This project began after slaying the Tail of The Dragon’s 318 curves last October. We determined that the new Mazda 3 would benefit from additional bracing, and we are currently testing the first round of prototypes. In this blog, we will go into the development process of the Rear Hatch Brace and the steps we took to get to our current sample, which will be the design you can purchase for your hatch in the coming months.
This project began by searching for suitable mounting locations to tie the brackets and cross bars into the chassis effectively. After removing a good amount of the hatch trim panels, we found that the existing mounting locations for the seat back latch were a perfect spot to use as the location for the main cross bar brackets since they are tied into a main chassis structure. They also feature two M10 bolt locations perfect for providing a secure bracket mounting point.
After we nailed down the main cross bar’s mounting locations, we looked for another spot to tie in additional bars required to triangulate the brace. The bracket that links the rear seats back together was an obvious choice since it also offered two M10 mounting locations that were easily accessible. The CAD model depicts the brackets below, which are highlighted in blue.
Once we identified all the mounting locations, the next step was to move on to designing the brackets and cross bars. This process was considerably easier since we created the parts using the Mazda 3 hatch chassis in CAD, as seen above. The first components to be designed were the brackets. The brackets needed to match the angle of the rear seats without sticking out too far into the storage space to retain the practicality and usability of the hatch.
Retaining practicality is also the main reason why we wanted the brackets and cross bars to be separate. If you ever need to remove them for additional space, it can be done quickly without removing any trim pieces. We also wanted to provide two configurations or “Stages” of the RHB to give you more options. Once all these constraints were taken into consideration, it resulted in our bracket design, which is currently being tested on one of our shop cars. Below you can also see a comparison between the CAD model’s Stage 1 and 2 configurations.
Stage 1 – Single Bar System
Stage 2 – Triple Bar System
For the design of the cross bars, we initially started with an alternative design and material. The first iteration of the cross bars featured a round tube that would be welded to bent sheet metal end brackets to provide a mounting surface to interface with the brackets attached to the chassis. While this design would have been functional, it looked less OEM than we wanted. Additionally, it would have added considerable difficulty to the RHB’s manufacturing and overall cost.
We decided to search for a better solution that would function as expected while also improving in the areas the previous design lacked. Over the course of the design process, we moved to a rectangular tube as the stock material. The R&D process resulted in the rectangular cross bars we are testing on the car now. A comparison between the two designs is highlighted in the images below.
The last detail of the Mazda 3 Rear Hatch Brace is all the hardware tying the brackets and cross bars together, along with the coating used on the parts. For the hardware, we wanted to provide bolts that matched the clean look of the brace and complemented the look we were going for. That led to us selecting countersunk bolts and finishing washers which are stainless steel for excellent corrosion resistance and help add the extra flare we were shooting for. The cross bars and brackets are textured black powder coat, further complimenting the factory interior while providing a rugged finish. As you can see below, the results are beefy!
Thank you for reviewing the details of the design process of the CorkSportRear Hatch Brace. If you are interested in picking one up for your 4th Gen Mazda 3 Hatch, stay on the lookout – it will be hitting the website in the coming months.
When lowering your car with coilovers or lowering springs, you will need an alignment to reset the suspension geometry for optimal performance and tire wear. One of the key aspects of this alignment is the camber.
The suspension alignment of your Mazda can completely change the way the car handles, brakes, and accelerates. Camber is one of the critical variables in an alignment that needs to be set up for your Mazda and for your driving needs. Let’s talk about camber and why you might need camber plates.
Camber (aka camber angle) is the measured angle of the wheel/tire centerline vs true vertical. Any measurement in angles is typically expressed in degrees in the automotive world and can be stated as negative, neutral/zero or positive degrees of camber.
In the image below we have a diagram showing a mock setup with a MacPherson strut suspension style. MacPherson struts setups are common in passenger cars and are used in the Mazda 3, Mazda 6, CX5, CX9, & CX50.
Camber Diagram Breakdown:
The thin red arching part represents the chassis and fender of the vehicle.
The grey color components represent the lower control arm and the strut assembly (MacPherson Strut).
The black thing that looks like a tire…is the tire and wheel.
The green line represents “True Vertical” so we can see the camber .
The blue line represents the “Wheel/Tire Centerline” and will change angles depending on camber.
Let’s assume the vehicle is sitting on the ground and we are facing the front of the vehicle driver’s side. When the vehicle is sitting on the tires this is considered our “static ride height”. This is important to note because this is how the vehicle’s static alignment is measured. Let’s break down the adjustments of camber.
