Jump to content
SAU Community

Recommended Posts

Hi guys, I have a R33 GTS-T with the following mods:

FMIC

Straight through exhaust (3inch)

COld air intake system with POD filter

Turbosmart boost controller running strange boost levels.

Ok, so my intention is to have the car running at 10 PSi, however, it doesn't seem to be doing that...

When I put my foot on the accelerator, boost goes up to 11.5 PSI, then drops to 10 PSI (at about 4000 RPM)

at about 5000 RPM it will drop down to 9 PSI, then after 6000 RPM it will go up to 10.5 PSI.

What's causing this to happen, could it be a faulty boost controller?

The reason I am asking is because I want to install a Apexi NEO SAFC on the car, however, I know that the tunners will tune the car to a specific boost level, and mine are all over the placem thus, it would defeat the purpose of me instaklling it now.

Would an electronic boost controller solve my issues? Would it hold the amount of boost constant no matter what condition the car is running in (hot / cold etc)?

Or should I just get a power FC (which I am assuming can control boost levels?)?

Cheers

Link to comment
https://www.sau.com.au/forums/topic/197773-boost-fluctuation-issue/
Share on other sites

i would suggest that with the straight exhaust, it is easier for air to go through the turbine wheel than to bypass it through the tiny wastegate. so even though the wastegate is open, its going through the turbine randomly when it gets backed up.

either that, or your boost controller is somehow shagged. i'm assuming its just a bleed valve, so it should be one setting only type operation not fluctuating between like an ebc can.

a good ebc may help control it, but you may want to look into trying someone elses exhaust for 10 min. to get the wastegate enlarged by gcg etc is a big job for a gain you can only see on your boost graph. it would be possible to tune around the problem and still get a smoothish result if the tuner is ok

its something to do with how you have set the boost on the controller hence why it is up and down, similar to gain settings on the profec b style controllers, hence the fluctuation is my guess at it?

i had the exact same problem in my old R33. i removed the little boost controller and just ran the hose right through to the actuator. then went for a test drive and boost was smooth and stable. give it a go, might even just be a dodjy boost controller

i had the exact same problem in my old R33. i removed the little boost controller and just ran the hose right through to the actuator. then went for a test drive and boost was smooth and stable. give it a go, might even just be a dodjy boost controller

If you run it straight though to the actuator wouldn't you be running close to stock boost?

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

    • My thought is if you were just moving it forward and the upstream geometry remained the same, then no difference at all. But because the current one has the filter direct into the AFM inlet, you effectively have the best chance of a completely symmetric air flow profile upstream, and in, the AFM, whilst the aftermarket inlet thingo has a (small, to be sure) bend between the filter and the AFM. That would bias the flow to the outside of the bend (downstream of the bend) which might well reduce the size of the signal seen by the AFM, for the same total flow rate. Having said that: If you're proposing to make your inlet look like a hybrid of your existing one and the aftermarket one, such that there is no bend where the filter is clamped on... then I say it will be just fine. If there is going to be such a bend, then, if you can align the insertion of the AFM blade such that it is at right angles to the plane of the bend, then there is a better than even chance that the centreline velocity where the blade is will remain more or less the same, and the velocity will just be a little faster to the outside of that, and just a little slower to the inside. **This is not professional investment advice and you should consult a suitably qualified ouija board, tea leaves or the intestines of a goat for more accurate prognostication.
    • Hi Tao, Thanks for your reply.  It's been a while and I managed to get the valve stem seals replaced with the head on the car.  Unfortunately this didn't solve my issue, the car still smokes a lot after idling (to be honest during idle you can see a bit of blue smoke from the exhaust), same after deceleration. I will try disconnecting the valve cover breathers, do I leave the PCV valve in? By engine oil drain pipe, do you mean the turbo oil drain?
    • What about if you just give it direct 12v and earth?
    • Hi guys . Can someone help me  I bought an Android screen for my Nissan fuga but it won't turn on   
    • My guesstimate, with no real numbers to back it up, is it won't effect it greatly at all.its not a huge change in position, and I can't see the air flow changing from in turbulence that much based on distance, and what's in front of it. Johnny and Brad may have some more numbers to share from experience though.
×
×
  • Create New...