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My name is Jak Brittain and I own a small fabrication workshop named Metal Sculpt, located in Brisbane Australia. I specialize in custom exhaust setups and upgraded components for rotary engine powered vehicles. I've owned and modified Rx-7's for over 15 years now, and first started tig welding/metal fabrication as a side business in 2019. I mainly learnt from completing fabrication work on my personal Rx-7 project, H8PSTN (build thread in the 1st Generation Archives), and from working at a performance fabrication workshop in Sydney named Westside Mufflers. The FD3S Rx-7 is one of my favourite cars, I work on them more than any other platform by a significant margin. The Artec T4 turbo manifolds are very popular in Australia, and a great option for those who don't want the added costs and complexity of a twin wastegate manifold. Almost every FD that came through the workshop in 2025 was running one, so I decided to develop a bolt-on exhaust system to suit.
System Information:
The exhaust system is constructed from 3.5" 304 stainless steel from the turbine outlet to the exhaust tip. This is a distinct advantage over a 3" system, especially on larger turbochargers and at higher boost levels. Larger diameter tubing will lower boost threshold, increase boost response and increase outright power. All sections of the exhaust are assembled on hand-made jigs, which were made using an actual FD3S in the workshop as a reference.
The sections of tubing are CAD modelled, and laser cut using a CNC tube laser. This means that repeatability is enhanced over cutting out each section manually using bandsaws or similar- this has the added benefit that all weld joints are perfectly clean prior to welding. When prepping exhaust tubes using manual machines, tools such as bandsaw blades, linishing belts, angle/die grinders and hand files will all deposit impurities into the weld joints, leading to a weaker weld.
X-Force polished stainless steel mufflers and resonators are fitted as standard. These mufflers have been tested in my own personal Rx-7 over a 4 year period. They have a great exhaust note and aren't too loud for long drives. The test vehicle runs a bridge-ported 13B Turbo, using both 93 octane and E85 fuel. It has run up to 26psi boost and regularly uses a rev limiter and two-step for drag racing (hard on mufflers), with no noticeable degradation.
There is multiple options for fitment- I can make the systems to suit recirculated wastegates or screamer pipes, catalytic converter or de-cat, and either v-band or 3" 2 bolt outlets for those on a budget or to join to an existing system. Pricing for each configuration is available on our website, and customizable to suit your individual needs using drop down menus on the product page.
Important Notes and Recommendations:
The factory mid brace needs to be spaced down slightly, or removed to fit the 4.5" diameter resonator. Spacers are supplied in the kits for this purpose- alternatively a replacement 3D printed aluminium mid-brace is available for purchase on the website, which gains the necessary exhaust clearance without compromising ground clearance.
If your turbocharger isn't listed and you'd like a system made, two options are available. I can model the downpipe using 3D scans of your turbine housing for a design fee, companies such as Turbosmart have sent model files happily on past jobs. Alternatively I can supply just the mid and rear pipes, with a V-band inlet that your fabricator can use when making a down-pipe locally. This is a perfect option for those who want to run the exhaust with a different manifold/turbo aswell.
For outright power I recommend screamer pipes and no catalytic converter. This will increase noise under boost when the wastegate opens, and may make passing emissions/smog testing difficult for those living in states where this is required.