Negative Camber:
Negative camber is when the top of the tire leans inward towards the center of the vehicle. A typical amount of negative camber for a street-use vehicle is negative 0.5 – 1.0 degrees in the front and slightly more negative 0.8 – 1.5 degrees in the rear. This provides a good balance of performance cornering grip, braking, accelerating and tire wear. The slightly more negative rear camber aids making the car more oversteer prone which is safer for the average driver.
The Pros of Negative Camber:
Negative camber is critical to the suspension alignment as it directly affects the total mechanical grip of the tire. Negative camber helps keep the tire contact patch in full contact with the road surface during corning. When the vehicle is sitting or driving straight the tire is leaned inwards slightly with negative camber. When you turn the vehicle typically leans outward slightly (body roll) and thus affects the tire contact patch. The static negative camber counteracts that body roll, keeping the tire contact patch flat to the ground when you have a body roll from turning.
The Cons of Negative Camber:
Negative camber reduces the overall tire contact patch size in straight-line driving. This affects braking and acceleration due to the reduced contact patch size. Too much negative camber, typically more than negative 3 degrees, will drastically affect this to the point that it may make the vehicle unsafe to drive on public roads. So, negative camber is a balancing act of too little vs too much and should be professionally adjusted to benefit the overall suspension setup and use of the vehicle.
Positive Camber:
Positive camber is not typically used on a street and/or road course racing car. With positive camber, you would have the cons of camber in straight line performance braking and acceleration and even worse performance in turn as the positive camber would exaggerate the body lean. If you have positive camber, it is highly recommended to inspect your suspension for issues and/or get the vehicle aligned and adjusted.
However, there are exceptions to this. In very specific racing environments such as oval circuit races. Negative camber on the outside tires and positive camber on the inside tires can be beneficial because the vehicle is only ever turning in one direction. Therefore all four tires (not just the outside tires) are counteracting the body lean of the vehicle while turning.
Static vs Dynamic Camber:
Camber can be defined in two forms; static and dynamic.
Static Camber is when the vehicle is sitting on the tires (aka at rest). This is how alignment shops measure the vehicle’s alignment including camber.
Dynamic Camber is the resulting camber as the wheel/tire moves up and down in the suspension travel.
When an individual speaks to their camber setup, they are most likely talking about their static camber. Dynamic camber is not easy to measure without knowing the geometry of the suspension itself. Dynamic camber changes as the suspension travels up and down. Typically as the wheel/tire travels up from ride height (aka bump travel), there is more negative camber called camber gain. The opposite follows when the wheel/tires travel down from ride height (aka droop travel), there is less negative camber called camber loss, and can even become positive camber with some suspension styles.
Camber Gain in Bump, Static Ride height, & Droop
In a MacPherson Strut-style front suspension (Mazda’s go-to setup), the camber gain is fairly minimal at typically less than 1 degree of negative camber gained in the first bit of suspension travel. As the suspension excessively compresses in bump, the camber gain is typically reduced or lost. This is called the camber gain curve and is described as a curve because it is dynamically changing as the suspension travels up and down.
Reviewing the above diagram there are three images showing the change in camber due to camber gain/loss. Watching the relation of the blue and green lines, you can see the chamber change depending on wheel/tire travel.
Middle Image: Shows static ride height at neutral/zero camber. This can be seen with the blue and green lines, they are parallel.
Left Image: Shows bump travel camber gain. The blue and green lines are intersecting at the top and have a larger gap at the bottom.
Right Image: Shows droop travel camber loss. The blue and green lines have a gap at the top and are intersecting at the bottom.
As you can see, camber is a very dynamic aspect of the suspension geometry that affects many aspects of the vehicle. Cornering, braking and accelerating are all directly affected by dynamic camber, but this all start with your static camber setup.
Let’s be real, static camber is how you fit those new wheels and tires you are so excited about; so let’s talk more about camber and its effect on fitting those wheels and tires. Static camber, as discussed above, sets your baseline camber for the dynamic camber to “build off of” through suspension travel.
Static Camber + Camber Gain = Wheel/Tire Clearance to Fender
Here you can see a diagram of wheel/tire clearance to the front fender when the suspension is in bump travel.
The more negative the static camber is, the more fender-to-tire clearance you have in bump travel.
Your chosen wheel and tire setup will also have an effect on this clearance due to the many different widths and offsets you can choose. Generally, the smaller the offset, the more the wheel will “poke” outward from the side of the vehicle. Wheel width and offset are the key aspects to fitting a wheel on a given setup. Typically your Mazda 3 is going to need a fairly conservative wheel and tire setup to fit without excessive negative camber.
