1991 Nissan 240SX LE A'PEXi Exhaust

Pros
A'PEXi's N1 system started it all, and it continues to be a standard by which all others are measured. Born from endurance racing technology, the N1 design minimizes the number and degree of bends throughout the system-which means less restriction and more power. For the ExTi variant, A'PEXi replaces the conventional stainless muffler with a lightweight titanium one, which features a removable silencer and variable-length scorched tip. Our system bolted up perfectly to the cat and hangers and featured a drastically larger piping diameter than stock-crucial for forced induction. An integrated oval-shaped resonator managed to keep the exhaust note to a respectable level, while providing adequate ground clearance and maintaining a straight-through design.

Cons
With the exhaust installed, we noticed that part of the piping made contact with a seatbelt bolt protruding from the underside of the car. Asking around, we learned that this wasn't a problem other tuners were experiencing and attributed the miss-fit to the poorly manufactured, generic tubular manifold (Tip: Don't buy knock-off products!). The 240SX exhaust tract doesn't make use of spring-bolts or flex-pipe to compensate for imperfections, so proper construction of every component from the head back is crucial in maintaining proper fitment of all other parts.

Parts
Stainless steel mandrel bent piping with resonator; titanium muffler with silencer, tip and bracket, nuts, bolts, gaskets and stickers.

Tools
12mm ratchet, 12mm open-end wrench; impact wrench, breaker bar and/or WD-40 for loosening 200k-mile-old stock components.

Installation time
17 minutes with two people, a lift and no problems.

Notes
As suspected, replacing the wrinkled Pixy Stix-stock exhaust with the larger, straighter A'PEXi unit netted us some impressive gains. Power and torque fell slightly before 3,000 rpm, due to the reduction in back pressure, but the 5 to 17 whp we picked up above 4,500 rpm more than made up for it. Even without the optional silencer, the N1 ExTi's smooth tone was just perfect for the streets-not the least bit loud or offensive. Be sure to thoroughly soak the stock bolts with WD-40 before loosening them. Use of an impact gun is highly recommended, but you may run into the problem of nuts and bolts being too rusted to grip with any tool-an angle grinder or acetylene torch is the weapon of choice here. Just watch those fuel lines...