Toyotec's how to make your MK3 16v breathe on a budget. Part 2 added 14-12-09

Discussion in '16-valve' started by Toyotec, Sep 13, 2009.

  1. mec82 Forum Member

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    Niek5291 - that looks like a very healthy engine! Are there any other mods other than head, cams and airbox? Looks like the torque is really hanging on high up, are you using megasquirt or other mappable EMS for the fuelling?
     
  2. Niek5291 Forum Member

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    Yeah, I think it's quite healthy, but now I have a ticking lifter... So the head has to be opened again.


    Here a list of the mods:
    - Standard bottom end
    - CNC ported and polished head
    - Tapered valve guides
    - New valves + stronger springs
    - Schrick 268/268, 11,5mm lift max.
    - Catcams adjustable cam pulley
    - Polished the throttle body a bit
    - 4-2-1 stainless steel exhaust manifold
    - 200 cells catalyst
    - 60mm stainless steel exhaust, with 2 Simons free flow silencers


    The engine still runs on Digifant 3.2. It's remapped on the dyno, at JD Engineering in The Netherlands. It was remapped before, only with the 4-2-1 exhaust manifold, 200 cells cat and cat-back system, and then it produced 174bhp, 153whp and 204Nm of torque. I lost a bit of torque now in the lower rpm area, but above the 4.500rpm it feels much stronger than before.
     
  3. mec82 Forum Member

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    thanks, good numbers with a catalyst as well!

    I'm surprised that it holds onto the torque so well: >195Nm @ 7000rpm. Never seem a torque curve like that on a 16v with plenum intake before, would be interested to hear Toyotecs thoughts?

    Did you have to modify the head, valve guides/stem seals for those cams with 11.5mm lift?
     
  4. Niek5291 Forum Member

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    I took those cams because of the high lift. High lift gives a bit more torque, in general :p, and i still wanted a decent idle and a bit power in the lower rpm area.

    I didn't have to do any mods to the head, before I could install the cams. The guides are new, and tapered, but the same length.

    My tuner said this was quite the maximum with an original plenum. 200bhp is possible ofcourse, but for more power you'll need to install a shorter intake or itb's.
     
  5. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    You are not allowed to surpass drive by noise limits on production vehicles. The tube in these older airboxes help to meet this requirement for noise and still meet the targeted/homologated power and torque levels. When you modify the engine to inhale more air than stock, thus tube causes a nasty pressure drop post filter/pre engine.
     
  6. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    My Thoughts are:

    The OE airbox increases 'launch' torque but restricts top end airflow as shown in the back to back tests w and w/o the stock air filter.

    Actual dyno numbers and more importantly the plot shapes, differ to what I post on here for the same engine types. Looking at Niek5291's plot with a Plenum, 4-2-1 exhaust manifold, a cat and the factory airbox, I could see some what I term 'skewing up' on torque at 5800rpm, where as on a similarly modified engine tested at GS I would expect torque to be dropping off around the same point same engine test. This means on a test like that 166bhp@6100rpm or so, 149lbft@4800rpm and about 118lbft@6600rpm. I expect a late kick up of torque at just short of 6K with the headwork, cams and matching calibration. However with the skewing effect added to this, the numbers and the shapes would be amplified upwards of what I would generally display on this forum.

    This car has definitely improved though and the back to backs are repeatable in terms of percentage changes. Look forward to what will happen when the airbox is modified and retested. I would suggest running tests with the airbox/filter as it is and swapping with a modified airbox w/the same panel filter and test back to back, to cater for any ambient condition on the test date.
     
    Last edited: Sep 20, 2013
  7. Niek5291 Forum Member

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    The car's performance really has been improved. It's very fun to drive. I'm also looking forward to what will happen, when I fit a modified airbox. This is a project for later on this year. Now I'm busy with school again. Another improvement will be a shorter gearbox. The engine is very agile after 5.000rpms, but the CDA-box really is a bit too long, especially the third gear. I'm thinking about using an end reduction from a 2.0 8V, Passat B3. Thanks for your opinion!
     
  8. SIX

    SiX New Member

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    im sorry, pretty new here, can you explain?
     
  9. Niek5291 Forum Member

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    I have been searching for a decent ABF filter box for quite a while, but recently Ive found one! With the ideas of this topic, I started modifying. I drew a trumpet in Inventor and handed it over to my mate. With the aid of him, he offered me a 3D-printed trumpet! It looked quite awesome, but I smoothed it a bit more with fine grinding paper.

    Also modded the box inside. I deleted the valve in the bottom part, blocked off the hole at the back (with a cap of a Castrol oil bottle [:$], and deleted some ribs. The upper trumpet I left standard.

