Jump to content
SAU Community

Rb25Det Not Boosting Well

rb25debt

By rb25debt,
in Engines & Forced Induction

 Share

Recommended Posts

rb25debt Contributor

rb25debt

Posted
Posted

Hi guys, i have a r32 with a rb25det neo in it from a rs4 Stagea. Car was originally auto but is now manual converted.

the problem i have is, it will boost up to around 8 psi and the gate opens. But it doesn't really feel like its boosting. Its also a bit hesitant.

It has a master power t04e, front mount, all the basic mods. Ive only recently got it and have just began tidying it up. I'm pretty sure it hasn't been tuned for the t04e so that could be the problem. But the thing is when it hits boost it almost feels like its letting all the boost out, sort of like a exhaust leak.

Im just learning things atm and trying not to use the turbo in the mean time.

Any ideas?

Thanks for any help guys

Link to comment
https://www.sau.com.au/forums/topic/449751-rb25det-not-boosting-well/
Share on other sites
GTSBoy Grand Master

GTSBoy

Posted
Posted

Nonononononojnononopnonononodondonondonooooooo

You can't try to boost up a Neo ECU past about 11 psi on a STANDARD turbo without causing it to clip the air-flow meter, hit the boost limit (there is a boost sensor connected to the crossover pipe) and various other shits and giggles.

If you try to boost it up on a BIG turbo, then expect the shits and giggles to start happening at lower boost. 8 psi would be about right.

The thing will make boost, but the ECU will overfuel and cut timing so badly that it will be slow slow slow. Push it further and they will actuall give you a very nasty hard cut.

If you keep driving it like this you will damage it. You have to either piss that shitful turbo off or do something about the ECU (and the AFM and the injectors and probably the fuel pump).

rb25debt Contributor

rb25debt

Posted
  • Author
Posted

Nonononononojnononopnonononodondonondonooooooo

You can't try to boost up a Neo ECU past about 11 psi on a STANDARD turbo without causing it to clip the air-flow meter, hit the boost limit (there is a boost sensor connected to the crossover pipe) and various other shits and giggles.

If you try to boost it up on a BIG turbo, then expect the shits and giggles to start happening at lower boost. 8 psi would be about right.

The thing will make boost, but the ECU will overfuel and cut timing so badly that it will be slow slow slow. Push it further and they will actuall give you a very nasty hard cut.

If you keep driving it like this you will damage it. You have to either piss that shitful turbo off or do something about the ECU (and the AFM and the injectors and probably the fuel pump).

Ok sweet as man, theres not much that can be done with a neo ecu aye. would my best option just be to put a standard 25det turbo on it? I don't want to make big power, i'd prefer it to be reliable and standard.

GTSBoy Grand Master

GTSBoy

Posted
Posted

Ok sweet as man, theres not much that can be done with a neo ecu aye. would my best option just be to put a standard 25det turbo on it? I don't want to make big power, i'd prefer it to be reliable and standard.

Yes, there is something you can do about the Neo's ECU. It is actually far better than an R33 ECU in that regard. You can get it Nistuned (which is a tunable daughterboard which gets installed inside the ECU) for, well, about $600 I guess. If it then needs to be tuned you pay for dyno tuning too.

You'd actually be well advised NOT to put a std 25 turbo on there. They are all getting a bit old. They are ceramic. They can and will die at random.

I suggest that you do some searching on here amongst the millions and millions of posts about what a good turbo option would be for you. I'm not going to type it all out again.

rb25debt Contributor

rb25debt

Posted
  • Author
Posted

Yes, there is something you can do about the Neo's ECU. It is actually far better than an R33 ECU in that regard. You can get it Nistuned (which is a tunable daughterboard which gets installed inside the ECU) for, well, about $600 I guess. If it then needs to be tuned you pay for dyno tuning too.

You'd actually be well advised NOT to put a std 25 turbo on there. They are all getting a bit old. They are ceramic. They can and will die at random.

I suggest that you do some searching on here amongst the millions and millions of posts about what a good turbo option would be for you. I'm not going to type it all out again.

Cool, cheers for the help man, i appreciate it. I'll look into the Nistune daughterboard as it sounds like the best option for me. I also noticed there was a hole in the hose that comes of the j pipe. Would you know what that part is called as i need a replacement one.

rb25debt Contributor

rb25debt

Posted
  • Author
Posted

If you're in Sydney and want a road tune for your basic mods for your Nistune I have both software, hardware and a portable wideband.

Cheers bro i live in New zealand though, i'm pretty keen on getting a Nistune

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

    • joshuaho96
      Potential MAP Reference Point

      By joshuaho96 · Posted

      Isn't there a fitting on the back of the balance tube? That's what the OEM boost gauge uses.
    • GTSBoy
      Potential MAP Reference Point

      By GTSBoy · Posted

      Getting a decent signal from all 6 throats is a challenge. I don't know for sure, but I suspect that the stock balance tube is not ideal for it. I have done it on an ALFA 4 cylinder (about 35 years ago, so don't ask for too many details). We drilled 4x holes in the manifold runners, put in some fittings and ran hoses to a decent sized (I think it was about 20mm diameter) pipe that ran the length of the inlet manifold. So, it was quite a decent volume. There is a "tuning" balance to be found between the volume of the common plenum on such a thing and the diameter of the pipes running from it to the runners. You need the volume to be large enough to damp out the sharp spikes in pressure signal you get as each runner gets sucked on by its cylinder, but not so large that it becomes too slow to respond to actual changes in MAP. And you need the hoses to be small enough to transmit the signal quickly, but not so small that they delay the signal. You might have to have more than one go at it, if there isn't any actual success based wisdom to be had here. Hopefully there is. Anyway, I would not do it on only a couple of cylinders. I would also not care about "permanently modifying a part". Just bloody drill holes and make stuff better. There is nothing sacred about any GTR unless it is a genuine museum piece that you shouldn't be modifying at all anyway.
    • MBS206
      NC MX5

      By MBS206 · Posted

      He's still joining you, he's just delayed it and won't have the fulleh sick ITBs...
    • Kinkstaah
      R34 GTT front hood lip

      By Kinkstaah · Posted

      The strange thing is this is a URAS front bumper (or clone of it). The bumper actually does not sit flush with the GTT hood - You need the addon to make the hood 'long' enough to reach the bumper. I have no idea why they didn't incorporate this piece into the bumper itself.. instead of sticking it to the hood instead.
    • AdiR34
      R34 GTT front hood lip

      By AdiR34 · Posted

      Another thought on this OLD topic: When you paint your bonnet lip, leave a small unpainted back lip/line along the back of the lip, where it rests on the bumper. That way, the line in the back is much more prominent than the gaps in the front/under the lip - and it breaks the hood-to-bumper connection at the "correct" place, when comparing to a GTR. I'm gonna do this with mine this week, so stay tuned for pics!
×
×
  • Create New...