Boig Motorsports proudly announces NEW undercar and through the rear 818 exhaust systems. They are designed to fit all Factory Five 818s including those using the latest trunk design.

Under car exhaust systems


818 under car center exit exhaust with twin tip resonator.

These systems are two piece, for ease of installation. There are two choices of upper pipe - one with a Magnaflow catalytic converter, the other with a Quiet Pipes baffled muffler (not a glasspack). There are two lower configurations available. The first is a straight through tube which allows the customer to choose and install custom exhaust tips. The second option is a Monza style glass packed twin tip resonator. Both tips exit under the 818 in the middle of the car. These systems fit both standard and diffuser fitted cars. Both lower pipes clear the underbody by 1-1/4", leaving plenty of room for a diffuser. The bottom of the lower pipes is 3/4" higher than the plane of the frame offering good ground clearance. Either top section will fit either lower section, providing four possible combinations.


818 under car center exit exhaust with convertor

These systems utilize a bell mouth turbo flange, and 2 1/4" 16 ga. (.065" wall) quality
U.S. made tubing. They are mandrel bent, formed, and welded in the U.S. Please note the quality of welds, bends, and forming in the attached pictures.


818 under car center exit exhaust with muffler

The system can be VHT painted, or ceramic coated by the customer. The units are jig built to order and O2 bungs will be located per customer request. Hardware and gasket for attachment of upper to lower section are included.

A support bracket is available which attaches solidly to the transmission. No other support is necessary.


818 turbo under car exhaust with converter and twin tip resonator

For customers interested in the quietest system, that would be the quiet pipes upper with the resonator lower section. Next quietest is the catalytic converter upper with the resonator lower.

In the testing and development of this product, seven mufflers and three converters were evaluated to ensure best performance. Extremely tight room constraints were a major factor, and sound quality and clean design was the goal.


818 turbo exhaust and bell mouth flange

These units are available to order now. Delivery will be 3-4 weeks.

We hope you enjoy the product as much as our four man development and fabrication team enjoyed the challenge!

Click here to visit our website and order.

Click here to order from Replica Parts.

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Boig Motorsports Parts

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View our Quiet Pipes Side Pipe Kits for Roadsters!