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

Price range: £489.22 through £797.88

The ASM Performance Toyota Supra GR 3.5″ stainless steel downpipe.

Warranty

All ASM Sports Tech components are produced using motorsport-grade materials and manufacturing standards same as OEM.

Our components are covered by an 12-month to lifetime structural warranty, depending on the component and usage conditions. Full warranty details can be viewed on our warranty page.

Shipping

  • – Orders for in-stock items placed before 20:00 GMT are despatched the same day.
  • – Free UK delivery on all orders.
  • – Worldwide shipping availalbe.
  • – Fully tracked couriers services.

Returns

At ASM Sports Tech, every component is developed with precision and quality control.

If for any reason you are not satisfied with your purchase, returns or exchanges can be arranged within 14 days of delivery.

Please visit our Returns Page for full details.

All ASM Sports Tech components are supplied with installation hardware where required.

For optimal fitment and performance, proffesional installation is strongly recommended.

All our carbon fibre components are produced with OEM-level tolerances.

Some ASM Sports Tech components are handcrafted to order.

– In-stock items are despatched immediatly.

– Made-to-order components typically require 2-6 weeks production time.

If a product is temporarily unavailable, our team will contact you within 24 hours to confirm production timing or offer available alternatives.

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CONFIDENCE PROGRAMME

Every ASM Sports Tech component is developed and inspected under our Confidence Programme, ensuring verified materials and trusted ownership support.
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OEM PRECISION FITMENT

Engineered using 3D scanning and digital modeling to achieve factory-level fitment and seamless integration with each vehicle platform.
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PERFORMANCE ENGINEERING

Lightweight composite construction combined with structural rigidity to enhance aerodynamic performance and visual presence.

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.

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