Jump to content
SAU Community

I'm Getting Bad Boost Cuts/boost Leak

Richy

By Richy,
in Engines & Forced Induction

 Share

Recommended Posts

Richy Rookie

Richy

Posted
Posted

my r33 gtst is boost cutting or leaking, i'm not quite sure which one it could be but basically whenever i boost more than 5 psi, boost just wont hold, it either spikes at high rpm's or i don't feel the boost at all. For example the other day i set the boost to about 9 psi and at full throttle it spikes a little (not much) to 4/5k rpm and past that it will just start cutting like it doesn't wanna go any further. So now it's set back to 5 psi but i need to get rid of this problem. I've been told so many different things like Coilpacks need to be changed, intercooler could be leaking cos a friend installed it not a mechanic, BOV could be leaking etc.

Link to comment
https://www.sau.com.au/forums/topic/167012-im-getting-bad-boost-cutsboost-leak/
Share on other sites
mad082 Grand Master

mad082

Posted
Posted

do you have a front mount? if you do where do you have the controller taking its reading from? if it is from the bov hose then relocate it. have a nipple installed on the hot intercooler pipe.

what does the cutting feel like? is it a hard start/stop? or is it like a spluttering? if it is a spluttering then try gapping your plugs down, and taping up your coils.

bubba Grand Master

bubba

Posted
Posted (edited)

I had the similar symptoms the other day on my 32.. a hose clamp had popped off but the pipe was still in the hose (i.e. it hadn't popped all the way off). Was driving back from the shops and it would start to spool then at 4k it would kind of cut out.. I've had a hose pop right off on the highway once before and could barely keep the thing idling and driving it to the nearest exit was a complete bastard.

This time I could still drive if didn't go over 4k.. got home, popped the bonnet and found a hose clamp where the cooler piping joins the crossover pipe had let go :)

BUT could be the stock ECU's fuel cut happening on your 33 :)

Edited by bubba
mad082 Grand Master

mad082

Posted
Posted

bubba you could be onto something there. if you had a hose that wasn't sitting on right, and once it had a fair bit of force on it it was opening a gap up it would cause a loss of boost pressure and the car to run overly rich, which could be the cause of this issue. it would be worth checking the cooler piping.

Richy Rookie

Richy

Posted
  • Author
Posted

i'm gonna try taking off the intercooler and connecting it straight to the turbo, the cut feels like the airs just spluttering everywhere its spooling but just feels like its going nowhere. i got a stock ecu. I'll post results of the intercooler removal tommorow. thanx

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

    • MBS206
      New fix for low tyre pressure from bmw

      By MBS206 · Posted

      Yep, pretty much what you said is a good summary. The aftermarket thing just attached to the rim, then has two lines out to valve stems, one to inner wheel, one to outer wheel. Some of the systems even start to air up as you head towards highway speed. IE, you're in the logging tracks, then as speeds increase it knows you're on tarmac and airs up so the driver doesn't even have to remember. I bet the ones that need driver intervention to air up end up seeing a lot more tyre wear from "forest pressures" in use on the highway!
    • sunsetR33
      Anyone know this frontpipe?

      By sunsetR33 · Posted

      Yes, but you need to do these type certifications for tuning parts. That is the absurd part here. Meaning tuning parts are very costly (generally speaking) as well as the technical test documentation for say a turbo swap with more power. It just makes modifying everything crazy expensive and complicated. That bracket has been lost in translation many years ago I assume, it was not there.
    • dbm7
      New fix for low tyre pressure from bmw

      By dbm7 · Posted

      Hahaha, yeah.... not what you'd call a tamper-proof design.... but yes, with the truck setup, the lines are always connected, but typically they sit just inside the plane of the rear metal mudguards, so if you clear the guards you clear the lines as well. Not rogue 4WD tracks with tree branches and bushes everywhere, ready to hook-up an air hose. You can do it externally like a mod, but dedicated setups air-pressurize the undriven hubs, and on driven axles you can do the same thing, or pressurize the axles (lots of designs out there for this idea)... https://www.trtaustralia.com.au/traction-air-cti-system/  for example.... ..the trouble I've got here... wrt the bimmer ad... is the last bit...they don't want to show it spinning, do they.... give all the illusion that things are moving...but no...and what the hell tyre profile is that?...25??? ...far kernel, rims would be dead inside 10klms on most roads around here.... 😃
    • joshuaho96
      Anyone know this frontpipe?

      By joshuaho96 · Posted

      You're just describing how type certification works. Personally I would be shocked to discover that catalytic converter is not in the stock mounting position. Is there a bracket on the transfer case holding the catalytic converter and front pipe together? If so, it should be in stock position. 
    • GTSBoy
      New fix for low tyre pressure from bmw

      By GTSBoy · Posted

      You talking about the ones in the photo above? I guess that could make sense. Fixed (but flexible) line from the point up above down to the hubcap thingo, with a rotating air seal thingo. Then fixed (but also still likely flexible) line from the "other side" of the transfer in the hub cap thingo up to the valve stem on the rim. A horrible cludge, but something that could be done. I'd bet on the Unimog version being fed through from the back, as part of the axle assembly, without the need for the vulnerable lines out to the sides. It's amazing what you can do when you have an idea that is not quite impossible. Nearly impossible, but not quite.
×
×
  • Create New...