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Mazdaspeed 3 ECU Relocation Battery Box

Price: $179.99
Price in points: What are Points?180 points
Mazdaspeed 3 ECU Relocation Battery Box
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Introducing the 2007-2013 Mazdaspeed 3 ECU Relocation Battery Box. Protect your ECU, retain your OEM size battery, and provide clearance for up to a 3.5" intake! The battery and ECU relocation box feature a separate front ECU panel to improve ECU fitment as well as allow easier access to the battery. The box is manufactured via thermoforming from durable ABS plastic for a near OEM look and finish. #ZoomZoom!

2007-2013 Mazdaspeed 3 Battery Box Kit Video

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

The CorkSport Advantage

Mazdaspeed 3 battery box

3.5" Intake Clearance

By relocating the ECU to the battery box interior, the CorkSport ECU Relocation Battery Box protects the ECU from the elements and provides clearance for up to a 3.5" intake.

mazdaspeed 3 big intake battery box


CAD designed and manufactured from durable ABS, the CorkSport ECU Relocation Battery Box fits great and will stand up to the test of time.

OEM Fitment & Accessibility

The CorkSport ECU Relocation Battery Box features a three-panel design to improve the ECU fitment and battery access.

Performance Hardware

The CorkSport ECU Relocation Battery Box also includes an anodized aluminum battery tie-down bracket and easy-to-access thumb screws for the lid. No tools are necessary to access the battery.

mazdaspeed 3 aluminum battery tie downSpeed3 battery box

Additional Features

  • Compatible with:2007-2013 Mazdaspeed 3 with the OEM sized battery.
  • Designed & Developed in America: CorkSport Mazda Performance resides in Vancouver, Washington and is located in the beautiful 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 Mazdaspeed 3 ECU Relocation Box

It will take you an hour to install the CorkSport Mazdaspeed 3 ECU Relocation 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



installation instructions CorkSport Mazdaspeed 3 ECU Relocation Box

Fit perfectly in the car makes it look so much nicer with all the wires hidden. This is a must get with a bigger intake…
It's good for the USDM market batteries.

For EU batteries, keep an eye on their bottom. The battery has to be a literal cube; if it had an extension it won't fit, and the thumb screws will get in the way, especially the one in the right, and you won't be able to use the bracket.

You could account an OE type of retainer, that would save the trouble!
I'm a big Corksport fan and run a lot of their parts on my 2011 speed. This battery box fits great, ECU and wiring was not difficult to get into the box. I will agree with other reviews here that the box (plastic) is too thin and flimsy. My hope was that Corksport had fixed this after seeing the other reviews. The plastic needs to be at least twice as thick. Once that happens I would be closer to agreeing with the current price tag of $179.
Does not fit at all with jbr 3.5” tru path intake. Had to cut a large chunk out of the intake side of the box and temporarily zip tie my ecu to a diff location as this issue didn’t allow for using the front plate of the box where the ecu is supposed to mount.
Highly disappointed. Wasted money on something that said it would fit a 3.5” intake but actually does not and now need to spend more on a different option.
I've always appreciated the build quality and ease of installation with all my Corksport products, but I have to say I am extremely disappointed with this product. I like the functionality and look of this box but at a price point of $170 I expected the build quality to meet or exceed OEM build quality. This battery box feels like cheap plastic...way to flimsy to support the weight of a battery. The weight of the battery causes the box to lose its form making lining up the different sections difficult. I absolutely hate the approach taken with the battery tie down. I like the bracket but the hooks are terrible. An OEM design approach would have worked better here. The hooks took up just enough room inside the box to create too tight a fit for my battery making me have to cut a portion of the box out. Instructions could have come with better instructions about the best approach for fitting the ECU wires in the box and adjusting the lower right battery cable for easier fitment..What a PITA it was getting all the wires to fit. Of all the installs I've done I've spent the most on this one... I love Corksport products...just not this one:(
Maybe the thumb screw rods that supply downward pressure on the plate could have a reinforced section of the box to hold on to as they pull up on the thin plastic from below. I found the battery could still move around and was scared of damaging the bottom of the box if I screwed the thumb screws too much. I might add my own reinforcement later on the bottom so I can really tighten the thumb screws.
I love just about every Corksport item. While it does it's job well, I personally am less impressed by this one.

I would improve it by thickening up the bottom (possibly an aluminum base insert in the bottom?), so that box doesn't bow, when the tie-down bar is tightened and help it to support the ECU better. The inner side tie-down post is a very tight squeeze between the battery and the box wall.

