Turbo Back Exhausts

A turbo-back exhaust replaces everything from the turbo outlet to the tip, so it's the biggest single breathing change you can make to a turbo-diesel without going inside the engine. The PPD systems on this page are PPD's own range, built to one spec across the catalogue, with vehicle-specific fitment for popular diesel utes and wagons like the Hilux, D-MAX, BT-50, Navara, Ranger and the 100 Series. We design and fit these in our Perth workshop, so the fitment questions you'd ask across a 4WD counter, we answer here. You can browse the full turbo-back exhaust range below, or read on to choose correctly first.

What Is a Turbo-Back Exhaust and What Does It Do?

A turbo-back exhaust is the section of exhaust that runs from the turbocharger outlet all the way to the rear tip. That covers the dump pipe, any cat or DPF section, the centre pipe and the rear muffler and tip. Because it replaces the whole hot-side path, it does more than a muffler swap.

On a turbo-diesel, a wider, smoother turbo-back exhaust does three things. It lets exhaust gas leave the turbo with less back-pressure, which helps the turbo spool and breathe. It reduces exhaust gas temperatures (EGT) under load, which matters on long climbs or when towing. And it gives the engine a freer-flowing path overall, which is the foundation for any further tuning work. The note gets deeper too, but on our range the construction is the point, not the volume.

What Makes PPD's Turbo-Back Exhaust Different?

PPD's turbo-backs are PPD's own systems, not a resold catalogue line. Every PPD turbo-back system in this range is built to the same verified spec:

• 304-grade stainless steel piping, for corrosion resistance that suits coastal and outback use.
• 1.5 mm wall thickness, so the pipe stands up to underbody knocks and heat cycling.
• Mandrel-bent, so the bore stays a true diameter through every bend instead of being crushed down where it turns.
• TIG-welded joints for clean, consistent welds.
• A 1/8 NPT EGT probe port already in the system, so you can fit an exhaust gas temperature gauge sensor without drilling and tapping the pipe yourself.
• A complete fitting kit with the gaskets, bolts and clamps needed to fit it where required (factory hangers are reused).

That last point matters at fit-up time. You're not chasing gaskets and hardware on the day. Examples from the range include the Toyota Hilux D4D KUN N70 3" turbo-back, the Isuzu D-MAX 4JJ3 3" turbo-back and the Mazda BT-50 4JJ3 3" turbo-back, which shares the same motor as the current D-MAX.

Why Is 3 Inch the Right Size for Most Diesel Turbo-Backs?

3 inch is the dominant diesel turbo-back size for a reason. It flows enough to clear the exhaust gas a modern turbo-diesel produces, including once the engine is tuned. For the vast majority of 2.8L to 4.5L diesel 4WDs and utes, a 3" turbo back exhaust is the sensible match between flow and drivability.

Going smaller, like 2.5", limits flow on a tuned engine and gives away EGT headroom. Going larger than 3" is only offered on very limited models (79 Series and D-Max), and a bigger bore doesn't hurt low-down torque on a turbo-diesel. For most owners the 3" stainless turn-key system on this page is the right call.

Is a 3-Inch Turbo-Back Exhaust Loud?

A mandrel-bent 3" turbo-diesel system is noticeably deeper than the factory exhaust, but a diesel doesn't produce the high-rpm note a petrol does, so it's a low-frequency rumble rather than a scream. With the muffler retained, most owners find it pleasant on the open road. Some highway droning at certain rpm is possible, as it is with any larger system. If quiet cruising is your priority, tell us and we'll talk through muffler options (straight-through, resonated or muffled) before you order.