Project FD RX7 Restomod: Part 27 – Fabricating the Exhaust with Vibrant Performance and SP Mufflers

The SP Muffler’s 3.5” FD RX-7 Resonator turned out fantastic with the Vibrant Performance 304 stainless steel tubes, V-band clamps, and 3.5” Bellows.

The rear mounting bracket worked great and holds the muffler in place with the front bracket.  This ensures the heavy mufflers are well-supported and do not generate a pulling force on the exhaust system, turbo, or exhaust manifold.

Between Mario and SP Mufflers, the entire exhaust system of our FD is looking really good.

Mounted on the car, we took a lot of pride in the finished product.  The little details like clearancing to components, maintaining the same plane as the bottom of the car, mounting the mufflers so other components can be serviced, or so that the mufflers themselves can be swapped out if needed, makes the entire exhaust system quite modular and flexible for whatever the future might hold.

Now that the exhaust system is complete, it is time to insulate.  Exhaust insulation is one of the most overlooked and underappreciated components of a car build.  When it comes to turbocharged cars, rotaries, and especially turbo rotaries, thermal management and insulation makes a substantial difference in performance and reliability.  We covered Turbosource’s Inconel intake and exhaust manifold heat shielding in Part-26.

For the exhaust, we are using Heatshield Products Armor in order to keep the heat inside the exhaust and keep the exhaust energy up all the way out to the back of the car.  Thermally insulating the downpipe and exhaust will also greatly reduce temperatures in the engine bay and inside the cabin of the car.

HeatShield Armor has a flexible aluminum outer skin and uses either 1/4” or ½” thick thermal insulation made from fire retardant BioCool™ -a bio-soluble silica that directly contacts and encases the exhaust pipe to reduce up to 70% of radiant heat.  Armor’s insulation is rated to 1,800*F continuous and 2,200*F intermittent and can be affixed with safety wire, hose clamps, or the thermal-ties.