Jump to content
SAU Community

Rb25 Over Boosting

PyroIndustries
 Share

Recommended Posts

PyroIndustries Contributor

PyroIndustries

Posted
Posted

i put a turbosmart boost valve in 2 days ago. set it up and everything was fine. yesterday it started boosted like crazy no matter what i do with the vaule. Today i put in a replacement valve with a new one and same problem still.

also when i give it a bit it sometimes cuts out for a split second giving the car a big jolt.

can anyone give me any advice? im sure that its not the valve that the issue.

thanks

dazza

Link to comment
https://www.sau.com.au/forums/topic/262806-rb25-over-boosting/
Share on other sites
PyroIndustries Contributor

PyroIndustries

Posted
  • Author
Posted
Bypass the boost controller ( Back to 100% stock ) and see if it still does it. Problem may be wastegate actuator

have bypassed it and i did go back to stock.

yes its the right way. lol

what would be causing the airflow cut?

**RB2530** Proficient

**RB2530**

Posted
Posted
have bypassed it and i did go back to stock.

yes its the right way. lol

what would be causing the airflow cut?

Ummm excessive airflow due to poor boost control....Its a feature of the standard ECU that prevents engine damage due to too much airflow caused by increased boost or overboosting ...It acts in the region of peak torque 4000-5000 rpm on the stock engine. As soon as AFM voltage exceeds a threshold it cuts spark until air flow drops..

Don't worry...Its meant to be there...Its probably saved you from a big engine rebuild bill...

PyroIndustries Contributor

PyroIndustries

Posted
  • Author
Posted
Ummm excessive airflow due to poor boost control....Its a feature of the standard ECU that prevents engine damage due to too much airflow caused by increased boost or overboosting ...It acts in the region of peak torque 4000-5000 rpm on the stock engine. As soon as AFM voltage exceeds a threshold it cuts spark until air flow drops..

Don't worry...Its meant to be there...Its probably saved you from a big engine rebuild bill...

yeah that spot on to what it was doing.

so how do i drop the boost when 2 brand new boost valves wont regulate the boost?

zebra Grand Master

zebra

Posted
Posted
yeah that spot on to what it was doing.

so how do i drop the boost when 2 brand new boost valves wont regulate the boost?

Rip out boost tee and throw it in the bin :banana:

then enjoy not blowing your standard turbo into a million bits :D

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

    • 25zenki
      S1 rb25/s14 starting problem

      By 25zenki · Posted

      This car has run before on this z32 ecu can get the part number for you, I have tried with no AFM it didn’t change anything, I compression tested today 140-150 across all 6 cylinders, also set fuel pressure to 43psi. The only weird thing was cylinder 1 plug was black and fouled other 5 cylinders were just wet with fuel. Spun cas by hand and confirmed injectors are clicking 
    • MBS206
      new 1.5 LSD issues/concerns

      By MBS206 · Posted

      Since you came here to ask for help, have you thought about answering our questions, that might help us lead you to why it was skipping, or have you given up on getting advice?
    • GTSBoy
      new 1.5 LSD issues/concerns

      By GTSBoy · Posted

      A 1.5 way is a 2 way. It is just a 2 way with a less aggressive ramp on overrun.
    • GTSBoy
      Boost cut after swap(RB25DET NEO) R34

      By GTSBoy · Posted

      The ABS and/or TCS being missing/broken will not cause the engine to misbehave. It just casues CEL to come on and annoy you. The CEL is useless if it is always on, so you have to do the things you have to do to get rid of it, so it can be useful. Being a Stag ECU, then yes, it will not expect TCS to be present. But it will expect ABS to be present and working. You will need to either make the ABS CU talk to the ECU (don't ask me what that will take on an NA R34), and make sure the hardware is working....or, you just need to blank it out in Nistune. Do not persist with the stock ECU. You will just have problems. Gte it Nistuned. Start from there. DO YOU HAVE A BOOST SENSOR? The ECU's boost sensor that it. It is connected to the loom at the rear of the coil cover. Usually rides on the firewall on an R34, but is usually bolted down to a bracket along with all the other crap at the back of the coil cover when a Neo is dropped into another car. If you do not have it, the ECU will shit the bed. So, do you have one?
    • Kapr
      Boost cut after swap(RB25DET NEO) R34

      By Kapr · Posted

      So sadly the fuel pump etc was not it. The pump and filter is new and it is still cutting around 4000 rpm. A read something about ABS/TCS (engine is from stagea and ECU too so no TCS) and i dont know for 100% that my car has ABS. It has ABS "cube" in engine bay but i dont think it works(or at least from my braking experience). Can be something like that?  I will be driving the car next week to Nistune tuner to properly see what is wrong...  
×
×
  • Create New...