Individual throttle bodies build

Discussion in 'Technical' started by Rutger, Apr 30, 2013.

  1. Rutger

    Rutger New Member

    Hello everyone, my name is Rutger and I'm from the opposite side of the world, the Netherlands. I've been working on vg30's for years now and have a highly tuned vg30det in my S13 (not yet running). For this engine I build a manifold with individual throttle bodies, but the configuration doesn't fit the vg30dett. Recently I've been working on a vg30dett individual throttle body setup that would fit the stock bonnet. It was something I just wanted to build one day.

    Though on the other side of the world, I noticed there's quite some activity on this forum which is always handy should I need help or anyone needs mine. Building engines/manifolds is my hobby and I do not intend to start trading over here, if I did I would have to sign up as a trader.

    Anyway, back to what this topic is all about. I posted roughly the same story on as I've been a member for a long time there.

    I bought a set of 45mm bore SFS Jenvey ITB's and this winter I started working on it. Because of the little space underneath the bonnet and the masses of hoses, wires etc. I needed to have an actual 300zx to test fit. A friend offered me his 300zx, it's an old one with 234.000km on the clock (even original engine) and it needed a timing belt.

    The engine runs OK but idles not well. I found some damaged hoses but they didn't really change anything after fixing, eventually I noticed the engine is consuming oil badly and probably makes low compression on at least 1 cylinder. The valve lifters tick like hell and I'm in the process of doing something against that before the car goes to the dyno. Will be one of the last trips this engine will make.

    Now we all know how complicated the OEM manifold and fittings are. The valve covers aren't really helping either. I decided to remove the large raised sections and weld in a new plate. The baffles were fitted back in (no pics). The coils were modified to sit lower and welded/bolted to the exhaust valve covers. I also made a custom oil filler.


    I removed some material from the base of the OEM lower manifold for a cleaner fit, as you may know there's an edge increasing the diameter. The pipes were than welded upon. The exact angle etc. took long calculations and test fittings so I keep those to myself. The EGR bracket was removed, as it is not possible to make it work on an ITB engine.




    The flanges were welded on and the ITB's could be mounted.



    Modified injector covers.


    Further test fitting of the Jenvey velocity stacks and clearance underneath the hood. Clears no problem.


    An idle collection manifold was made underneath the manifold, all 8mm copper lines with brass fittings, no cheap hoses that can barely be used in such short bends.


    The complex plenums took 2 weeks to design and cut/weld.



    In order to link the cylinder banks I made a copy of the Jenvey OWK unit that pushes one wheel outside to line up with the other.




    An idle block was made for the AAC unit to attach to and links with the unit underneath the manifold.


    Eventually looks like this along with custom made hard pipes. Fuel lines customised and the AAC unit links the banks together along with the vacuum box underneath the manifold.



    With all parts fitted and the wiring harness modded to fit the engine fired up instantly. I did have trouble getting the idle down. I found out recently 3 welds in difficult spots cracked and need looking after. Other than that, I'm pretty happy with it.

    Vid of it running:

    Now this thing will be seeing the dyno once all the problems are sorted out. I don't have a date set but I'm hoping within 2 weeks. After that, the stock manifold will be tested in the same way to note the difference.

    Thanks for looking:br:
  2. rob260

    rob260 Administrator Staff Member

    Wow I admire your workmanship
  3. bRACKET

    bRACKET Do Right Dean

    Holy hell, I love it. Anything like this planned to fit a non turbo engine?
  4. _Robbo_

    _Robbo_ Active Member

    Thats awesome! Top work man. Would certainly sell alot if you went to market!
  5. Rutger

    Rutger New Member

    It is direct fit for the non-turbo engine, the only thing that would require changing is the 2 hardpipes from the intercooler pipes. They are now 50-70mm but for a high powered NA I'd go with 70mm all the way to the AFM and use some way of using 1 AFM per side for less restriction.

    I'm going to bed now and have a long day at work tomorrow so it will take almost a day for me respong again :)
  6. Shane001

    Shane001 Well-Known Member

    Wow, awesome work!
  7. ed300zx

    ed300zx Active Member

    Bloody Awesome.
  8. SIM300


    G'day Rutger,

    Very impressed by you workmanship. It would be interesting to see what difference ITB would make on a ig horsepower VG30DETT.

    I have a little dutch blood in me, but only know a handful of words. A lot of relatives still speak it. I love it, sounds like you have something stuck in your throat haha :D

  9. Jinxed

    Jinxed Moderator

    awesome, looks the goods and ill bet it performs when its all tested as well.....
  10. gmbrezzo

    gmbrezzo Moderator

    Very nicely done. Excellent craftmanship.
    Uneducated question: What is the difference in running individual throttle bodies over a single air flow control per bank.?
  11. beaver

    beaver southern zeds


    ITB's you've made Rutger are very impressive, be sure to let us know how they preform. Well done!:cool::zlove:
  12. bRACKET

    bRACKET Do Right Dean

    Can I ask what this is for?
  13. _Robbo_

    _Robbo_ Active Member

    An idle collection manifold perhaps? aha
    Oh Go do ya test.. ;)
  14. bRACKET

    bRACKET Do Right Dean

    Hah which does what exactly?
  15. rob260

    rob260 Administrator Staff Member

    Feeds the idle control motors?
  16. Chrispy

    Chrispy Pretentious Upstart

    Gets fed from the idle control valve. Allows the motor to idle. Should also feed the brake booster so you have brakes :p
  17. SRB-2NV


    Build me one for my zed, except with open trumpets. Then i can load it up with a direct port nitrous kit :)
  18. mungyz

    mungyz Well-Known Member

    Welcome to the forum and great work :)

    Always good to see more clever bastards coming on board :D

    TWIN TERROR Well-Known Member

    Love the work mate. Not just a cut and shut but real quality work. I would bet you would be able to sell a few. Would love to see dyno results compared to stock.
    Cheers Dave
  20. tassuperkart

    tassuperkart Its a lie I tell you!

    Rutger does his stuff with plenty of thought and importantly, IMAGINATION!
    It's this kind of imagination and can-do scratch building nous that I admire so much.
    Makes "cheque-book" mods seem so meh.

    Performance gains, or not, gets my salute!!


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