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2007-2013 Mazdaspeed 3 51r Battery Box

Price: $199.99
Price in points:  What are Points? 200 points
Easy to use design allows the front and top to open to gain access to the battery and ECU
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CorkSport is proud to offer the first complete solution for your (up to) 4” intake, 51R battery, and ECU all in one clean enclosed package. Don’t settle for an engine bay full of loose wires, unprotected battery terminals and increased chance for corrosion. The CorkSport 51R ECU Relocation Box provides a clean setup relocating your ECU inside the box while providing ample clearance for your 51R battery and (up to) 4” intake. Manufactured from ABS plastic for an OEM fit, finish, and durability. #ZoomZoom!

Check out the installation instructions below. Share your performance review with the CorkSport community once installed!

The CorkSport Advantage


Performance Advantage

Designed to work with up to 4" intake systems, the 51r ECU Relocation Box provides approximately an extra 0.75" of clearance (compared to the full size CorkSport Battery box) without sacrificing fit and finish.

The ECU is relocated to the driver's side of the battery box with the wiring harness routed inside the box for a clean and purposeful look. The single lid design provides easy and ample access to the battery and ECU.

Mazdaspeed 3 51r battery kit

Fit & Finish

The 51r ECU Relocation Box is designed to use the OE mounting points for an easy installation with very little modification required to the wiring harness. The internal dimensions are designed around the industry standard 51r battery to fit all brands.

Mazdaspeed upgraded battery box

Materials & Manufacturing

CAD designed and manufactured from durable ABS plastic, the CorkSport 51r ECU Relocation box fits great and will stand up to the test of time. Battery restraint is completed with M6 studs and a 0.120" thick anodized aluminum plate.

Additional Features

  • Compatible with: 2007-2013 Mazdaspeed 3
  • Designed in America: Designed in Vancouver, Washington, in the Pacific Northwest.
  • CorkSport Service & Support: 2 year limited warranty, full color installation instructions, all necessary components, and knowledgeable telephone support at (360) 260-2675.

How To Install Your CorkSport 51r Battery Box

It will take you two hours to install the CorkSport 51r Battery Box with our easy-to-use instructions.

1 Hour Install Time

1 Hour Install Time

Difficulty: 2/5

2/5 Difficulty

2-Year Warranty

2-Year Warranty



Ok, well I wouldnt mind looking into it as maybe trying to mock one up to fit, I dont want just the plain old 51r tray. If I can get some that fits the 51r and has some aesthetically pleasing looks to it...Umm, like a Corksport Logo, Id much rather have that. Why do the Speed 3 owners get all this stuff anyways but the sixes get pushed the Speed 3 lower front lip, the battery box, the steering guys should make a carbon fiber trunk lip for the speed 6 similar to like an M1 I think. If i could get some pictures of the Speed 3 battery box from all sides, the bottom and inside and dimensions, so I can check to see if its even worth trying. THanks

Asked by Tim | 10/24/2017, 07:50 AM | 1 answer(s)

I understand its not listed for a speed6...but what exactly is so different in the battery/ecu area that this couldnt fit, it looks like a beautiful product. I am looking to put in your guys 3 inch intake to add to my already CS turbo and pump internals n map sensor n EBCS, but I'm reading alot of people say you need an ecu relocation or a 51r battery to make anything fit as big as the 3inchers or larger. I've also read people fit them with no problem so I dont know. I know this seems like an intake question, but I was really wondering if this would fit in my speed not an r tard, I realize you don't list as fitting that...would it take extensive work TOO fit?

Asked by Tim | 09/26/2017, 10:32 AM | 1 answer(s)

Is the factory Panasonic battery in the 2013 ms3 considered a 51r?

Asked by Kirk | 09/12/2017, 01:23 PM | 1 answer(s)

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Corksport understands that you may be ready to outfit your entire car with CorkSport Mazda Performance products, but want to use an alternative method of payment. Not to worry, we have a solution for you.

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Will not work with BNR S4 V2 due to shift in a larger compressor outlet