Custom Performance Engineering Parts

What are the best performance parts for a Mazda Mazdaspeed3 or Mazdaspeed6? For these turbocharged Mazda platforms, Custom Performance Engineering — better known as CP-E — is one of the best-known specialists: its catalog is built around reinforced engine and differential mounts, high-flow downpipes, gauge pods, and stainless exhausts, all engineered to fix the weak points of aging performance Mazdas. The line also extends to the Subaru WRX, with driveline mounts and an axle-back exhaust.

Mazdaspeed3 and Mazdaspeed6 cars are now well into their service lives, and the factory wear items show it. Soft stock motor and differential mounts let the drivetrain rock under load, which means wheel hop, sloppy shifts, and eventually torn mount rubber. The factory downpipe is a restriction on the turbo's hot side, and the stock exhaust does these engines no favors. CP-E's answer is an engineering-first parts line: the xFlex™ series of reinforced mounts for motors and differentials, QKspl™ downpipes for the Mazdaspeed3, triple gauge pods for monitoring boost and vitals, and the Austenite™ stainless exhaust line — each designed to solve a specific platform problem rather than just look the part.

Custom Performance Engineering (CP-E) built its reputation in the Mazda Mazdaspeed community, and it shows in the catalog's depth: xFlex™ rear differential mounts for the Mazda Mazdaspeed6, xFlex™ motor mounts for the Mazda 6s, QKspl™ catted downpipes for the Mazda Mazdaspeed3, and triple gauge pods for the Mazda3 and Mazdaspeed3 all target the parts these cars actually need. The brand's engineering-first approach shows in its product naming and construction — reinforced, platform-specific, and built to last. The line has since expanded to the Subaru WRX, including a pitch stop mount and an Austenite™ off-road axle-back exhaust for the 2015-2021 WRX. If you own a Mazdaspeed or a WRX, this is a catalog worth browsing part by part.

Mounts, downpipes, and exhausts work best as part of a complete plan. Browse performance engine mounts for the full mount selection, check performance intercoolers, or compare turbo specialist COBB. Standout CP-E pieces include the xFlex™ rear differential mount for the Mazda Mazdaspeed6, the QKspl™ catted downpipe for the Mazda Mazdaspeed3, and the pitch stop mount for the Subaru WRX. Building a Mazda performance plan? Our top aftermarket parts for the Mazda RX-7 post has useful perspective on Mazda performance builds.

Will stiffer mounts make my car vibrate more?

Some increase in noise and vibration is normal with reinforced mounts — that is the trade-off for eliminating drivetrain movement and wheel hop. Most drivers find the sharper throttle response and cleaner shifts worth it on a performance car.

Does a downpipe require a tune?

Generally, yes — a high-flow downpipe changes exhaust flow enough that a tune is recommended to keep the engine safe and realize the power gains. Check the product details and talk to your tuner before installing.

Will CP-E parts fit my year and model?

Fitment is platform-specific — Mazdaspeed3, Mazdaspeed6, Mazda 6s, and specific WRX years each have their own parts. Check each product's title for the exact fitment and check your year and model before ordering.

What does "off-road" mean on the axle-back exhaust?

An off-road exhaust is intended for off-highway or track use rather than street driving, usually because it lacks street-legal emissions or noise certification. Check your local regulations before using it on public roads.