. When they are not cheap, there is no value. Sounds contradictory, but it's true. We are now 20 years past the hey day of modifying cheap 90s JDM cars for small amounts of money. This is a different world. If you are rich and can afford not to care about what is effectively wasting money on an old Datto shitter, then I have no reason to argue against it. But if you are wanting to experience what we all experienced back in 2005 (and I bought my car last century!) then there is no way to do it.
    • Kinkstaah
      r34 Skyline 25 Gt four GTR conversion (ENR34)

      By Kinkstaah · Posted

      Short answer: No. Medium answer: No, because you still need to conjure the things out of thin air to bolt them to a NA to make it a NA+T. Long Answer: No - The things you need to conjure - meaning a turbo, intercooling, manifolds, exhaust, intake/manifold/piping, clutch, injectors, fuel pump, AFM (?), ECU + Wiring (woo, N/A loom fun) have to come from somewhere. You could have many scavenged these things from an OEM car that someone had upgraded from and use some of these. This will be cost prohibitive now, especially so in the USA. You'd probably pay the same for newer, upgraded components that are better than old OEM stuff from 25-30 years ago. None of these big ticket items are re-usable for the N/A car. Why not buy new and upgrade while you're there? The only real consideration is turbo and fuel sizing and determining whether you want to stay within the bounds of the OEM engine or get into rebuild territory. These limits ARE lower with a N/A motor and especially N/A gearbox at the starting point. And if you're gonna upgrade those then you may as well consider having them built to begin with. Because everyone here knows you're never far from that next engine rebuild once you start making the power you want... The cars you see on the internet and SAU etc have been built over decades. If you're really clued in... you would sell your US car to somebody for what you paid for it. You would then scour AU JDM pages or SAU and buy a car like Dose's on this forum with your powerful American Dollar. This will save you so much money in the long term. Importing it could be tricky. Or it might not because USA. I have long said the only reason 90's Japanese stuff took off was because a) Japanese people had Japanese cars so that is what they used b) Australians could import these cars to Australia with very minimal changes and use them on the road here c) Neither country had well-priced access to US or EU Sports Cars. I don't believe the JDM scene would have taken off in Australia at all if we had EU priced EU BMW M offerings, or more especially the AUS V8 Scene would never have existed if we had the multitude of US cars like Camaros, Mustangs, Corvettes at the prices you folks do. After all - Do the math. I would say put a V8 in your R34 and that's the smart way forward. It is. I did it. I know this from my own experience. But at that point there's no reason to simply not buy a C5 or C6? It would be simpler and easier and cheaper and bette-
    • AdiR34
      r34 Skyline 25 Gt four GTR conversion (ENR34)

      By AdiR34 · Posted

      Reading all this... hurts lol. I have an ENR34 5MT and I paid an inflated USA price for the car alone, had to do tons of preventative maintenance past that, and so I'm over $30K USD into the car already and haven't even touched power.  I wanted to +t it. Not even trying to make GTR numbers, I'd be happy with 250hp.  Can I get away with paying much less to make that happen?
    • Milkmun
      The Evolution Of "night Fury"

      By Milkmun · Posted

      Damn you’ve done well, definitely snapping necks.
    • acsplit
      SAU VIC Motorkhana Saturday 14th June Winton + Entry List & Accomodations details

      By acsplit · Posted

      Great weekend and event. Open fire at the caravan park, perfect weather all day and a great feed and a couple of drinks at at awesome country pub.
×
×
  • Create New...