D15B7 - Z6 Mini-Me conversion

Discussion in '5th Generation (1992-1995)' started by AshMitchard, Saturday 15th Jun, 2013.

  1. AshMitchard Junior Member ☆ ☆ ☆ ☆ ☆

    Hey to all, haven't been on here for a very long time! only just got my computer up and running again haha...

    Right then, after months of preparation and rebuilding as and when i could and building up my parts collection to do so, i have done my mini-me conversion, head has been on for 40 miles so far and is still running in, I've given it one bootful to check VTEC engages and it does, otherwise i have been just casually driving running the head in as i cleaned up the head, polished the exhaust ports and lapped the valves back in with cleansed chambers. 

    My build consists of a D15B7 engine

    D16z6 :-



    -throttle body


    -timing belt

    -P28 ECU

    -fuel rail, injectors and pressure regulator

    All the stuff was taken off a running car from what i am told by a mate. The bit that annoys me most about all of this swap is a very long flat spot which lacks power from 2.5K-3K and gives a small amount of smoke once out of the flat spot. Now then, my first 20 or so miles (I didn't know) my breather in the cam cover was blocked by factory casting of which i have knocked out and it breathes now, am wondering if the oil that has been pressured past seals due to pressure in the cam cover has leaked onto the piston causing the burning oil and flat spot.

    I've put a bottle of REDEXE into the petrol tank and filled up the tank and i'm now 1/8th of the way from full tank now and the smoke is getting less and less, as is the flat spot, just asking if there are any common problems that would cause the flat spot? possibly the O2 sensor being a bit bunged up perhaps?

    thanks in advance to replies :Smile: all help is appreciated so so much! lol
  2. Dan Club Veteran ★ ★ ★ ★ ★

    United Kingdom Dan Oldbury
    Are you sure its not just the fact that its a D lump, and doesnt really have that much power or kick, which makes it feel like a flat spot? I think the D16z6 engine (or a mini me) are very disappointingly slow engines in standard form.

    To whichever mod put the VTEC word filter in too, you are a legend! 
  3. AshMitchard Junior Member ☆ ☆ ☆ ☆ ☆

    LOL at the VTEC word filter ;-)

    I know its a flat spot as the power bogs down and then picks up straight after, exact same thing happened in my classic mini before i tuned up my high spec engine in that too. Could it be the Ignition Timing?
  4. longchris Valued Contributor ★ ★ ★ ☆ ☆

  5. ben bury Club Veteran ★ ★ ★ ★ ★

    Mine had this flat spot. I thought it was there to save fuel during holding low revs on a run.
  6. Smiley Club Veteran ★ ★ ★ ★ ★

    Flat spot will be caused by two things.

    You have no adjustable cam gear, so the timing will be out.

    A p28 is mapped for a d16z6, not a minime. Youll need it mapping to get the most out if your new set up.