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  1. #1
    VXRed slonik's Avatar
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    Default Slon_workshop Astra tracktool build

    first of all, i'd like to introduce myself: my name is Misha, i'm from Russia and I'm a big fan of vauxhall cars.

    last few years i had to work mostly with bmw cars, but sometimes we've got some opels in our workshop.
    Years ago i've started in my house's garage, and these days we are moving to our new building (500sq meters+), where we already starts our own cnc mill (haas vf2ss), so finally we have our cars building space, cnc production and carbon fiber / Fiberglass production space under one roof in one building.
    so, most parts in this build will have my own design and production. some of them costs a lot (single copy production), but i like this project, so ready to make some tech support for it .


    this time i have some project of my mate's car - astra coupe turbo, which had z20let engine from factory, but we are changing it on z20net (saab b207r) and building NA engine on ITB's.
    main purpose of this build - make fast enough and very reliable car, which will quite cheap in using on trackdays and racing in time attack.

    i'll post build history not from the beginning, cause idea of engine swap was approved only after 6 month after purchasing the car .

    so, let's go.

    how our astra looks like these days

  2. #2
    VXRed slonik's Avatar
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    So, some of the first mods, were front subframe bushings - we were changed them on solid aluminum ones, finished in anodized red.


    subframe also was sandblasted and powder coated in gloss black.

    front arms, rear axle and and front anti roll bar got powerflex black series bushes.

    we were buying ST XTA coilovers kit (astra mk5 vxr) - which fits with some small modifications. front turret holes needs to be increased in diameter slightly.
    but not all going so smooth - on st springs, rear end sits really high (may be lightweighting gives those result), so we've bought shorter eibach ers linear springs (60nm) with helpers, and make new spacer rings, to fit springs correct between body and axle..
    to get maximum space for wider tyres on front, we also changed front springs on shorter ones (eibach ers 70nm, 140mm length). so after that coilover's lower nut stays higher then tyres, even on good lowering.

    our main target from the beginning was to fit 245 wide wheels (max allowed in our timeattack class) on good lowering without any rubbing, scratching etc.
    rear arches were rolled, on the front - only arch liners were cut in connection line with wings (and new fitting holes made)
    st xta colovers has oval holes on lower mounts and eccentric top mounts, so with max camber setting on the top we've get a lot space for our wheels.

    front:




    rear:


    overall view:

  3. #3
    VXRed slonik's Avatar
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    of course like every other race car, we'll prefer lightweighting the chassis to the lowest weight. but we are limited on one side with our championship rules, and on the other - our pocket (yep, it's not unlimited) .
    so, for the first time we were removed useless elements and reduce interior's weight.








    after that, interior floor was resprayed in body's color.

    that's not the best solution (black color have awful usability), but i think it's only temporary

    seats will changed on recaro profi spgs with 6 point harness.

  4. #4
    VXRed slonik's Avatar
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    When final decision was made, we've bought used z20net engine (saab b207r).




















    pistons and cylinders had minimal wear, so we choice to buy 86.25mm pistons and make minimal reboring.

    so, pistons were ordered from united states, forged diamond pistons, cr 12:1, teflon skirts coating.

    Engine, or, only, outer casing, were assembled, to use it for modeling, test fitted under the bonnet, new elements making etc.
    Last edited by slonik; 24th August 2017 at 12:49 AM.

  5. #5
    VXRed slonik's Avatar
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    individual throttle bodies.

    long story shot (a lot of night measurements of my bodies from the shelf), i've choose to use bmw s54 (m3 e46) oem individual throttle bodies.
    they have large 50mm butterflies, round inlet and oval outlet, which have very close dimensions to ecotec cylinder head channel, 52x34 on the bodies case, compared to 49x32 on ecotec head.
    this bodies have very usability design - all throttle bodies have individual cases, so you can change size between cylinders relatively simple.

    Interesting moments on this stage:
    1) gm head has perpendicular ports to the flange, bmw cylinder head not - they've made flange under different angle from vertical angle, so for the beautiful fitting and best air flow, we need to make adapter, which will compensate this difference.
    2) also we want to make intake horns aimed on the front grille - to make this, we will tilt throttle bodies on 10 degrees lower.
    3) we need to make smooth flow in reducing port window of adapter. to make this we will milling head's side of adapter little bit larger. at the end we will make minimal porting on inlet channels on our cylinder head - window will be wider on 1 mm.

    And some pics of our cnc milling of adapter from aircraft aluminum:











    intermediate result:


    and continuing milling








    adapter finished


    back side (cylinder head side)


    front side

  6. #6
    VXRed slonik's Avatar
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    test fitting






    side view (you can see tilt angle of the bodies)


    and front view


    all fits excellent, without any problems.

  7. #7
    VXRed slonik's Avatar
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    next step - all engine parts were on ultrasonic washing.

    few pics after arriving back:

    cylinder block




    cylinder head cover, oil pan and side cover


    cylinder head


    and with the bodies






    looks much better, but still not excellent

  8. #8
    VXRed slonik's Avatar
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    next stage - all this engine parts were on glass bead blasting.

    how they looked like after arriving back:

    cylinder head with cover




    cylinder block with pan






    cooling pipe

  9. #9
    VXRed blooded foxumall's Avatar
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    Some very high tech stuff there I must say and looks like a very good build I'll b watching this develop so keep coming with the updates

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