D2 380mm brake kit problem - hard shacking

Discussion in 'Evolution IX - I - Suspension' started by andreitentean, Dec 19, 2010.

  1. andreitentean

    andreitentean New Member

    Hello my dear colleagues.

    As I found myself always looking
    for answers on this community for my problems and questions about which is the
    best mod for my car, what the result for that other people got for the same mod
    that I am willing to make, results made possible only by taking chances and spending
    time and money of their own pockets, it thing it is time to share back my
    experience with you guys. My bad experience, so you could have a chance not to
    go and make the same mistakes as I did buying BAD QUALITY products.

    My car is an Mit EVO9 (other cars
    that I own : STI03, Civic TypeR, BMW E30 M3, Celica CS, Audi S3 1.8T, Dacia
    Logan CUP-race car) and some of my mods are : FP Green turbo, Deatschwerks
    injectors 750, ARC intake box and titanium intake pipe, HKS cams, HKS
    coilovers, Ralliart 18†wheels, and some other small parts.

    Recently I wanted to improve the
    braking on my car and beside AP Racing 6pot 362mm kit (which I have on my STI
    for 3 years-12000km and I love them) and BREMBO GT 6pot 355mm kit I was also
    considering the Taiwan company called D2 which makes a massive 380mm 8 piston
    kit for the EVO.

    2 things made me to make the
    wrong decision, the bigger diameter of the rotors, 380mm versus second best AP
    Racing 362mm, and the cheaper price compared to the AP and the Brembo kits, so
    I got the D2 brake kit. – STUPID MOVE

    I know that this topic is not
    about me, but a short introduction will show people that I really don’t thing
    that the problems with the brakes comes from bad installing or abuse : I run in
    my country a tuning company called Superformance, dealer of SKN Tuning Gmbh
    since 2007, with some rally and hill climb activity in the last years : tech
    support in 2009 for hill climb national champion open category in an EVO6, and
    my personal race history running with 1.6 Dacia Logan : 2008 FIA GT Logan Cup
    first race winner and after disqualified due to engine modifications, second
    race second place, 2009 hill climb champion at 1.6 category .

    My “raceâ€car : http://bloganul.blogspot.com/2010/11/loganul-skn-lui-andrei-tentean-de.html

    About the FIA GT event: http://prorally.ro/net/index.php?option=com_content&task=view&id=2964&Itemid=31

    After installing the D2 380mm
    front brake kit I have made the brake in myself in a period of 450-500 km.

    After the brake in was over I
    started to use the brakes with moderate to full pedal pressure in different
    conditions to see what I have paid for, first results where not impressive ,
    not bad but somehow different than what I was expecting . Brake pedal travel was bigger/longer than
    before and with a somehow unnatural behavior, first part of pedal push was
    return less braking than expected and the next part was locking the tires
    pretty easy. I suppose this is normal, the pedal travel should be longer
    because of the increased fluid than goes in the bigger than stock caliper and
    tires look is due to the excessive 380mm size ! – So first lesson : for the
    street using normal street tires you do not need 380mm discs to stop an EVO.

    The biggest problem came in the
    next 1500 km (all on the street, should have happened earlier on a track day or
    weekend), shacking under breaking become more and more obvious to a point the
    is nor pleasant or safe to drive the car anymore and stopping at a stop light the car will stop
    itself after releasing the brake pedal
    at 1 or 2 km/h and this means only one thing : pads are still touching(or even
    pushing) against the disc even when brake pressure is not applied !!

    After checking the wheel and tire
    balancing TWICE (and i do have the receipts to prove it) which was perfect
    exactly as I imagined because I run on Ralliart RAYS forged 18â€wheels and I
    always look after them, I put the car in the garage and make the next
    measurements which I also filmed to send to D2 but for no good because the
    answer was fast and clear – it is my fault, no warranty on brake discs.

    I tried to explain that heat
    damage to the discs came from heat build up during roll on from the faulty
    calipers which do not release the pads from touching the disc but the answer
    was still the same – no warranty for the brake discs !!! STUPID ME FOR BUYING
    D2 !!

    Same tests for both sides, left
    and right.

    You can see in the movies that
    the calipers are expanding under pedal pressure, this is bad manly for the
    performance orientated customer how will want some feedback from the brake
    pedal ! Pressure is wasted in the bad design and probably bad material caliper
    instead of going to the pistons and so on to the pads !

    LEFT D2 caliper expanding under pressure


    RIGHT D2 caliper expanding under pressure


    Here you can see that using a
    dynamometric wrench we could approximate the effort needed to turn ONLY the
    disc – 30 Nm to a side and 45 Nm to the other !!! This is EXTREME ! This D2
    people are wasting our hard earned horsepower !!

    LEFT D2 rotor 45Nm to rotate


    RIGHT D2 rotor 30Nm to rotate


    And here you can see and imagine
    the shacking under braking !! discs are fucked up in less than 2000km, that is
    less than 1250 miles !!

    LEFT D2 rotor moving left and


    RIGHT D2 rotor moving left and


    LEFT D2 rotor moving up and down


    RIGHT D2 rotor moving up and down


    So maybe I am unfortunate, or
    maybe I really do not know how to brake or use a set of brakes, or even both,
    but I will not come close to the D2 ever again. Anybody can make mistakes but
    not to take responsibility for your product is not Ok. Hope this helps.

  2. lancer2quick

    lancer2quick Well-Known Member

    Welcome to LT. I'm not the greatest mechanic in the world, but I may be able to help. Since you are into racing, I'm going to assume that you have checked every brake line for small cracks and have checked all the connections for leaks. If you are using the OEM master cylinder, the size (bore) may provide the initial clamp force but releases because of the total capacity may not be enough to maintain consistent clamp force.

    If you are using an aftermarket performance master cylinder, it may be an issue with the o-rings...causing an internal leak. Since master cylinders are sealed, the fluid wouldn't leak out until the main seal fails. If this happens, there will be a pop and you will lose all braking force.

    Like I said, you have probably thought of this already, but that's what I know...
  3. andreitentean

    andreitentean New Member

    no, I didn't check that until now.
    Thank you for the suggestion.
    It seems ok, it is the oem brake cylinder.