Results 1 to 17 of 17

Thread: Remove/De-cat your OEM S85 V10 headers - DIY (do it yourself) removing the major restriction of the catalytic conveters

              
  1. #1
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    98,929
    Rep Points
    23,618.6
    Mentioned
    1471 Post(s)
    Rep Power
    237


    Reputation: Yes | No

    Remove/De-cat your OEM S85 V10 headers - DIY (do it yourself) removing the major restriction of the catalytic conveters

    Found this DIY and thought it was pretty good for those who want a cheap way to get gains from their OEM S85 headers considering the cost of the aftermarket pieces:

    Estimated Time: 6~ hours for just gutting the cat.

    Tools:

    - Dewalt 8A Corded Drill with 3/8" chuck (Link)
    - Kobalt 11" Straight Nose Pliers (Link)
    - LENOX 1-1/8" Hole Saw with Pilot Bit (Link)
    - 3/4" Cold Chisel (Link)
    - 3/8" Irwin 5.5" extensions (x2) Link
    - Drill Lubricant (5w30 motor oil will do as well) to maintain heat temps low on drilling
    - Long 12-14" Flathead screwdriver
    - Shop Vac
    - Gloves
    - Protective Eyeware
    - Respirator/Dust Mask
    - Jack stand to support the manifold at an angle

    Preferable work area: Since it was only me, I needed a way to prevent the exhaust manifold from moving back when drilling/chiseling, so I rested it against my garage wall and supported the outlet side with the jack to help me hold it at angle.

    DIY:

    1. Begin by removing exhaust manifolds. <TO DO: insert link to reference exhaust removal here>

    2. Prep yourself with protection (mask,gloves,eyeware)

    3. Prep your area(towels, jack stand, supports, etc.)

    4. Prep your tools.
    4a. Ensure your pilot drill bit is tightly secured onto the hole saw otherwise it may be a pain to remove if it gets stuck in the catalytic
    4b. Connect your two extensions and hole saw to your corded drill

    5. Support your exhaust header like so:

    Click here to enlarge


    NOTE: See all the shiz that comes out, wear eye and face protection from dust and shiz!

    6. In this picture you will see the honeycomb material that identifies the catalytic converter.

    Click here to enlarge


    7. What I did was started drilling three holes(lube the bit and hole saw each drill) in a triangular fashion starting from the outside(if any of you have a better plan of attack, lets hear it)

    Click here to enlarge


    8. Now that you have drilled your first three holes, we want to try and break that material up into pieces to allow us to drill further on those holes. You can use the needle nose pliers and a large flat head to help seperate them.
    <TO DO: Pending Pic Here of initial three drilled holes>

    9. You should see your pilot hole in each cut. Using this as a reference, take your cold chisel and punch two sections as a cross pattern(vertical and horizontal punch) down to the depthness of the hole saw. That should help with breaking up the pieces of the catalytic. You may need to punch two additional sections on the hole from 10' to 4' o clock and 2' to 8'.

    10. Repeat steps 6-9 on the other areas of the catalytic converter.

    11. Now that you have your initial drilling out of the way, you can continue using your hole saw with the pilot bit as it will probably take three cuts to fully get through the cat. On the last cut, you should be able to remove the pilot bit and drill straight through.

    NOTE: ENSURE YOUR CUTS ARE SMALL ENOUGH TO HELP TWIST/BREAK THE HONEYCOMB MATERIAL OUT OF THE PIPING.

    12. Essentially, you will be left with this:

    Click here to enlarge

    13. You may need to further scrape off the honeycomb material from the piping, I had to use the screwdriver,cold chisel and even the crowbar at an angle. See pics:

    Click here to enlarge


    Click here to enlarge
    $100 fantasy football league, register here (ONE SPOT OPEN): http://www.germanboost.com/showthrea...ague-2014-2015

  2. #2
    Join Date
    Apr 2010
    Posts
    326
    Rep Points
    512.0
    Mentioned
    2 Post(s)
    Rep Power
    6


    Reputation: Yes | No
    interesting

  3. #3
    Join Date
    Feb 2010
    Location
    NJ
    Posts
    13,472
    Rep Points
    48.0
    Mentioned
    318 Post(s)
    Rep Power
    0


    Reputation: Yes | No
    Ive contemplated doing this to my 2ndary cats.. hhmmm

  4. #4
    Join Date
    Aug 2010
    Location
    Valley Stream NY
    Posts
    3,187
    Rep Points
    2,603.5
    Mentioned
    81 Post(s)
    Rep Power
    27


    Reputation: Yes | No
    I wouldnt usually recommend doing it. Creates extra turbulence in the exhaust stream, due to the exhaust expanding and slowing down to fill the void, then cram back into the pipe and speed up again.

  5. #5
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    98,929
    Rep Points
    23,618.6
    Mentioned
    1471 Post(s)
    Rep Power
    237


    Reputation: Yes | No

    Click here to enlarge Originally Posted by Itsbrokeagain Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    I wouldnt usually recommend doing it. Creates extra turbulence in the exhaust stream, due to the exhaust expanding and slowing down to fill the void, then cram back into the pipe and speed up again.
    Has to be better than having cats.
    $100 fantasy football league, register here (ONE SPOT OPEN): http://www.germanboost.com/showthrea...ague-2014-2015

  6. #6
    Join Date
    Aug 2010
    Location
    Valley Stream NY
    Posts
    3,187
    Rep Points
    2,603.5
    Mentioned
    81 Post(s)
    Rep Power
    27


    Reputation: Yes | No
    You would think, but I had a former customer with catless downpipes installed on his X5M and he lost hp on the dyno...so BMW might have a reason to their madness..

