What's the difference between MA70 and JZA70?

The chassis code tells you which engine the car was built with. MA70 is the turbo model with the 7M-GTE engine (3.0-litre single turbo, ~230 hp). GA70 is the naturally aspirated model with the 7M-GE (~200 hp). JZA70 is the later Japanese domestic market variant (1990-1993) fitted with the 1JZ-GTE twin-turbo engine (2.5-litre, ~280 hp).

In Australia, the vast majority of A70 Supras are grey-imported MA70 turbo models. GA70 NA models are less common and less desirable. JZA70 models with the 1JZ-GTE are rare outside Japan and highly sought after. There were also 2.0-litre variants sold in Japan (GZ20 chassis code) that are almost never seen here.

Will the head gasket definitely fail on my 7M?

On the 7M-GTE turbo: yes, eventually. It's a matter of when, not if. Toyota designed the 7M head with only 10 head bolts, not enough clamping force for the pressures generated under boost. The factory composite head gasket degrades over thermal cycles and eventually blows. Some 7M-GTEs last 200,000 km before failure; others go at 80,000 km. There's no reliable way to predict when it will happen.

On the 7M-GE naturally aspirated: it's less certain. Without boost pressure, the gasket is under less stress. Many NA 7M engines run their entire lives without a head gasket failure. But the underlying design weakness is still there.

The fix is well established: ARP head studs (part number 203-4205) and a Cometic multi-layer steel head gasket. This upgrade provides dramatically more clamping force than the factory bolts and is considered a permanent fix. The community consensus is clear: do the ARP studs proactively on any 7M-GTE. Don't wait for the gasket to fail.

How much does a 2JZ swap cost?

Expect to spend $8,000-15,000 for a DIY 2JZ-GTE swap using a secondhand engine, doing the work yourself. That breaks down roughly as:

• Engine (2JZ-GTE, secondhand from Japanese importer): $3,000-6,000 depending on mileage and accessories included
• Gearbox (R154 or V160): $1,500-4,000 (R154 is cheaper)
• Engine mounts (aftermarket kit): $400-800
• Wiring harness (adapt or aftermarket): $500-1,500
• ECU (standalone like Haltech or Link, or adapted factory): $500-2,500
• Intercooler and piping: $500-1,500
• Radiator, hoses, cooling plumbing: $300-800
• Exhaust manifold, downpipe, exhaust: $500-2,000
• Driveshaft (custom or adapted): $300-600
• Miscellaneous (fluids, gaskets, mounts, bolts): $500-1,000
• Tuning: $500-1,500

A shop build doubles the total cost due to labour. The quality of the wiring and tune is what separates a reliable daily driver from an unreliable money pit. Don't cheap out on the wiring or the tune, they're the foundation of the entire build.

Is the W58 gearbox strong enough for a turbo build?

No. The W58 was designed for the naturally aspirated 7M-GE and is marginal even at stock turbo torque levels. It will survive behind a mildly tuned 7M-GTE for a while, but any serious power increase will kill it. The 2nd and 3rd gear synchros are the first to go, followed by the output shaft.

If you're building a turbo car, you need an R154 at minimum. The R154 handles up to approximately 500 hp (with a quality clutch). Beyond that, you're looking at a V160 Getrag 6-speed ($4,000-8,000 secondhand) or a CD009 swap from a Nissan 350Z/370Z (increasingly popular and cheaper than the V160).

The W58-to-R154 swap is one of the most well-documented modifications on the A70 platform. It requires a different bellhousing, clutch, hydraulic line, and potentially a different tailshaft. Budget $1,500-3,000 all-in for a DIY swap.

What turbo should I upgrade to?

That depends entirely on your power target and how you want the car to drive.

• Stock CT-26 (rebuild): 200-250 hp. Fine for a stock or mildly modified 7M-GTE. Spools quickly, responsive at low RPM.
• Garrett GTX3071R / BorgWarner EFR 6758: 300-450 hp. Good street turbo for a 2JZ. Quick spool, responsive, still has a top end. Popular choice for daily-driven cars.
• BorgWarner S362 / Garrett GTX3582R: 450-650 hp. The mid-range power turbo. Slightly slower spool than the smaller options but significantly more top-end power. The most popular choice for street/strip 2JZ builds.
• Garrett GTW3884R / BorgWarner S366: 600-800+ hp. Big turbo territory. Laggy at low RPM but enormous top-end power. For drag racing and track-focused builds.