    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]


    It's not louder than it was before (already quite noisy with only one silencer and one flame arrestor), but in the higher rev's you can surely feel it breathes a lot better. It has more 'air' and feels more vivid. My panel filter was also quite dirty, so I gave it a clean as well.
     
  10. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    Glad to see this thread is still being used!

    Like the 3d bell mouth!
     
  11. Niek5291 Forum Member

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    Yeah, searched a lot in this thread, because this kind of 'tuning' makes you creative and gives advantages in a cheap way :p.

    Also great to see a design from computer in real life. The printing of the little ******* took about 10 hours :).
     
  12. Millhausen

    Millhausen Forum Member

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    Reviving a very old thread. I plan to do this mod in the next couple of weeks. Collecting parts for when the car comes out of the paint shop.

    Because the car is not with me though, I have no idea what size belmouth to go for. I'm assuming a 4"?

    Any help appreciated!
     
  13. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    That sounds ok to me.

    As long as it is bigger than the supply to the engine air duct.
     
  14. Muuu New Member

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    hi,
    i have a abf in my golf mk1 and have install golf mk2 GTD box airfilter with k&n filter.
    [​IMG]
    *this pic it's another user in forum

    at this momen i have 162hp 201nm testing in dyno my friend.

    ECU remap, magnecor 8mm, exhaust 60mm, iridium race
     
  15. arniks8 New Member

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    Hello guys,

    I have access to a 3d printer, so I figured i could just make my own trumpets. I'm wondering if the trumpet design would have significant impact on flow(as in not screwing it up). For now the upper part looks like this

    [​IMG]
    [​IMG]

    Would something like this be acceptable or should it be redesigned?
     
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  16. RBPE Forum Member

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    Excuse the poor 2D tests, was many moons ago and you get all the figures so the pics were largely irrelevant!

    If you look at this old tdi-esque data and sort of assume the tract/inlet length's are indicative of something like a torque curve, then you can see the variances that occur;
    [​IMG]TDIMODELOVERLAYINLMANI_zps01c9a7cf by Rick B, on Flickr

    Especially at the 1st runner, you can see speed/pressure variances occuring due to the smoothness of the taper to (any) port, the transition of smooth/laminar air to turbulent;
    [​IMG]vr6inletmani2_zps6179f521 by Rick B, on Flickr

    Then finally there's the same air speed through orifices of different dimensions;
    [​IMG]65mmv85mmthrottlebody by Rick B, on Flickr

    In simple terms then - you should be mindful of the difference in air speeds of an engines input - the peak torque/runner lengths and the influence - more your runner/inlet manifold lengths and peak torque than your bell-mouth design. Then in terms of your bell-mouth design, in my experience, the most open/smoothest transition as you squeeze the air into a narrower hole is best - packaging constraints limit you here but if you can make this smoother/wider in your design then go for it (I also did some plenum design changes at the time, the central inlet, like TFSI mani's, was by far the best for equal dissipation of air to ports). Then you need to think about things like ultimate gas flow v's things like heat - energy efficiency basically - having measured an ABF TB at about 450hp until too turbulent. So you can get better responses, actions at low air speeds with smaller orifices which in turn can be either banes of benefits depending on what you're aiming for!

    Hope this helps?
     
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  17. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    That could be interesting for all MK3 airboxes!
     
  18. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    I am not sure what is the relevance to the test I did on MK3 Golf AIR BOXES as it related to the fitted ABF engine?

    As far as I am concerned a conclusion was drawn on the basis of that experiment that that was that.

    I am up if someone else wanted to do their own and clearly state their intent and conclusions though.
     
  19. arniks8 New Member

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    I'm making it for seat ibiza(6k) airbox, but I could make something like that for mk3 airbox too and drop the file in here.

    Original trumpet has a very small lip(don't know the term). Is it because of the intake sound requirements or since this is just an airbox, it doesn't affect flow that much?

    [​IMG] [​IMG]

    So I based on RBPE's post, I made another trumpet that is longer and smoother, but I guess I just have to get a software to compare the flow between several designs and make a conclusion based on that.

    [​IMG] [​IMG]
     
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  20. RBPE Forum Member

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    Your original design was probably better looking at the taper and for an airbox, if you're going to add length, make the bell-mouth wider, you've got enough length too with the oem set up - the torque changes pic and certain aspects mentioned would probably suit things like bike carbs/a more direct intake system;
    [​IMG]elo by Rick B, on Flickr

    If you make it wide enough you're going to funnel the air into it and reduce the pressure build up/turbulence that would result as the air misses the bellmouth and hits the sides of the airbox and goes off in all directions. Sorry don't have any old data with that but you can see such build ups in this little fin test I did to get an idea;
    [​IMG]ividedpipe_zps280a6ab0 by Rick B, on Flickr
     
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