Jump to content
SAU Community

Rb25Det Flat Spot In R31

ianga

By ianga,
in Engines & Forced Induction

 Share

Recommended Posts

ianga Apprentice

ianga

Posted
Posted

Hello Guy i have a rb25det in my r31 and i have a flat spot between 4000 - 5500 rpm then it picks right back up again. now i have done a search but couldnt find what i wanted

car is running 11psi

plugs have been changed and regapped to suit more boost.

has a little miss at idle and sits around 500-600 but once around 1000rpm its fine.

stock ecu

checked timing

i am going to rev zone and putting it on a dyno in a few weeks not much they can do with a stock ecu tho.

any help on this problem would be great

Cheers Adam

Link to comment
Share on other sites
Dobz Experienced

Dobz

Posted
Posted (edited)

Try winding back the boost and see if that changes anything.

From what I inderstand rb25 ecu's can be a bit touchy when winding the boost up.

Edited by Dobz
Link to comment
Share on other sites
GTScotT Grand Master

GTScotT

Posted
Posted

The boost is the first thing to check, put that back to 8 or 9 as stated.

The other thing is to make sure ur VCT is working.. A search will bring up a few threads about testing VCT.

Link to comment
Share on other sites
Room42 Proficient

Room42

Posted
Posted

The problem is the stock ecu. Get a power fc or better still a mafless ecu and put it in. Dont worry about taking it to the dyno yet, its a waste of money. Put that cash toward your new computer. It will feel like a new car once the computer is in and tuned. Your car will have about 150rwkw give or take.

Link to comment
Share on other sites
Room42 Proficient

Room42

Posted
Posted

i turned the boost down to 9psi, cleaned the acc valve. idles smooth as now but still have a little flat spot.

Yeah mate they all do it. You cant do anything about it till the ecu is swapped over or piggybacked.

Link to comment
Share on other sites

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

    • GTSBoy
      ENR34 - Leaking Transfer Case

      By GTSBoy · Posted

      The autos suck. Anyone with an auto wants to go manual. Also, the one thing you don't really need to change is the dash. You don't really need to know (on the dash) what gear position you have selected. What you do have to change is the tailshaft, a bunch of wiring, probably gearbox crossmember, a bunch of fiddly shit like the spigot bearing in the back end of the crank, find a flex plate and a converter, etc. A whole lot of pain. Most of those autos have been rightfully put into metal recycling bins, so they're not exactly easy to find either.
    • AdiR34
      ENR34 - Leaking Transfer Case

      By AdiR34 · Posted

      Appreciate it man, gives me hope based on my Google searches on availability of GTR parts.  When you say I'm "not going to," is this in the vein of "who on earth would want auto," or more "it's impossible?" Not trying to be rude, truly don't understand haha. I know, it'd be a madman move to go manny to auto, but if it IS my only option, I'd be curious on the lift.
    • GTSBoy
      MLR's Bogan cruise ship

      By GTSBoy · Posted

      Where's the other half?
    • GTSBoy
      My R32 GTST From Canada

      By GTSBoy · Posted

      Shit's f**ked. Looks like there might be a crack to the intake valve seat on the opposite side of the chamber also. Defo pull the whole thing down. Nothing good can come from just doing the head on a motor with comp figures that low anyway. You'll hate yourself less in the long run.
    • CanadianGuy
      My R32 GTST From Canada

      By CanadianGuy · Posted

      Well hit the first larger snag in the build!    Car wasn’t running 100% right even before I took it for a drive, starting slow and felt like a bit of a miss so compression tested it once I got it into the garage and on stands for the winter.   That would do it…   Got to tearing everything out and was greeted with this   Seat looks a little mangled but somehow the cylinder is fine   Will check the turbine next wonder if the piece made its way in there and chewed up some fins.    Once I survey the extent of the head damage I’m going to have to make a decision. Cylinder 4 is kind of low anyway so might not be a bad idea to take a peek at the bottom end while I’m already in it
×
×
  • Create New...