Audi S4 / S5 Stage 1 & Stage 2 Tuning

Audi S4 / S5 Stage 1 & Stage 2 Tuning – Expert ECU Remaps at Our Workshop

Audi S4 / S5 Stage 1 & Stage 2 Tuning

The Audi S4 and S5 are renowned for their refined power and Quattro all-wheel-drive grip, but with our Stage 1 and Stage 2 ECU remapping in Slough, you can transform their performance to a whole new level. We specialise in safe, reliable, and precision-engineered tuning that delivers more power, sharper throttle response, and a thrilling driving experience, while retaining everyday usability.

Our Stage 1 ECU remap is the perfect first step for unlocking hidden performance from your S4 or S5. Without requiring any hardware changes, we optimise boost pressure, ignition timing, fuelling, and torque delivery for significant gains in both horsepower and torque. The result is a car that feels instantly faster, more responsive, and even more engaging to drive – whether cruising the motorway or pushing hard on back roads.

If you’re looking for maximum output, our Stage 2 ECU remap combines our advanced software tuning with essential performance hardware upgrades such as a high-flow downpipe, uprated intercooler, and performance intake system. These components improve airflow and cooling, allowing us to safely push the engine further and deliver even greater power gains without compromising reliability.

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Why Choose Onyx Performance?

As Seen on Carwow

We’ve been proudly featured on Carwow – a testament to the quality, professionalism, and performance-focused results that set us apart. Watch our feature here to see us in action.

Expertise You Can Trust

With years of experience and deep technical knowledge, our team understands performance vehicles inside and out – from custom remaps to high-end servicing.

Advanced Workshop & Tools

We operate from a state-of-the-art facility in Slough, equipped with cutting-edge diagnostics, dyno testing, and industry-leading tools for accurate, high-quality work.

Tailored Solutions for Every Vehicle

We don’t believe in one-size-fits-all. Every car gets a bespoke approach, ensuring the best results whether it’s a remap, upgrade, or routine service.

Trusted Nationwide

Performance enthusiasts from across the UK come to Onyx because they know they’ll receive premium-quality workmanship, careful attention to detail, and honest advice.

Complete Care, All in One Place

From tuning and servicing to tyres, trackers, and immobilisers – we offer a full suite of services under one roof, all with a strong focus on safety, reliability, and top-tier customer support.

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Book Your Audi S4 / S5 Stage 1 or Stage 2 ECU Remap in Slough

Experience the full potential of your Audi S4 or S5 with our expert Stage 1 and Stage 2 ECU remapping services. From software-only upgrades to hardware-supported Stage 2 builds, we deliver precise, safe, and powerful results. Contact us today to schedule your remap at our Slough workshop.

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Why Choose Onyx Performance for Servicing?

Experts in Performance Cars

We know how to properly care for performance, modified, and luxury vehicles. Our team has the skills and experience to handle specialist requirements confidently.

Correct Service Schedules

Every service follows the exact schedule recommended by your vehicle’s manufacturer, helping maintain performance and protect your warranty.

Quality or OEM Parts

We only use high-quality aftermarket or original manufacturer parts, ensuring long-lasting reliability and top-level performance.

Full Vehicle Inspection

Our service goes beyond just changing oil. We inspect all key systems to keep your car safe, smooth, and road-ready.

Honest Advice, No Surprises

With transparent pricing and expert recommendations, you’ll always know what your car needs – no upselling, no hidden fees.

Fast, Trusted & Tracked

We offer quick turnaround, maintain service records, and send reminders – that’s why customers travel to us from across the UK.

Frequently Asked Questions

How much power can Stage 1 add to my S4 or S5?

Stage 1 typically delivers 40–80 bhp gains, depending on the model and fuel quality.

Is Stage 1 safe for my standard engine and components?

Yes – Stage 1 is designed to work within factory safety limits without reducing reliability.

What’s required for Stage 2 tuning?

Stage 2 requires performance parts such as a sports downpipe, upgraded intercooler, and performance intake system.

Will tuning affect my fuel economy?

With sensible driving, many owners find fuel economy stays the same or improves due to the more efficient tuning.

Can the ECU be returned to stock later?

Yes – we can restore the original factory calibration at any time.

Do you provide dyno testing?

Absolutely – we offer before and after dyno runs so you can see your exact performance gains.

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