Instead of trying to explain all the details about wheel and tire fitment setup, I’ll point you to a fantastic website that allows you to input your existing wheel and tire setup and compare to your new setup. The website outputs a great visual diagram of the current and new setup with measurements you can reference. See: www.willtheyfit.com
Here is an example of our wheel and tire setup vs the OEM wheel and tire setup. This is currently on our 2021 Mazda 3 Turbo Hatch. It looks fantastic and performs great with our Turbo Lowering Springs and our Coilovers.
Lastly, camber is not the only suspension setting affected by lowering your car on springs or coilovers. Toe is the next critical suspension setting that needs to be corrected after camber is set in place. Toe also drastically affects how the vehicle drives and will quickly destroy tires if not setup correctly for the intended driving.
Most MacPherson struts do not have any camber adjustability from the OEM, so what do you do? Depending on the amount of drop from your lowering springs and your driving needs, you may need to purchase aftermarket camber plates to get your suspension dialed in or to prevent your meaty wheel and tire setup from rubbing!
So, the moral of the story. When lowering your car, make sure to get a proper alignment for the betterment of your vehicle’s performance and the longevity of your tires! Don’t go too crazy with camber; remember it’s a balancing of performance, durability, and fitment.
Thanks for tuning in, we hope this was a helpful blog about camber setup for your Mazda!
Racing is brutal! When pushing a vehicle to the razor’s edge, you tend to find the platform’s limitations rather quickly – then set out to overcome them! This is precisely where the CorkSport 3rd & 4th Upgrade Gears come in.
In the years of racing our Touring Car class Mazda 3, we found many pitfalls that have been easy to overcome. However, we found the gears’ limit with the 317whp/355wtq of the CorkSport Turbo Kit pumping through the manual transmission. Pair that with a limited-slip differential and wide sticky racing tires…well, it’s shocking the drivetrain has held up as well as it has.
Destroying a transmission during a race weekend was not a viable path to success, so we developed our own race-quality CorkSport High Strength Gears to solve the problem. As you might imagine, this posed some significant challenges. For example, to retain the 6-speed setup, we had to stick with the same gear widths – which are very narrow.
To gain the strength and durability needed, we opted to use a higher strength material; SAE9310 steel, and to further increase the durability, the surfaces are shot peened. The shot peening process helps durability by reducing the chances for stress cracks to develop, increasing fatigue life and bending strength.
Since then, we have been running these gears in our TC Racing Car for a complete season to validate that there are, in fact, better than OEM. Racing is the ultimate test for performance parts, and we are happy to report the transmission has caught every shift!
So why might you need these upgrade gears? Do you have a turbo or supercharger kit on your manual Mazda 3 or Mazda 6? Do you like driving your car hard and even doing some structured racing events? If yes, these may be in your future, so you can push your Mazda to the limits without worrying.
Part 2 of the Mazdaspeed3 AWD Swap blogs, we are going to get a baseline weight, show you some of the parts going into the car and finally tease you with cantilever suspension. Have a seat and grab a drink!
Before I started the AWD swap on my half-mile drag-racing Mazdaspeed 3 I wanted to get a baseline weight and weight distribution. Without a driver, my 2009 Mazdaspeed 3 weighed in at 3000 pounds on the money with just under 2000 pounds on the front wheels and just over 1000 pounds on the rear axle.
Corner weights are actually pretty damn good, but this is without my weight in the car. Adding me to the equation would throw that off a good amount. Either we have a baseline that we can compare to later once the car is back to 100% with AWD.
Now this may not be a perfect back-to-back test but it’s something…which is better than nothing. At the time of weigh-in, the Speed3 has an 8-point cage, composite driver seat and basic reclining aftermarket passenger seat, harnesses for both, stripped interior for everything behind the driver.
The components that are changing for the AWD swap:
Firewall Structure to separate the Radium Fuel Cell from the driver compartment
Alright so let’s talk about some of these components that are changing. Firstly is the fuel system. Currently, I am running a dual fuel system featuring the CorkSport Fender Fuel Cell with E98 in it feeding the port injection system and the stock fuel tank with an E48 blend in it.
While this kit has taken me to 650+whp with the CorkSport CST6 Turbo and nearly 900 WHP with a larger turbo and fuel pump…it’s time to really focus the build to a more dedicated racing fuel system.
Enter the Radium “FCST” System; this is a full standalone fuel system that is FIA-certified and incorporates the 10-gallon fuel cell, an internal surge tank, and a fuel level sensor.
For my setup, I will be using a single 525LPH “in-tank” pump inside the fuel cell feeding the surge tank which then feeds to external pumps. This 525LPH fuel pump is mounted to the stainless steel bracket you see below inside the fuel cell.
