Mazdaspeed "Dog Box" 5-speed Gearset Kit - Deposit

This is the Deposit Only: Total price is $6695 and will be paid over 4 payments.  Total estimated timeline for the project is approximately 12 months. Project is starting March 2025.

Please email barett@contrive.design for Purchase Agreement. 

We have finalized gear ratios and I'm excited to say I think this is a great setup for the overall community.  I went through upwards of 17 different ratio stacks to get to this point.  The process is long and tedious but necessary.  I've learned alot in the process about gears and how ratios are finally determined.  Its more than just pick a ratio, it has a lot to do with the actual design of the tooth itself and how it interacts with its counter tooth.  There are "ranges" of tooth size to balance strength, durability and drivability that all have to be considered.  These variables all lead to set ratio options to choose from.  Its been a fun exercise. 

Now the ratios below are about 95% certain, once we get into more manufacturing review there might be a slight change but should not be anything major...like changing ration 0.05 or so...

Ok so the details: 

Gear Ratio Stack: 

1st - 2.917

2nd - 1.938

3rd - 1.350

4th - 1.042

5th - 1.042 (5th has to be the same ratio but because the final drive is different for 5th/6th there is a ratio change at the tire) 

What is part of the Dog Box Gearset Kit: 

- Input shaft with larger GM26 spline

- 1-4 gears helical cut w/dog engagement

- 5th gear helical cut w/OEM synchro engagement

- Dog engagement slide rings for 1-2 & 3-4

- Billet Shift Forks for 1-2 & 3-4

- Matching Reverse Gear

- Triple Shaft Cuff Collar located at 6th gear location (or if you want to retain 6th you do not use the collar) 

- Gear Material 9310

So, the OEM Final Drive is retained and used in this kit and for good reasons: 

• It reduces cost and allows us to add the very needed cuff collar and use the best material out there for increased strength and durability. 
• Retaining the OEM final drives gives you the option of final drive ratio and overall top speed per gear.  If you are drag racing then perhaps you want the longer GEN1 final drive.  If you are street and circuit track then perhaps the shorter GEN2 final drive is better.  The point is you get to decide and the gear ratio stack was reviewed and considered to be a best case scenario for both final drive options.

Now you may have concern about the final drive strength being "OEM".  This has been reviewed and discussed in detail with my manufacturer.  They are confident the ring gear is well up to the task of holding power.  If you have concern and/or are looking towards the 4 digit power numbers then there is an option to help increase the strength of the OEM final drive with a shot peen and polish process.  This has proven to be a ~10% increase in strength and helps remove internal stress of the parts.  All good things.  

Pricing Structure:

• Total Price: $6695+ shipping
• A Purchase Agreement will be required and there is no refund once deposit and following payments are made. If you need to bail out, then you need to find someone else to take your spot, and you will only receive a partial refund. 
  
• Payment Schedule: 
  • Deposit Due March 28th: $1500
  • Payment 2 Due June 4th: $1500
  • Payment 3 Due Sept 17th: $2000
  • Final Payment Due TBD when ready to ship. Estimated Feb-Mar 2026: $1695

What else is needed to get this into your car?

- Some bearings used in the transmission will need to be replaced and some shims will need to be replaced.  This is a few hundred dollars.

- New clutch disc (only the clutch disc, an entire new clutch is not required) to accommodate the larger GM 26 spline input shaft.

- Assembly is an in-depth process but is NOT impossible to do if you have a press, basic tools and patience.

- I may consider offering assembly services for an additional price+shipping.

FAQ:

- Does this fit my car?  This gearset is designed to work on the 2006-2007 Mazdaspeed 6 and both generations Mazdaspeed 3 2007-2013. 

- Can a dog box transmission be driven on the street?    Yes, but it requires more intent while driving.  If the car you are thinking of adding a dog box to is your daily driver then I would recommend not doing this, but if it’s an “extra fun car” then I think it could be a great addition. 

- Check out this video from PPG about driving a dog box on the street.

https://www.youtube.com/watch?v=n_1jO64tuQA   

- How much power can this handle and do I need to make at least 500+hp? The design and material choice is be developed to support 1000+whp and there is no minimum horsepower required to utilize a dog box gearset.

- Is this a whole new transmission? NO, this replaces the internal gears, shift forks and input shaft only.  The OEM ring gear, output shafts and case are reused.  Some of the bearings will need replaced and some can be reused.

- What is the warranty? This is a motorsport part, thus if it is opened, installed, used…etc then you own it.  If there is a manufacturing defect or issue, then the parts will need to be inspected and assessed to determine how to action.