Best GR Supra Mods: Stage 1 & Stage 2 Upgrade Guide (Australia)

The Toyota GR Supra A90/A91 is one of the best cars you can buy to modify. Its BMW-built B58 3.0-litre turbo six is strong, has plenty of headroom and responds very well to a few well-chosen parts. The hard part is knowing where to start. This guide explains what Stage 1 and Stage 2 mean on a GR Supra, which parts are worth your money, and what each stage costs in Australia, with the AUD prices we sell at.

What do "Stage 1" and "Stage 2" mean on a GR Supra?

There's no official rulebook, but the Supra community mostly uses these terms:

• Stage 1: an ECU tune on otherwise stock hardware, often with a bolt-on intake. It's the best power-per-dollar mod you can do on a B58.
• Stage 2: a tune written for a downpipe, usually with an intake and better cooling as well. This is where the B58 really starts to pull, and where turbo response and sound change the most.
• Beyond Stage 2: ethanol (E30–E85) blends, port injection, upgraded charge cooling and eventually turbo upgrades. This is serious build territory.

Step zero: unlocking the ECU

Before any tune can be loaded, the Supra's ECU (DME) has to be unlocked. Which unlock you need depends on when your car was built:

• Pre-06/2020 Supras: a bench unlock ($400) opens the ECU to flash tuning with MHD and Bootmod3.
• 06/2020 and later (MG1 ECU): these are locked from the factory and need our FEMTO ECU unlock ($1,680). It's permanent, it survives dealer software updates, and it gives full access to MHD, Bootmod3, EcuTek and MG Flasher. Shipping to and from our workshop is included.

Not sure which one your car needs? See our ECU unlock and coding services, or read about ECU unlock and tuning in Melbourne.

Best Stage 1 GR Supra mods

1. ECU tune

Once the ECU is unlocked, a Stage 1 map makes the biggest single difference. Boost, timing and throttle response all improve, and the car pulls noticeably harder through the mid-range. The same platforms also let you adjust burbles, cold-start behaviour and transmission settings.

2. Cold air intake

An intake is the natural partner to a tune. It improves airflow, sharpens throttle response and adds that addictive turbo flutter. Popular choices we stock:

• MST Performance Intake V3 ($999): 6" aluminium tube and 4" pod filter. MST quotes 12–14 hp on a stock tune with no check engine light.
• Injen EVO2300 ($830): a sealed-box design that keeps hot engine-bay air out.
• ARMASPEED carbon fibre intake ($1,499) and AWE S-FLO carbon intake ($2,050), for a factory-look carbon finish.

Compare every option in our GR Supra cold air intake collection.

3. Cat-back exhaust (optional)

A cat-back won't add much power on its own, but it changes how the car feels to drive. The Valvetronic Designs valved exhaust (from $4,400) lets you switch between quiet and loud. The AWE Touring Edition (from $5,050) stays refined on the freeway. The RSE titanium Type-R ($2,800) is lightweight and raw. See all our GR Supra exhaust systems.

Best Stage 2 GR Supra mods

4. Downpipe

The downpipe is the part that defines Stage 2. The factory unit has a dense, restrictive catalytic converter. Replacing it with a 4.5" high-flow pipe cuts back pressure, speeds up turbo spool and unlocks the more aggressive Stage 2 maps. For road cars in Australia, choose a catted downpipe:

• VRSF 200-cell catted downpipe (from $990): the best-value catted option.
• Armytrix 200 CPSI sport cat downpipe (from $1,990).
• Active Autowerke Signature GESI catted downpipe ($2,890): 400 CPSI GESI cat, no check engine light.
• AMS Street downpipe with GESI cat ($3,199) and HKS Metal Catalyzer ($3,299).

Still deciding between catted and catless? Read our guide: GR Supra downpipe: catted vs catless in Australia. You can also browse every GR Supra downpipe we sell.

5. Cooling: heat exchanger and radiator

More boost means more heat, and heat soak is what makes a tuned Supra lose power on a hot Australian day or at a track day. The Mishimoto heat exchanger ($1,550) has 31% more core volume than stock and lowers intake air temperatures. The Mishimoto aluminium radiator ($1,600) is the next step if you track the car.

6. Brakes and suspension

With more power, the rest of the car needs to keep up. Endless MX72 brake pads ($785) give strong, fade-resistant stopping on the street and at the track. H&R Sport lowering springs ($750) drop the car about 25 mm at the front and 20 mm at the rear and work with the factory adaptive dampers.

Going further: ethanol, fuel and charge cooling

Once you're past Stage 2, the B58's limits are mostly fuel and heat. A Radium port injection fuel rail kit ($1,480) gives the fuel headroom for high-ethanol blends. The CSF charge-air cooler manifold ($8,300) is the serious fix for intake temperatures on big-power builds.

The right order to mod a GR Supra

A common mistake is buying parts in the wrong order and paying for a tune twice. Here's the order we suggest to most customers:

1. Unlock the ECU (bench or FEMTO, depending on build date).
2. Fit the hardware you plan to keep: intake, and a downpipe if you're going to Stage 2. Doing it together means one tune session, not two.
3. Tune to suit the hardware: a Stage 1 map for an intake-only car, or a Stage 2 map with a downpipe.
4. Add cooling if you drive hard in summer or go to track days.
5. Upgrade brakes and suspension so the chassis keeps up with the engine.
6. Exhaust last if it's mostly for sound. A cat-back is great for character, but it doesn't need to come before the parts that make power.

Common GR Supra modding mistakes

• Fitting a downpipe without a tune. The ECU will see the change, and you can get fault codes and a check engine light. Always pair a downpipe with a matching map.
• Going catless on a road car. It's illegal on registered cars in Australia and can mean fines or a defect notice. High-flow catted pipes give you most of the gain.
• Ignoring heat. A tuned B58 that heat-soaks on a 35°C day loses power quickly. The heat exchanger is money well spent.
• Cheap, unbranded parts. Poor fitment, leaking flanges and sensor issues can cost more to fix than you saved. Stick to proven brands.

What does a Stage 1 or Stage 2 Supra cost in Australia?

• Stage 1 (unlock + intake): about $1,230 (pre-06/2020 bench unlock plus Injen) to $2,679 (FEMTO unlock plus MST V3), plus the tune itself.
• Stage 2 (add a catted downpipe): add $990 to $3,299 depending on the brand, plus the Stage 2 map.
• Recommended extras: heat exchanger ($1,550), brake pads ($785), springs ($750).

We fit all of this at our Melbourne workshop. See GR Supra install services in Melbourne.

Frequently asked questions

Is a Stage 1 tune safe for a daily-driven GR Supra?

Yes, as long as the tune is from a reputable platform and tuner. The B58 handles Stage 1 boost levels well on factory internals. Keep up with servicing and use quality 98 RON fuel.

Do I need a downpipe for Stage 2?

Yes. Stage 2 maps are written for a less restrictive downpipe. Running a Stage 2 map on the factory downpipe isn't recommended.

Does my Supra need a bench unlock or a FEMTO unlock?

Cars built before 06/2020 can use the cheaper bench unlock. Cars built from 06/2020 have the locked MG1 ECU and need the FEMTO unlock. Check your build date on the compliance plate, or ask us.

Will mods void my Toyota warranty?

A dealer has to show that a modification caused the fault before refusing a warranty claim, but tuning in particular can make claims harder. Talk to us about your situation before you modify a car that's still under warranty.

Is a catless downpipe legal in Australia?

No, not on a registered road car. Removing the catalytic converter breaks emissions rules in every state. For street cars, use a high-flow catted downpipe.