1st Gen R53 Cooper S Most liked posts in thread: 78mm bore job

  1. Jan

    Jan Well-Known Member
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    #2 Jan, Jul 9, 2014
    it all depends on whether you have core shift in the block and how much boost are you going to run through it. Why not just run 77.5mm and be sure you don't have issues? You are NOT going to see a hp difference worth risking the integrity of the block.
     
  2. Jan

    Jan Well-Known Member
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    #14 Jan, Jul 12, 2014
    someone is blowing cherry flavored smoke up your backside..............
     
  3. Dave.0

    Dave.0 Helix & RMW Powered
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    #4 Dave.0, Jul 9, 2014
    No boom and Boom

    Bigger is not always better. Ever race a v6 or v8 on a twisty road. :devil::lol:
     
  4. CarlB

    CarlB Active Member

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    #6 CarlB, Jul 11, 2014
    You will not get anything close to 20 HP from the 1 MM over bore. What you will probably get is weak cylinders that will not seal the rings. Modern engines are not made with thick cylinders. Below is a chart that shows the engine displacement for the different bores. If you assume your engine makes 200 HP the affect of increasing your displacement by 41 CC is 5 HP. That assumes everything scales up. Bore Displacement Difference Percent Increase Power Increase
    77 1598.157 200
    77.5 1618.980 20.823 1.30294% 2.605876644
    78 1639.937 41.780 2.61426% 5.228522604
    Excel does not paste well but the percentage increase in displacement is 2.6 percent.
     
  5. Dave.0

    Dave.0 Helix & RMW Powered
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    #8 Dave.0, Jul 11, 2014
    Skip the plug wires and any non-OEM Coil as the OEM ones are food up to 400 hp.

    A 15% pulley, intake, a Big Valve head like the RMW head will be the keys to the power you want to make. Once you get that together contact Jan above for a custom tune with larger 450 or 550 injectors.

    Also a quality header will also help also. I would recommend you ask Jan / RMW about what he has to offer and create a build plan.

    The only Intercooler worth anything is the GP intercooler made by MINI.

    Jan / RMW has been building high quality fast and high HP MINI's for a long time and he was also the one that replied to your first post.

    Building up a MINI is not a cheap project so why not get the best for your MINI first and do the build once and right the first time. Learning on the web is free having your car fail to learn a lesson gets costly. :idea:

    Good luck with your MINI build and post up some pictures of your car. :Thumbsup:
     
  6. Nathan

    Nathan Founder

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    #10 Nathan, Jul 12, 2014
    I do understand the Blue Theme, been there, done that. Learned the hoses don't really hold up that well. Back to OEM.
     
  7. TheModFather

    TheModFather Well-Known Member

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    #13 TheModFather, Jul 12, 2014
    LOL!

    Where can I get one of those? :p
     
  8. MCS02

    MCS02 Moderator
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    #11 MCS02, Jul 12, 2014
    Don't get the silicone intercooler hose! You'll be sorry, ask how I / we know. They look prity but don't seal well.
     
  9. DJBishopNYC

    DJBishopNYC Member

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    #3 DJBishopNYC, Jul 9, 2014
    Well I was told bumping up 1mm will prob add 20hp & will maintain the integrity of the walls as long as I'm not using it to race. You know the old saying bigger is better. What would be difference in performance between stock, 77.5 & 78 in your opinion?
     
  10. cct1

    cct1 Well-Known Member
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    #5 cct1, Jul 9, 2014
    Thread title just sounds so dirty to me, I'm afraid to read through all the posts....
     
  11. DJBishopNYC

    DJBishopNYC Member

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    #7 DJBishopNYC, Jul 11, 2014
    Yeah I'm just gonna stick with the 77.5 bore & get quick hp's from a 15% supercharger pulley, cold air intake, 49 state race manifold, free flow exhaust, 10mm plug wires & a bigger supercharger intercooler. This should be good for 50-60 hp's
     
  12. DJBishopNYC

    DJBishopNYC Member

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    #9 DJBishopNYC, Jul 12, 2014
    I'm changing the spark wires primarily to go to a blue theme. Blue wires, air intake, silicone coolant hose, silicone intercooler hose & break calipers. I'm not looking to make too much hp just enough to get it over 220 because like you said it can get expensive. I mean the crankshaft was $900 which more than twice as much & twice as small as a Ford 4.6 crank. smdh. Also I plan on selling her in about 2/3 years & I don't want to scare people away with mods some might fear is killing the life if the engine. Certain mods people like. Exhaust, brakes, radiators, pulleys, etc. & certain mods they don't. Headers, drops, fuel injectors, flywheels, etc. I want to maintain people's confidence of the quality. Anyway this is going to take a while to complete & I will post pics when I'm done. However this is where I'm at today. :([​IMG]
     
  13. rkw

    rkw Well-Known Member

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    #12 rkw, Jul 12, 2014
    Always check the Urban Dictionary before posting: Urban Dictionary: bore job