Lastly, the description says it will accommodate a CS 3.5" intake. However, I have the 3" and it hit the ECU cover and cracked a portion off it. Overall, it could be a bit sturdier.

I am a Corksport fanboy. you know that. But I don't sugarcoat and I will always be honest. You don't have to post this review; just thought you'd like to see my personal review.
The box looks great. The install was kind of a pain but after I got the wires routed to was pretty easy.The box is flimsy and feels like its very fragile, the OEM battery box is thicker. Also if you don't have the battery that is in the instructions it won't fit. The Box could be made a little thicker especially considering the cost.
I had lost the cover to the oem battery box along with having a rats nest of wires from the ecu

this turned my engine bay from zero to hero in less than 30 minutes

very happy with my purchase and glad they did the development for it
box looks nice in car, easy install. The one thing the don't tell you is you need to have the oem battery size no aftermarket that are larger the box top will not fit if your battery isn't small enough. Another great product from corksport thanks again.
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would this fit the new 4in intake that yall came out with?

Asked by Julio Padron | 08/20/2023, 01:18 PM | 1 answer(s)

box dimensions?

Asked by reynaldo Sanchez | 11/13/2021, 08:00 AM | 1 answer(s)

What are the dimensions of the battery portion of the box/what is the biggest battery that can be put in here. Just wondering if I will be able to fit my current battery in there or if it will have to be replaced.

Asked by Blake | 04/19/2021, 12:27 AM | 1 answer(s)

Do the bolts line up for me to install on a Mazda 3 sedan 07??

Asked by Matthew  | 08/02/2020, 01:07 AM | 1 answer(s)

Will this work with a ms6? Would like to use your 3.5 inch intake

Asked by Harry Patton | 09/02/2018, 05:23 PM | 1 answer(s)

Will this fit my 2010 Mazda 3 Grand Touring (non speed)? Any alternatives?

Asked by Roger Palmdick | 01/20/2017, 04:48 AM | 1 answer(s)

2008.5 Speed 3, factory hood TMIC/Batt box ducting; I noticed the batt box port is lacking on the CS box, I can only assume this isn't a concern because you haven't included it in your design. At what point should I or might I be concerned about the ventilation of the batt box? Also, looking at my engine bay with the stock(!ugh!) intake box, it looks to me like the CS batt box might be a squeeze on its own (I know, CS SRI would solve that, it's on my 2do list hehehe, 1st things 1st).

Asked by Sean | 08/18/2016, 07:41 AM | 1 answer(s)

Will the optima red 35 fit this btry box also, Thank you

Asked by anthony.c | 09/25/2016, 11:22 AM | 1 answer(s)

Will a 4 inch intake fit with this box or is 3.5 inch the max?

Asked by Quinton | 09/24/2016, 01:24 PM | 1 answer(s)

If installed with CS front strut tower brace, can the battery be removed without having to remove the brace?

Asked by Elwood buchanan  | 11/16/2016, 01:37 AM | 0 answer(s)

Is this designed for a stock sized battery or 51R battery?

Asked by John  | 06/15/2016, 11:50 PM | 1 answer(s)

I have 3.5" JBR intake on GTX2867R... will it fit? What if i can't get it to fit, can i return it, and if so, how much $$ to return it?

Asked by Tony | 05/04/2016, 08:10 PM | 1 answer(s)

Is the battery going to crush ecu? The tie down only holds it down, not hold it back.

Asked by Angela Stires | 01/02/2016, 04:43 PM | 1 answer(s)

Will there be fitment issues with a cold air intake box?

Asked by Dominic Shinawatra | 12/29/2015, 07:57 AM | 1 answer(s)

Does this box make it possible to fit easily and use the Corksport 3.5" intake?

Asked by William Fletcher | 12/23/2015, 07:51 PM | 1 answer(s)

I can use this battery box in my mazda 3 s?

Asked by Atilano Aquino 01-42739 | 12/15/2015, 06:48 AM | 0 answer(s)

Does this require any extending of the ECU wiring? Are there any concerns with the ECU and battery getting too hot since they'll be enclosed?

Asked by Aziz | 10/28/2015, 03:51 PM | 3 answer(s)
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Will not work with BNR S4 V2 due to shift in a larger compressor outlet


2007-2013 Mazdaspeed 3
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  • 2012 Mazdaspeed 3
  • 2013 Mazdaspeed 3