Toyota Supra A90 Front Downpipes – Sports Cat / Decat Version for B58 Engines

Toyota Supra A90 Front Downpipes

Unlock the full potential of your Toyota Supra A90 with the ASM Performance Front Downpipes for the B58 engine. Available in both sport cat and decat versions, these precision-engineered downpipes are designed to deliver maximum performance gains while maintaining OEM fitment.

Constructed from high-grade stainless steel, the downpipes significantly improve exhaust flow, reduce back pressure, and provide a sharper, more aggressive exhaust tone. The sport cat version offers enhanced flow while retaining emissions compliance, while the decat version maximises performance and turbo spool for track-focused builds.

Key Features:

• Designed for B58 Engine – perfect fit for Toyota Supra A90.

• Sport Cat or Decat Options – tailored for street or track use.

• Performance Gains – improved turbo spool, power, and response.

• OEM Fitment – precision CNC-machined for direct installation.

• Aggressive Exhaust Tone – sharper, motorsport-inspired sound.

Take your Toyota Supra A90 to the next level with ASM’s B58 Downpipes – built for power, precision, and performance.

What is the difference between a sport cat and a decat?

Sport Cat Downpipes

Catalytic Converter Included: Sport cat downpipes include a high-flow catalytic converter. This helps reduce exhaust emissions while still allowing for increased flow compared to standard catalytic converters.

Emissions Compliance: They are designed to be street-legal in many areas, as they still filter harmful emission, though regulations can vary by region.

Performance: Sport cat downpipes strike a balance between performance and emissions compliance. They offer a noticeable increase in horsepower and torque compared to stock downpipes, but might not be as free-flowing as decat downpipes.

Sound: The sport cat downpipes provide a moderate increase in exhaust sound over the stock system.

Decat Downpipes

No Catalytic Converter: Decat downpipes eliminate the catalytic converter entirely, resulting in zero filtration of exhaust gases. 

Higher Performance: They allow for maximum exhaust flow, which can result in significant performance gains, particularly for turbocharged engines.

Emissions Non-Compliance: Decat downpipes are typically illegally for street use in most regions due to their complete lack of emissions control. They are generally indented for track use or off-road racing.

Emissions Non-Compliance: They produce a louder and more aggressive exhaust note.

The de-cat exhaust version is available for motorsport and off-road use exclusively worldwide.