• Castro Motorsports LS7 swapped E46 M3 - Badass? Blasphemy?

      It is almost getting boring seeing LSX motors in just about everything. Yes, the engines are awesome. Simple, cheap (relatively compared to BMW M engines), light, easy to work on, powerful, tons of modifications, etc. The S54 inline-6 is the heart and soul of the E46 M3 and putting in a Chevy powerplant no matter how good just seems wrong somehow. That said, it is great to see a large V8 stuffed under the hood of the E46 and no doubt the car is a monster.

      Would you would want one? Would you still consider it a BMW? Did it lose its heart and its soul in this swap? Debate, discuss, drool, or condemn.





      Build:











      Since this is going to be a race car, we were able to make life easier on ourselves in this process, by deleting/permanently removing what wasn't absolutely necessary. After all, race cars aren't meant to be comfortable, but they definitely need to be light. We also needed to make firewall and trans tunnel modifications with our good friend - the Hammer, as we planned to move the motor further back then for better weight distribution.





      After doing plenty of research on various LS swaps, and seeing that we wanted to put this motor into multiple chassis in the future, we invested in a nice replica foam block engine. For the price you really can't beat this option IMO. The engine weighs less than 20 lbs, and has threaded nut-serts to be able to bolt up literally everything that a real LS would have! We also went ahead and started ordering materials for the engine mounts, and the headers.

      Anyway Chris and Jose got to work and came up with these engine mount arms. These were made to work with the AKG solid aluminum engine mounts that were on their way.











      The rear suspension was addressed next - AKG solid aluminum rear subframe bushings, trailing arm bushings and diff bushings were installed, along with their weld-in reinforcement kit.









      Here are some pictures of how the motor sits with the mounts in place. The stock rubber M3 mounts were used as place holders for the solid AKG mounts that were on back-order.



      The biggest issue, as with the E36 kit that are offered, was going to be the driver's side header. Since we're using 1 7/8" primaries, this was going to be tricky, especially since we moved the firewall in about 3 inches to sit the





      Since we're working within a deadline, we had to get moving on the headers. Oh hey, I wonder what's in that box?







      Since the passenger side was going to be easier, Chris and Jose tackled that side first





















      More work on the passenger side header:





      Basically done
















      The passenger side floor was cut for the DTM style, side exit exhaust. Way more work then I thought! :shock:







      A mock up of the muffler with dual 4" tips



      The new floor plate made, and was welded in





      Transmission brace completed



      Custom dual 3" X-pipe!











      DTM style exhaust - 80% complete







      O2 bungs added to the X-pipe





      Exhaust complete, with the tips slash cut to be parallel with the side skirt. Side skirt was cut nicely for a clean look







      Harness redone, wrapped, and ready to be installed



      Oh, and the REAL motor was finally installed




      Mmm, CNC ported heads by West Coast Cylinder Heads!



      Close up of the Dailey Engineering Stage 3 dry sump pump






      Close up of the custom ATI Super Damper



      The KW Club Sport coil-overs were also installed!













      ***The 2x4 pictured holding up the hood, was unfortunately our only option after Kalon lost the aluminum rod we had put in the truck when he left the shop***



      Decals installed





      This article was originally published in forum thread: Castro Motorsports LS7 swapped E46 M3 - Badass? Blasphemy? started by Sticky View original post
      Comments 24 Comments
      1. bobS's Avatar
        bobS -
        Very cool. The s54 is a amazing motor but this is a great project. I wouldn't mind having a LS swapped m3. I thought about doing it with a e36 m3 a while back.
      1. SLV335I's Avatar
        SLV335I -
        I love it and would take it in a second.
      1. Group.america's Avatar
        Group.america -
        It's a racing car..... yada yada yada............ and with the LSx, Kw coilovers, etc etc, the only thing BMW about this car is the shell

        Great engine though !
      1. E90Company's Avatar
        E90Company -
        Wow that's awesome.
      1. onisyndicate's Avatar
        onisyndicate -
        I don't like the side exhaust. But I see the valid points for a race car have a LS in it. You can literally go down to the parts store and most likely get the parts. The 240 SX drift crowd will do a LS swap just for that reason.

        Now would I do it to a M bmw no. but a 325is, 318i or a 540i Wagon on HELL YES!
      1. 135pats's Avatar
        135pats -
        No longer a BMW but I guess it's cool.
      1. fastgti69's Avatar
        fastgti69 -
        I think it's pretty cool. One of the best balanced chassis, and one of the best NA motors. Put them together and you get this masterpiece.
      1. BigM62's Avatar
        BigM62 -
        Click here to enlarge Originally Posted by fastgti69 Click here to enlarge
        I think it's pretty cool. One of the best balanced chassis, and one of the best NA motors. Put them together and you get this masterpiece.
        Curious, is "one of the best balanced chassis" better than a 'Vette chassis? Otherwise, all that work for what? Awesome fab skills and build though.
      1. fastgti69's Avatar
        fastgti69 -
        Click here to enlarge Originally Posted by BigM62 Click here to enlarge
        Curious, is "one of the best balanced chassis" better than a 'Vette chassis? Otherwise, all that work for what? Awesome fab skills and build though.
        Vette is too long to be as nimble as the e46, I've driven both cars and the e46 just feels 100X better than the Vette.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by fastgti69 Click here to enlarge
        Vette is too long to be as nimble as the e46, I've driven both cars and the e46 just feels 100X better than the Vette.
        The C7 is even better balanced and supposedly far more playful and nimble. I'll know for myself soon hopefully.
      1. onisyndicate's Avatar
        onisyndicate -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        The C7 is even better balanced and supposedly far more playful and nimble. I'll know for myself soon hopefully.
        My friend Jacklyn's Husband just took keys of a white C7 on valentines day. He hasn't really taken it out yet. It looks pretty sweet though!
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by onisyndicate Click here to enlarge
        My friend Jacklyn's Husband just took keys of a white C7 on valentines day. He hasn't really taken it out yet. It looks pretty sweet though!
        What does he do with it? Stare at it in the garage?
      1. SLV335I's Avatar
        SLV335I -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        What does he do with it? Stare at it in the garage?
        Maybe there's snow outside.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by SLV335I Click here to enlarge
        Maybe there's snow outside.
        I don't know what that is.
      1. BigM62's Avatar
        BigM62 -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        I don't know what that is.
        Yes you do. It is what you drive to.
      1. onisyndicate's Avatar
        onisyndicate -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        What does he do with it? Stare at it in the garage?
        Well it just finally cleared up with the snow in KS. So yeah pretty much. He's driven it a couple of times. When he goes to the strip (3 hours south of us) I'll ask him to send me the video and a photo of the time slips.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by BigM62 Click here to enlarge
        Yes you do. It is what you drive to.
        In my all wheel drive car Click here to enlarge
      1. G0TB00ST?'s Avatar
        G0TB00ST? -
        This is so wrong... but its soooooo right


        this thing will be a monster thats for sure
      1. Aryan_M3's Avatar
        Aryan_M3 -
        damm!!!1
      1. StinkyM's Avatar
        StinkyM -
        This is stupid. I wish I could burn every LS swapped BMW. I wish I could drive every 911 with a LS power plant off a cliff though. The former is like shooting someone from far away, the latter is like stabbing someone and staring them in the eyes.