Individual throttle bodies build

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



    Awesome setup .

  2. ABZ300

    ABZ300 G

    WOW, just WOW

    Enough said :)

  3. Rutger

    Rutger New Member

    Thanks everyone for the compliments and the warm welcoming! I'll try to answer the questions.

    Uneducated question: What is the difference in running individual throttle bodies over a single air flow control per bank.?

    -You mean running 2 TB's instead of 6? Well the direct advantage of using a separate TB per cylinder is that it allows for faster engine response. The closer to the valves the better. Motorcycles almost always have ITB's because the response is critical to handling. ITB's pose a restriction within the intake but that can be used for good, the way in which the valve moves dictates the way in which air flows inside the port. In my setup, like on every serious race car I ever saw, the butterfly valve moves towards the lower portion of the port. Because the fuel is injected to that same side, the angled stance of the butterfly valve dictates the air to move along this side and adhere to the lower side of the port. It takes the fuel along improving mixing. If this setup is not used, and the butterfly valve opens 'sideways' within the port the engine can easily misfire.

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

    -I could make that easily. A friend has a 48mm Jenvey ITB kit he's no longer going to use, along with some 48mm bends. I could build upon them, may not even require mods to the valve covers just the coils would be a problem. 48mm ID is kinda big for a turbo engine but would do no harm on a seriously build NA with long duration/high lift cams.

    '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!!'

    -Yeah I needed to think out of the box for this one. Hold the parts in your hand, look at how it could or must fit. Put it away and do the same 3 weeks later. After a year repeating that everything finds a place.

    People told me the valve covers could not be welded, they would warp and crack. Well, I cut them, welded them without cracking or warping and now they're fitted they haven't given a sweat of oil. Another problem with the fuel rail. The housings of the TB's interfered with the injector caps and the bolts holding them. So I cut a small part out of the TB's housing, and replaced the philips bolts with countersunk allen bolts. It works.

    I don't understand noone did this before me. The other 2 setups (the nitrous NA one and the blue one with the fake carbon plenum) are far less complicated than mine and the blue one don't fit the stock bonnet.
  4. tassuperkart

    tassuperkart Its a lie I tell you!

    I think the answer to this is reasonably clear.

    Firstly, very few have the necessary nouse and imagination to begin with.
    Not to mention having the necessary facilities, machinery, equipment, time and knowledge to fabricate.

    ITB's, even in a straight configuration are complicated and fiddly. Not to mention expensive. They require a lot of sorting out with regards to linkages and balance especially when not valanced together.

    Next, the performance gains from the stock setup v's this ITB setup, IMHO will be incremental at best and indeed, the shortening of the inlet throats ahead of the valves will shift any gains in the ordinary everyday driving zone from accoustic tuning to well above a useful rpm range.
    This is not to say the engine will falter. half an extra psi in boot will nicely cover it, but subjective dyno testing will certainly show a measureable loss in low to midrange power in an NA for a given state of tune.
    Ignoring obvious production issues, this is why the stock system is designed as it is. Promote low and midrange driveability at the small expense of top end.
    Apart from very low down around idle, (which doesnt really matter anyway in this kind of instance) the stock intake system does not lack any throttle response worth noting.

    When you balance up the advantages of ITB's against the obvious, (and not so obvious) less than positive issues mentioned above, its no wonder very few, if any fabricators will devote the time, money and effort required. As rutger says himself, literally hundreds of hours have gone into the production of this marvelous bit of handcrafting!
    The stock manifold may want for some subtle massaging to better optimise it across the board (Mungyz's modded inlet rails for a start) but its not too bad a bit of clobber when the sums are actually done given the monetary and practical restraints of a mass produced passenger car.
    Its well proven NOT to be much of a hindrance in even stupidly high rpm and boosted performance so again, IMHO there is really not sufficient incentive to redesign.

    I love your work Rutger and even if this artwork results in an across the board LOSS of HP and response, its worth the effort for the exercise alone!!

    Drive on bravely into the world Dutchman!!!!

  5. gmbrezzo

    gmbrezzo Moderator

    Thanks for the informed responce. Helps me understand more.
    So in short is improves responce and more controlled fuel disipation.
    Doesn't actually improve HP other than more efficent fuel vapour transport.
  6. SuperZ

    SuperZ Resident Z lunatic

    Hey Rutger welcome to aus300

    Some GREAT WORK THERE MATE - When are you doing mine!

