Jump to content
SAU Community

RB20 AFM's onto a GTR

Parag0n

By Parag0n,
in Engines & Forced Induction

 Share

Recommended Posts

Parag0n Mentor

Parag0n

Posted
Posted

Hi all,

I've heard different tales of when the GTR AFM's bottom out, some say 280rwkw others 350rwkw, does anyone know an accurate figure?

Anyway, I'm looking at putting on RB20 AFM's as I am told that two of these on a GTR can support approximately 350rwkw? Is this correct.

If so do you need an adapter of sorts or any other complications?

Thanks, Gary.

Link to comment
https://www.sau.com.au/forums/topic/50482-rb20-afms-onto-a-gtr/
Share on other sites
Sydneykid Grand Master

Sydneykid

Posted
Posted

Hi, I have posted this table a few times, but just in case you missed it.

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

Please note that this is only an indication, every engine is different and tuning makes a big difference. For example, I have seen a GTR equiped with twin Q45 AFM's make 1100 bhp.

RB20/25 and Z32 AFM's are all 80 mm OD, that's outside diameter, not ID that's inside diameter. There is no real difference between an RB20 and an RB25 AFM. On the other hand the Z32 AFM is calibrated differently, so at the airflow the RB20/25 AFM shows max voltage, ~5 volts the Z32 afm is only showing ~4 volts. This means when the airlfow gets higher the Z32 can still show voltage increases to the ECU.

Q45 (Infinity) AFM's are 90 mm (OD), so they have the same calibration advantage but they are also larger in diameter for less restriction.

Hope that helps :cheers:

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

    • jtha7
      Replacing turbo water line - any recommendations or advice?

      By jtha7 · Posted

      Hi all, Restoring r33 series 1 rb25det. All the heater hoses were on their way out, have replaced them and put it all back together. After testing I noticed a small leak from behind the head on the actual metal water line to the turbo when cars warm. I tried running a longer hose over it but it kept leaking...   I am about to take the (stock) manifold off again😔 to change the water line does any one have any lines they recommend? I was looking at Aeroflow Turbo Oil & Water Line Set but not sure what everyone else recommends. Car is completely stock but want to upgrade turbo eventually. it looks like ill have to disconnect a lot just to replace these lines so if there's anything else recommended to do please let me know. Thank you in advance!
    • MBS206
      RB20DE NEO smallbox clutch.

      By MBS206 · Posted

      From memory, on the R33 GTSt at least, while everyone says "It's not adjustable", I found when I changed clutches in mine, it just needed a small adjustment on the rod length. But be very wary here, as you could end up trying to push the pushrod in the master too far, or blowing out the slave.   Most likely though, if the master/slave isn't bypassing internally or leaking out, then the throw out is the wrong height compared to the fingers on the clutch, so when it moves to disengage the clutch, it isn't 100% disengaged. You can check part of this out too by jacking the car up, having the engine running, put your foot on the clutch and try to engage 1st gear. If it goes in pretty easy (Compared to the ground) and/or the wheels start turning a fair bit and it takes a bit too much brake pedal to bring them back to a stop, this is likely the issue.  I'm not sure if you can adjust the height of the forks etc in these though, it's been that long since I've touched any RB gearbox.
    • MBS206
      Lock up the old for sale / wtb threads.

      By MBS206 · Posted

      That's all good, I thought I was missing some interesting feature! Maybe @PranK can double check if that is something that is meant to be operating or not.
    • Kapr
      RB20DE NEO smallbox clutch.

      By Kapr · Posted

      I hope that is not something that bad. From what i remember he said that only first gear is "hard" to get in and that he has couple of ideas what to try next but idk 😕  hope it is not gearbox out. I will let you know.
    • GTSBoy
      RB20DE NEO smallbox clutch.

      By GTSBoy · Posted

      If it's not the hydraulics, it is probably gearbox back out. Usually as per @Duncan's post, or otherwise associated with not getting the throwout fork positioned correctly. All the way up to catastrophically bolting shit back together without it being aligned properly and wrecking the clutch/input shaft/flywheel/something else.
×
×
  • Create New...