We are developing a vehicle-specific ZF 8HP conversion for the Mazda MX-5 NA and NB. Our goal is not just an adapter solution, but a complete and reproducible package encompassing installation, drivetrain, electronics, cooling, and operation.
The main components have now been designed and produced. The next phase involves functional assembly and road testing.
From digital dimensioning and CAD to physical prototypes and practical tests.
We scan the chassis and transmission to accurately capture mounting points, available space, and critical clearances. The scan data forms the basis for the CAD design of the vehicle-specific parts.
With 3D-printed and temporarily produced parts, we check fit, assembly sequence, and accessibility before the final parts are milled or laser cut.
The complete drivetrain is physically mounted to check alignment, ground clearance, driveshaft, exhaust clearance, cooling, and electronics as one system.
The original MX-5 gearbox can become a limiting factor in high-power turbo projects. The ZF 8HP45 has a nominal torque rating of approximately 450 Nm and is regularly used above this value in modified applications. The ultimate load capacity depends on, among other things, the condition, control, cooling, and application of the transmission.
An automatic transmission makes the MX-5 accessible to drivers who cannot or do not want to shift gears manually. Eight gears also ensure comfortable daily use and lower RPMs during highway driving.
Quick, consistent shifts save time and keep the drivetrain in the desired powerband. With manual control or paddles, the driver can focus entirely on braking, steering, and the ideal line.
Below you will find parts that are currently available separately and can be used in a ZF 8HP conversion. This is not yet the complete LucaCarMods MX-5 8HP swap kit.
This conversion is not just about fit, but about a solution that integrates logically into the MX-5. We retain as many original mounting points for wiring and components as possible, prevent brackets from running over fuel lines or other critical parts, and limit unnecessary rerouting or modification. The result should look OEM-worthy!
The transmission mount had to accommodate the original ZF 8HP rubber mounts, fuel and brake lines, the exhaust, and a future sump guard. To achieve this without unnecessarily relocating existing components, the construction consists of six individually designed parts. This creates a strong, precisely fitting, and easy-to-assemble solution.
The ZF 8HP45/50 barely fits in the transmission tunnel of the MX-5 NA/NB. Because the oil cooler lines run on the same side as the exhaust as standard, we have developed our own adapter that routes the lines up and over the transmission. This creates more space for the exhaust and better protects the lines from heat.
The most common way to operate a ZF 8HP is with an original BMW selector. For this purpose, we have developed a complete mounting solution that fits into the original position in the center tunnel and seals the transmission tunnel neatly at the same time. Solutions for a DCT shifter and CAN keypad will follow later.
The original Power Plant Frame is an important part of the MX-5 drivetrain, as it connects the transmission and the differential, helping to align the drivetrain correctly. With a ZF 8HP conversion, however, a compromise arises: we want to largely retain the supportive function of the PPF, but in our opinion, the 8HP is too heavy to continue to stress the original construction in the same way.
Therefore, we opted for a modified PPF-delete. This removes the rigid connection to the transmission but retains the function of aligning and supporting the differential. The original mounting points for the wiring harness also remain intact.
Compared to many other PPF-delete solutions, this offers neater integration into the chassis, retention of important OEM functions, and less need to relocate existing wiring or components.
To fully utilize all functions of the ZF 8HP, a drive-by-wire conversion is necessary for the Mazda MX-5 NA and NB. For this purpose, we have developed both a pedal adapter and a throttle body adapter.
The throttle body adapter stands out due to its two-piece construction. While many existing adapters position the throttle body at an angle or noticeably off-center, our solution ensures that the throttle body is aligned straight with the intake manifold. This results in a cleaner installation, better fitment, and an appearance that remains as close to OEM as possible.
*In development*
The driveshaft is often one of the biggest hurdles when converting engines and gearboxes. To make this component as simple and reproducible as possible, we are developing our own output flange for the ZF 8HP45. This allows common driveshaft flanges to be used, making the drivetrain easier to assemble and later easier to maintain.
The complete kit comes with a suitable driveshaft designed for torque up to 1,000 Nm. Unlike the original MX-5 driveshaft, this one features greaseable and replaceable universal joints. This allows the driveshaft to be maintained and wear parts to be replaced individually, without having to replace the entire shaft immediately.
As you've read above, we're happy to guide you through the entire development process. For each component, we look for a solution that not only works well technically, but also mounts logically and aligns as much as possible with the original structure of the MX-5.
The main components of the kit have been discussed in broad terms above. In practice, however, each component consists of multiple smaller parts, smart additions, and interconnections with other parts developed by us. Everything is designed as one cohesive system, so that installation, fit, and reliability are not dependent on improvised solutions.
A lot of extra development has also gone into the tuning. For example, options have been built in to precisely optimize the position and angle of the drivetrain. It is precisely these less visible details that ultimately determine how well the conversion fits, functions, and drives.