Then the external pumps are a Quantum 044 style pump feeding the direct injection OEM fuel system and a MagnaFuel 525 gear-driven pump feeding the port injection fuel system.
So why the big change? Well, there are a few reasons really:
With the AWD swap, I couldn’t retain the OEM fuel tank due to the mid-driveshaft so I had to find a new solution. There is some Volvo OEM fuel tank that works with some basic modifications, but this is a racecar. I did not want to retain the same limitations as OEM.
With the power I am pushing and plan to push in the future, I need all the octane I can get so it made sense to use a single tank feeding both DI and PI fuel systems.
Typically, in drag racing, you specifically use a small (less than 3 gallon) fuel cell in the front of the car, much like the CS Fender Fuel Cell. However, my car still sees street use, at events, and may or may not always be a drag racing-only car so I wanted a fuel cell system that could do anything I wanted now and in the future.
Next up is the rear suspension…this is my favorite part…except for the actual AWD of course! With the rear suspension, I am taking a much more unique approach by using an inboard mounting cantilever coilover suspension. While this seems over complicated upfront, and it is, it will also provide me with a lot of flexibility and control later when using and tuning the suspension.
But what’s wrong with the OEM suspension design?
Nothing is “wrong”, it’s just not ideal. The lower control arm that supports the coil spring is very heavy, the OEM damper mount can’t be used due to the driveshaft so I will need to create a new mount elsewhere with cantilever or OEM style suspension and lastly, I want double adjustable (rebound and compression) dampers which would be more difficult and expensive to source that will work in the OEM style arrangement.
All of those factors lead me to the path of developing my own suspension setup.
Doing some research I found QA1 dampers have great reviews, are very cost-effective, come in many different sizes/lengths, and have double adjustable options. They seem very fitting for my goals.
The double adjustable control is important for any type of competitive racing, but with drag racing, I had a specific need. When the car is launched from a standstill, there is an extreme amount of weight transfer happening that needs to be allowed to “transfer” to the rear but then needs to be controlled and maintained in that position.
Lastly, what is this cantilever suspension and what does it look like? Here’s a teaser of my design.
While I am planning to dig into the design around this in more details, that will have to wait til the next blog in this series. In a nutshell, the outboard suspension that the wheel and tire is connected to pushes a “push-rod” to a larger rocker arm (cantilever) that then pushes a coilover damper and spring setup. Other than the rod itself, this entire system is inside the car between the rear damper towers.
I hope you are enjoying this series about the AWD Swap Mazdaspeed3, stay tuned for more blogs to come!
You likely already invested in our SRI and rear sway bar, but if you are looking to further enhance the driving characteristics of your Mazda, the CS Camber Plates are a great mod to add to your build. Whether you want to fine-tune your setup for the track or you are looking to upgrade to a more aggressive wheel and tire combo, the CorkSport Camber Plates will give you the extra adjustability needed. Continue on reading for more details on the CS Camber Plates.
The camber plates are designed to take the place of your factory strut top so that whether you are on lowering springs or factory springs, installation is quick and simple. For previous generation camber plate kits, it was required to cut the top of the strut tower to gain access to the camber plate to be able to adjust it while installed. This is not the case, however, for the 4th GEN Mazda 3 and CX-30! Making camber adjustments is easy and if they ever need to be removed, permanent modification was not required during installation. The Mazda 3 Camber Plates also feature a pillow-ball bearing that replaces the factory rubber mount and makes sure that the strut bar does not move excessively while driving in demanding situations.
Now let’s get to the amount of camber adjustment the CorkSport Camber Plates provide. On the Mazda 3 you can expect camber adjustment ranging from -2.4 to +0.9 degrees. There is a noticeable difference between the two, so if you are looking to fit a more aggressive wheel and tire combo the camber plates may help you achieve it without rubbing the paint off your fenders. The camber adjustment will also help if you plan on tracking your car or want to fine-tune your setup to your driving style on the backroads.
Finally, let’s go over the construction of the CorkSport Camber Plates. The camber plates feature a top and bottom plate. The top plate houses the adjustment slots for the lower plate and is made out of 6061-T6 aluminum that is then CNC machined. The lower plate features the pillow-ball bearing and is manufactured out of steel to provide the necessary strength needed to secure the strut in place so it does not move during hard driving. Also included with the CS Camber Plates is all the necessary hardware so you can get back out on the road to find your optimal camber setting quickly.
The CorkSport Camber Plates are a great mod to continue to enhance the handling performance of your Mazda 3 or CX-30 and also if want to build upon the aggressive appearance at the same time. Be sure to check out the website for additional photos and video on the camber plates and feel free to contact us with any questions you might have.