  7. #7
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    98,929
    Rep Points
    23,618.6
    Mentioned
    1471 Post(s)
    Rep Power
    237


    Reputation: Yes | No

    Click here to enlarge Originally Posted by Itsbrokeagain Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    You would think, but I had a former customer with catless downpipes installed on his X5M and he lost hp on the dyno...so BMW might have a reason to their madness..
    That's a turbo motor with a different design though.

    On the NA M motors, from what I have seen, cats right off the header are a significant restriction. Just look at the E46 M3.
    $100 fantasy football league, register here (ONE SPOT OPEN): http://www.germanboost.com/showthrea...ague-2014-2015

  8. #8
    Join Date
    Aug 2010
    Location
    Valley Stream NY
    Posts
    3,187
    Rep Points
    2,603.5
    Mentioned
    81 Post(s)
    Rep Power
    27


    Reputation: Yes | No
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    That's a turbo motor with a different design though.

    On the NA M motors, from what I have seen, cats right off the header are a significant restriction. Just look at the E46 M3.

    You might have a point. But we are looking at havingvto remove the headers to do this....for the money it costs to do so, Id go buy the Evolve set and install those...more hp gained for time spent labor wise. If you could do this on the car, then yeah its possibly worth it.

  9. #9
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    98,929
    Rep Points
    23,618.6
    Mentioned
    1471 Post(s)
    Rep Power
    237


    Reputation: Yes | No

    Click here to enlarge Originally Posted by Itsbrokeagain Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    You might have a point. But we are looking at havingvto remove the headers to do this....for the money it costs to do so, Id go buy the Evolve set and install those...more hp gained for time spent labor wise. If you could do this on the car, then yeah its possibly worth it.
    Well most headers on the S85 V10 are priced absurdly high so it makes sense for many people.
    $100 fantasy football league, register here (ONE SPOT OPEN): http://www.germanboost.com/showthrea...ague-2014-2015

  10. #10
    Join Date
    Dec 2012
    Posts
    23
    Rep Points
    120.3
    Mentioned
    0 Post(s)
    Rep Power
    2


    Reputation: Yes | No
    Anyone attempted this on the forum?

  11. #11
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    98,929
    Rep Points
    23,618.6
    Mentioned
    1471 Post(s)
    Rep Power
    237


    Reputation: Yes | No

    Click here to enlarge Originally Posted by heavytiresmoke Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    Anyone attempted this on the forum?
    Nobody here I know of.

  12. #12
    Join Date
    Nov 2012
    Location
    Chicago
    Posts
    6
    Rep Points
    11.5
    Mentioned
    0 Post(s)
    Rep Power
    0


    1 out of 1 members liked this post. Reputation: Yes | No
    I did it to mine. Headers still on car when I did it, too.

    No before/after dyno numbers tho, due to the car having been out of commission for the 4 prior Months.

  13. #13
    Join Date
    Apr 2010
    Location
    USA
    Posts
    590
    Rep Points
    688.1
    Mentioned
    15 Post(s)
    Rep Power
    7


    Reputation: Yes | No
    Click here to enlarge Originally Posted by Cartek Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    I did it to mine. Headers still on car when I did it, too.

    No before/after dyno numbers tho, due to the car having been out of commission for the 4 prior Months.
    You were able to drill the cars out, with the headers still on the car?
    ///M5 LCI
    "It's like the F10 is the 911 Turbo to the E60's GT3" -Pistonheads (M5 feature)

  14. #14
    Join Date
    Nov 2012
    Location
    Chicago
    Posts
    6
    Rep Points
    11.5
    Mentioned
    0 Post(s)
    Rep Power
    0


    1 out of 1 members liked this post. Reputation: Yes | No
    Yessir. Car was on a lift. Took me about 3.5 hours.

  15. #15
    Join Date
    Nov 2012
    Location
    Chicago
    Posts
    6
    Rep Points
    11.5
    Mentioned
    0 Post(s)
    Rep Power
    0


    1 out of 1 members liked this post. Reputation: Yes | No
    I have a thread about it. I'll find it and post the Info here for you.

    :-)

  16. #16
    Join Date
    Apr 2010
    Location
    USA
    Posts
    590
    Rep Points
    688.1
    Mentioned
    15 Post(s)
    Rep Power
    7


    Reputation: Yes | No
    Click here to enlarge Originally Posted by Cartek Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    I have a thread about it. I'll find it and post the Info here for you.

    :-)
    Awesome! This sounds like a good mod to do with the stock headers, leaving them installed makes the job 100 times easier.
    ///M5 LCI
    "It's like the F10 is the 911 Turbo to the E60's GT3" -Pistonheads (M5 feature)

  17. #17
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    98,929
    Rep Points
    23,618.6
    Mentioned
    1471 Post(s)
    Rep Power
    237


    Reputation: Yes | No

    Click here to enlarge Originally Posted by Cartek Click here to enlarge
    This quote is hidden because you are ignoring this member. Show Quote
    Yessir. Car was on a lift. Took me about 3.5 hours.
    That's not bad at all...

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •