Jump to content
SAU Community

Recommended Posts

When my R33 GTR comes on boost you can hear the air being sucked in obviously but it sounds as if it is cutting in and out and is making a chopping sound while accelarating on boost. Does anyone have any ideas on what it could be? and is it bad?

The car does not stutter while it is doing this either. My car is standard but the boost restrictors have been taken out.

Any help would be appreciated.

Cheers

Edited by Cooper
Link to comment
https://www.sau.com.au/forums/topic/127628-gtr-air-chopping/
Share on other sites

Called compressor surge.

Search for it and sift your way through the flutter threads, and you will find explanation of this and possible solutions.

I’ve heard having aftermarket bovs on a gtr sometimes causes this.

Stock gtr bovs plumbed back as is from factory seems to fix issue.

If you have stock bovs already, then I’m stumped.

cheers

it could be one of two problems you are seeing. the first one is compressor chuffing or shuffling, where you can hear compressor surging at idle and low rpm, it sounds like talking into back of a fan or a vl turbo style flutter between each of the turbo's. this is commonly associated (that we've seen) with bov changes and/or custom intake piping.

the other one that comes to mind is compressor wheel chopping. my gtst does this. as its coming on boost you can hear like a slicing noise, a bit like a hi speed food processor in coleslaw mode. ive had this since day 0 and a few other gtst have this same behaviour. i dont think its a problem, just an induction noise based on the compressor wheel

I had this same problem with my rb20det. Does it while i accelerate between 3000-4000rpm and more often in a higher gear (etc 5th gear on the highway). I have a adjustment nut on my internal wastgate arm which allows me to turn the boost up without a boostcontroller. What i did was loosen the nut back to standard boost and the problem was fixed. To whether i have a faulty wastegate actuator, ecu cannot handle the amount of psi (11spi) or my turbo is f*cked im not sure. I think that the wastegate is flapping open and closed therefore causing a sudden loss of pressure in the exhaust wheel causing the turbo wheel slow down and the presure built up in the intercooler piping blows back out the turbo (flutter). It is hard to explain.

If anyone else has these problems please post.

^^^ I am pretty sure the BOVs are working but saying that im not 100% i might have to take them off on the weekend and check them out, all the hoses and lines are all connected, as far as i can see anyway. Is there an easy way to get to the BOVs so that i can check them out?

I dont see how it would have anything to do with the BOV. You say that it happens when you are accelerating (ie throttle body is open).

I think ^^^people above are getting mixed up with the flutter noise that happens when take your foot off the accelerator. If that is your problem then i would suggest checking your BOVs.

Pull off your intake pipes and see if there is any shaft play in either of the turbos.

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


  • Similar Content

  • Latest Posts

    • roof rail delete used to be a thing, they were made locally for a while too
    • I can get more photos of it here soon and I plan to make a thread detailing the process. I received the car this way and it sorely needs refinishing. That is probably the most appealing photo of it. Up close it is fading, cracked, and needs to be re-glued. Depending on their condition I'm on the fence between refinishing or making a new set.  Another angle hiding the pimples and razor pumps  
    • According to this thread the RS4V with build plate RC40 comes with the R200 diff @ 4.083 ratio as well (mine has said RC40 denotation). We may need to check if the axle stubs are the same pattern as well. The auto subframes have longer axles. However I think yours being a later Series 2 as well, we should have the same bolt pattern for the diff stubs. Unless your upgraded rear also has upgraded axles. Either way, I would not be opposed to pulling the covers to check so I can inspect that  fancy rear core  Also I don't have HICAS. I don't believe that should change things but I hope the people here with heaps more experience than me can correct me if I'm wrong   Let me know if you want to attempt to make this work and I can get some pictures of mine from under the car. 
    • It's not that straightforward. For example I have had this code because my ignitor/power transistor wires were unplugged. It knows something is wrong but has no idea what it means. If you want to actually diagnose this I recommend following the service manual flowchart for code 21. Ohm out the harness, coilpacks, inspect the ECU, etc. And again, it's entirely possible for there to be no problem at all but if you're running a different coilpack it'll trigger the code because it doesn't like what it sees.
    • If it (the code) wasn't still current, it should have gone away by itself by now. No, nothing it 10/10. But it is quite likely. Everything else to do with the ignition could still be responsible (which is wires and connectors). The car is an old piece of shit now, so all the wires and connectors are also old pieces of shit.
×
×
  • Create New...