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GREDDY TRUST Comfort Sports GT Slash Exhaust System for Mazda RX8 (Series 1, 2003-2008)

Stainless cat-back exhaust made in Japan, tuned to 92dB for a genuine sporting note with minimal cabin drone on the daily commute or back-road run.

$1,800

Only 3 left!

In stock

The RX8 GT Slash exhaust is a Japanese-made, fully stainless cat-back system built specifically for the SE3P chassis. GREDDY TRUST engineered it around a single brief: deliver real sporting character without turning every commute into an endurance test. Measured at 92dB against the OEM system’s 84/85dB, the step up in volume is deliberate and controlled.

Pipe diameter runs 60mm dual-path with a 102mm outlet. Minimum ground clearance is maintained at 170mm at the intermediate pipe section, keeping it practical on a road car.

RX8 GT Slash Exhaust System Features

  • Full stainless steel construction, buffed to a high finish, gives this system lasting durability and a polished look that suits the SE3P’s character.
  • The 60mm dual-pipe layout and 102mm outlet diameter support free exhaust flow from the Renesis without excessive back-pressure. The result is sharper throttle response from low in the rev range.
  • A large-format silencer manages resonance deliberately. Cabin drone stays minimal across a wide rpm range, so longer drives remain comfortable.
  • The tail tips carry a titanium heat-gradation finish. It develops colour naturally with use, shifting through gold and blue tones as heat cycles accumulate.
  • Finally, 170mm minimum ground clearance at the intermediate pipe means the system is genuinely road-car practical. It is not a track-only compromise on standard ride height.

For RX8 enthusiasts, the difference this GT Slash exhaust delivers is most obvious as the Renesis builds revs toward the redline. The note sharpens into something with real presence, and the throttle feels more immediate and direct.

Back in traffic, the large silencer does its job. The cabin stays relaxed, and the system never grinds on a long motorway stretch. The titanium tips darken with each heat cycle, a constant visual reminder that this is not a generic stainless cat-back.

The GP SPORT Exas High-flow Power Catalyser is the natural companion upstream, it keeps emissions equipment working while clearing the path this RX8 GT Slash exhaust rewards. The GREDDY TRUST Oil Filter keeps the engine side consistent with the same brand’s engineering standards. Full specifications are available on the GREDDY TRUST official site.

Additional information

RX8 Model

Colour

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SKU GT-EXT-S1S2 Category Types , Brand:

Related RX8 Upgrades

This gt slash exhaust system is one of the best Mazda RX-8 upgrades you can make to your Series 1 (2003-2008). Cat-back exhaust systems are among the top Aftermarket mods you can buy from GREDDY TRUST for owners who want better performance and reliability from their RX8. If you are looking for rx8 cat-back exhaust for sale in Brisbane (QLD), Sydney (NSW), Melbourne (VIC), Canberra (ACT), Adelaide (SA), Darwin (NT) or Perth (WA), you’ll find high-quality Japanese Exhaust upgrades at RX8 Upgrades.

Frequently Asked Questions

Which RX8 models does the GREDDY TRUST GT Slash exhaust fit?

The GREDDY TRUST Comfort Sports GT Slash is designed for Series 1 RX8 models, covering the 2003 to 2008 build years. If you have a Series 2 RX8, you will need to check whether a separate Series 2 fitment is available.

Is the GT Slash cat-back system too loud for daily driving?

Store owner Josh has run the GT Slash personally and describes it as sporting but restrained. Cabin drone is minimal, with little to no intrusive resonance on longer road drives, making it a genuine daily driver option rather than a track-only system.

How does the GT Slash compare to the AUTOEXE cat-back exhaust?

Based on Josh's first-hand experience with both systems, the GT Slash sits a step above the AUTOEXE in aggression and character. Build quality and fitment are rated as outstanding on both, but the GREDDY TRUST unit delivers a more pronounced sporting note while remaining civil enough for everyday use.

What type of piping does the GT Slash system use?

The GT Slash uses mandrel-bent piping, which maintains a consistent internal diameter throughout the system. This supports smooth exhaust flow from the Renesis engine through to the tips, avoiding the flow restrictions that can occur with crush-bent alternatives.

Will I notice a difference in throttle response after fitting the GT Slash?

Josh reports a noticeably sharper throttle response and a stronger sensation of torque through the mid-range compared with the stock exhaust system. The difference is most obvious during a spirited drive as the Renesis climbs toward the redline.

What do the exhaust tips look like on the GT Slash?

The GT Slash features titanium-style tips that give the rear of the RX8 a serious, sporty finish. They suit the car's lines naturally and are a genuine visual upgrade over the standard OEM outlets.

Is the GT Slash a cat-back or a full turbo-back system?

The GREDDY TRUST GT Slash is a cat-back system, meaning it replaces the exhaust from the catalytic converter back. The catalytic converter itself remains in place, which keeps emissions equipment intact.

What other parts pair well with the GT Slash exhaust?

A high-flow catalytic converter fitted upstream complements the GT Slash well, supporting freer exhaust flow while keeping emissions equipment in place. The GREDDY TRUST Oil Filter is also a natural companion if you want to keep the engine bay tidy with matching brand hardware.