Engine & Gearbox Inlet manifold swap on a D14A4/Z1/Z2 for one off D16Z6/Y8, D15B or D15B7 (guide)

Discussion in 'Honda D-Series' started by mugen-b16sol, Monday 26th Dec, 2016.

  1. mugen-b16sol Valued Contributor ★ ★ ★ ☆ ☆

    Thought I would write a quick guide on how this swap goes well at least from my perspective having done it recently.

    So why do it? Throttle response is a bit better and it pulls through the whole rev range better, BHP gains are probably minimal but then again that depends on what other supporting mods you have done and if you have converted to obd1 or not also choice of induction kits is better with a sidedraught inlet manifold rather than the downdraught version the D14 has as standard.

    Stuff you need :
    Inlet manifold complete with all sensors, fuel rail and TB off a sidedraught inlet manifold (D16Z6/Y8 or a D15B/B7)
    Extra hoses for coolant and PCV breather canister plus hoses clips
    Inlet and TB gaskets - good idea to have these new as back up as generally when taking the inlet/TB off the originals tear.

    What next?:

    This part is pretty self explanatory take the original inlet off with all hoses etc then you will need to swap a few things over to the new inlet as follows -

    D14 TB complete but use the throttle pulley off the D15/16 TB
    Change the D14 injectors to the D15/16 fuel rail

    Ok done the above? right next you'll need to attach 2 hoses to the back of the engine and block one take off on the new inlet itself.


    On the water pipe going across the back of the engine from the water pump to thermostat you will have a small take off from this you will need a small pipe as above going to the D14 RACV, the small take off from the inlet itself also pictured above goes to the other take off on the RACV and below is the one you need to block off on the inlet itself.


    Next you will need a pipe long enough to go from the PCV canister below to the bigger take off on the front of the inlet


    Done the above? Ok you should be ready to put the new inlet back on and attach all relevant hoses now, you may need a mate to help support the inlet whilst you do the nuts up on the underside the middle one is a bit of a :tut: to get to.

    Things to note I would take the standard inlet support bar off too as this is too short and not really needed, also there will be one take off left on the back of the inlet which I plumbed into the EVAP valve. Otherwise that's about it the IAT sensor put that into the intake tube of your new induction kit or if you are running a standard airbox setup off the new inlet then into the intake pipe of that will be fine too, standard throttle cable can be retained too it'll be a bit long but you'll be able to route it to suite quite easily.

    Should look something like this when done


    Can't think of much more to cover but if I've missed something out let me know and I'll make an edit, hopefully this will be of some use as when researching a month or so back I found a lot of people still asking about it for a cheap £50 mod can't go wrong really.
    legend-ary, K24 CL9 GUY and RogerH69 like this.
  2. RogerH69 Premium Member Club Supporter

    South Africa Roger Oxford, UK
  3. K24 CL9 GUY Club Veteran ★ ★ ★ ★ ★

    United Kingdom Guy Gloucester
    Nice work :Smile:
  4. elias2047 Junior Member ☆ ☆ ☆ ☆ ☆

    Clean! Defo doing this next