    PM me with the dates that work for you

    10 out of 10 for effort and the final mark is looking good so far


    UNIQUE ZED Zed Racing World

    Very trick. I would offer you a job.
  8. nick300zxtt

    nick300zxtt Member

    Love your work, pure Zed porn and maybe one day I may get around to replicating this :)
  9. Rutger

    Rutger New Member

    Thanks for the compliments everyone :)
    I was hoping to be able to update this sooner, but I had some bad luck several times. First 2 welds showed small leaks that I welded and fixed, along with the replacement of several noisy lifters. Next, a couple of injector seals cracked and created a vacuum leak. Fixed them again but last wednesday after I built it up the 5th cylinder injector created a fuel fountain after it's seal blew up. Glad it didn't catch on fire!

    Fixed everything so today was the day it should be back up again. Couldn't get it started but a set of jumper cables from a running car helped. Engine then ran like it did with the original manifold and after adjusting the idle I went for a test drive. But once the engine was up to operating temperature it started hesitating and eventually passed out. Couldn't get it to run normal anymore, it was behaving as if it getting almost no fuel though I'm sure it has enough in the tank.
    My brother's GTI-r once had the same problem when the fuel pump died. And I don't remember hearing it when we were cranking the engine to get it back up...

    So tomorrow I'll be checking the pump out and hopefully this car can see the dyno soon. There's also one thing you people may be able to help me out with. This car is still fitted with the old style power transistor, it was replaced back in 2001. But they replaced it with that same old style PTU! Now I was pushing against the PTU harness when the engine was idling at 900rpm and the engine behaved different as I pushed the harness. It also runs like it skips 1-2 cylinders every cycle, but unplugging the ignition coils one by one shows no specific problem for any cylinder.

    Could the old style PTU along with the fuel pump be the cause of the engine issues I'm running into right now? I'm quite confident the ITB setup has nothing to do with it. The car is now working against me. Thanks in advance:br:

  10. SIM300


    Series 1 PTU's are known to play up when they get hot, then operate normally once they've cooled down. If you suspect fuel starvation, it could be the FPCU (another common problem).
  11. Chrispy

    Chrispy Pretentious Upstart

    Often the connections on the PTU can corrode. Pull the plugs off and clean the contacts.

    I always recommend a new PTU and engine harness though.
  12. Rutger

    Rutger New Member

    I've been having a load of trouble with the car, 2 times injector seals failed, next, the pump voltage control unit failed along with the FPR and PTU. Now the car is finally back up, yet after another FPR failed. Eventually fitted a brand new aeromotive FPR and it runs and pulls strong, especially for such an old engine. Taking the car to a garage on tuesday for it's yearly required road approval test/check over. The car can be driven legally to the dyno that way.

    The guys at the dyno told me a dyno shoot out can be done the same day if I call them early in the morning, and since I have wednesday off that may be the big day. It's this shop they build a 1250hp R32 so they should be sorta capable of knowing what to do with this.

    I thought about making a small vid of the how the car's running now but if the cops see me on the street with it I'll be in big trouble. So other than a few full throttle pulls on a straight end close to my home in the dark I'm taking no chances.
  13. strange zed

    strange zed Member

    that thing looks the part. looks alot less crowded then the oem plenum
  14. Shane001

    Shane001 Well-Known Member

    Are you going to do back to back runs on the dyno with the stock plenum and your plenum?
  15. Anti

    Anti 14.7 x 14.7 = 44.1

    This is some seriously awesome work. Really enjoying following this thread, please don't leave any detail or update out!

    You've obviously thought about producing these, I assume it's financially unfeasible?

    It's a shame your test car is such a POS. Would be much cooler seeing this on a properly maintained/modded Z32. The motors in these cars are very reliable, it's just everything attached to them that has issues...
  16. nick300zxtt

    nick300zxtt Member

    Can't wait for further updates :)
  17. discus177

    discus177 New Member

    So, what's the go with your timing belt in the picture...
  18. Rutger

    Rutger New Member

    Yes I am. After the run on the dyno the car will be brought back to the stock manifold. Due to the 'poor' condition of this engine, the results from a dyno with this manifold can't be honestly compared to the stock result from a different healthy 300zx. It wouldn't even surprise me if the car is 30hp down on stock power with the stock manifold.
  19. Rutger

    Rutger New Member

    I'll keep it as detailed as possible. I could write dozens of pages on how I build every part of it, it's extremely complicated. I know the car sucks, the car belongs to a friend and he doesn't want to spend any money on it other than the necessary stuff to keep it rolling.

    I've already calculated what it's gonna cost to build, send me a PM if you want to know as it may appear as trading when I start putting prices on stuff openly on the forum.
  20. Rutger

    Rutger New Member

    Pic was taken before the belt was re-fitted when I just fixed an injector seal leak.

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