The next generation of Miata turbocharger systems
back to FM turbos

While we had worked to refine the old designs for years, they weren't completely satisfactory. Over the course of 2006 we reworked our turbocharger systems using modern CAD technology.We knew we could improve the function of the parts while using much more accurate production techniques and better materials. As an added bonus we should be able to bring the quality and performance up while reducing prices. Dan Bond, an experienced aerodynamicist and member of the original Ubercharger design team, worked closely with FM to add his knowledge and expertise to our new designs. There aren't any other companies out there with both our long experience with Miata turbocharging and deep understanding of engine management.

The manifold was designed with a close eye to internal airflow. We did all the design work in SolidWorks and then had a plastic version made on the world's coolest 3D printer. When this piece was offered up to a cylinder head, it fit perfectly the first time out and there was enough room to put a box wrench on every nut on the manifold. We also retained the turbo mounting location we have used for years so it can be retrofitted to existing kits.

The turbine outlet housing is also compatible with older kits. It looks a little odd, but allows us to have a divorced wastegate exhaust to smooth out airflow at the turbine outlet and keeps the two air streams separated right from the start. There's no complex and error-prone fabrication required, it simply bolts into place. This improves reliability as well as accuracy. As with the manifold, careful attention was paid to ease of installation.

The intercooler hoses are primarily made of Nomex-reinforced formed silicone. We pushed the manufacturer to expand their production capabilities for a couple of the pieces. The advantage to the silicone is that it is lighter than steel pipes, eliminates a large number of joints (and potential failure spots) and is easier to install. It also cuts down on NVH transmission to the car body. Like all of our silicone interconnects, the pipes have a grippy interior to make blown-off hoses a thing of the past.

Even the oil and water hose heat shielding underwent some examination. We moved to a slip-on heat shielding material instead of the sheet we'd used before, making for much easier installation.

We also worked outside the shop. All the test cars were subjected to dyno runs, long road trips and full-on track testing with ambient temperatures well above 100F.

The end result? Gain in efficiency and power, less backpressure, easier installation and lower prices on the kits.

Dyno chart
This is our previous FM II compared with the redesigned unit. Both cars have stock internals, FM turbo exhausts and are running the Link ECU on 91 octane fuel. Both turbos are set at 12 psi.

Photos (newest at top):

 Testing on the track.
 Checking dimensions on the final prototypes.
 The final outlet casting.
 A raw casting versus a finished unit. The machining is done by CNC to ensure consistency.
 From CAD to rapid prototype to metal. A test casting (grey) compared to the plastic version. It was cast using a less accurate process than the final and is not made of NiResist, but the important dimensions are the same. Final pieces will have a much nicer finish and will not be grey!
 The final CAD model for the exhaust manifold. The individual runners can be clearly seen.
 We paid attention to internal flow.
 We also paid attention to installation, ensuring there is room for fasteners wherever necessary.
 The CAD modelling process allows us to peek inside the manifold to ensure everything worked well.
 The manifold has been designed to allow fitment of an external wastegate if desired.
 Our rapid prototypes allow us to ensure the digital models work well with reality.
 There are some small details that don't show up well on models. That's why we invested in the rapid prototypes.
 The two air channels are carefully managed in the turbine outlet housing.
 The protrusion on the housing is to seal the wastegate stream from the turbine outlet. This ensures minimum turbulence and maximum efficiency without the packaging hassles of an oddly-shaped downpipe such as the one we investigated on our racer.
 A detail you don't appreciate unless you've tried to install a part without it - clearance for tools.
 A peek at the rapid prototype. This was made from an earlier model with a shorter divider.