For a 7M-GTE (stock engine), upgrading beyond the CT-26 is pointless, the engine itself becomes the limiting factor around 300 hp. The money is better spent on a 2JZ swap.

For a 2JZ-GTE, the BorgWarner S362 or Garrett GTX3582R is the sweet spot for a car that needs to be both streetable and fast. These turbos spool reasonably on a 3.0-litre engine and make genuinely scary power at the top end.

What injectors do I need?

Injector sizing depends on your power target and fuel pressure:

• Stock 7M-GTE (260 cc): Good for ~230 hp. Adequate for stock turbo at stock boost.
• 440 cc: Good for 300-350 hp. Common mild upgrade for a 7M-GTE with basic bolt-ons and a tune.
• 550 cc (RC Engineering): Good for 350-500 hp. The most popular injector for moderate 2JZ builds. RC Engineering 550s are the community standard at this level.
• 1,000 cc: Good for 500-750+ hp. Required for big-turbo 2JZ builds. Injector Dynamics ID1050X or Bosch EV14 are popular choices.
• 1,300-2,200 cc: For drag racing and extreme builds making 800+ hp.

Any injector swap requires a retune. Running mismatched injectors and tune is a guaranteed way to run lean under boost and destroy the engine. Get the tune done properly on a dyno with a wideband O2 sensor.

What clutch should I run behind the R154?

The R154 uses a pull-type clutch, which limits your options compared to push-type setups. Common choices for the R154:

• Stock replacement (Exedy or similar): Good for stock power. Smooth engagement, easy to live with in traffic. Budget $300-500.
• ACT Heavy Duty (street disc): Good for 300-400 hp. Slightly firmer pedal than stock but still streetable. Budget $600-900.
• RPS carbon twin-plate: Good for 400-600 hp. Light pedal for a multi-plate, holds serious torque. Popular choice for street/strip cars. Budget $1,200-2,000.
• XTD twin-plate: Budget alternative to RPS. Good for 350-500 hp. Heavier pedal feel. Budget $800-1,200.
• Exedy Hyper Single: Good for 400-500 hp. Strong single-plate option with a heavy pedal. Budget $800-1,400.

For a daily-driven car making under 400 hp, the ACT heavy-duty is the best balance of holding power and driveability. For a car that sees track or strip use regularly, the RPS carbon twin is the community favourite.

Are poly bushes a good upgrade for the suspension?

No, and this is a commonly misunderstood point. The A70 does not use rubber bushings in its suspension arms. It uses pressed spherical bearings, precision components that provide zero-deflection pivot points. This is a racing-derived design that gives the A70 its unusually precise handling.

When these spherical bearings wear out (they develop play after 100,000+ km), the correct replacement is new spherical bearings. Fitting polyurethane bushings in their place is a downgrade, you're replacing a zero-deflection bearing with a compliant bush that allows the suspension geometry to shift under load. The car will feel vague at turn-in and less predictable in transitions.

If a mechanic recommends poly bushes for your A70, they're likely unfamiliar with the car's suspension design. Source correct spherical bearing replacements from a specialty supplier.

The one area where poly bushes are appropriate is the subframe mounts, where the factory uses rubber mounts. Poly subframe mounts reduce movement and improve chassis response. This is a legitimate upgrade.

My 7M has low oil pressure at idle, how bad is it?

It depends on the numbers. Measure with a mechanical gauge, not the factory warning light (which only comes on at catastrophically low pressure).

• Above 15 psi hot idle: Normal for a 7M with some mileage. No action needed.
• 10-15 psi hot idle: Getting low but not immediately dangerous. Install an upgraded oil pressure relief valve spring ($30-50, 30-minute job). Switch to 15W-40 oil if you're running thinner. Monitor regularly.
• Below 10 psi hot idle: Concerning. The oil pump is significantly worn. Plan for an oil pump replacement ($400-800 including labour). Don't drive the car hard until this is addressed.
• Below 5 psi at hot idle or oil light flickering: Stop driving immediately. You're damaging bearings. The engine needs the oil pump replaced and potentially a bottom-end inspection for bearing damage.

An oil cooler relocation kit ($150-300) helps maintain oil temperature and viscosity in hot conditions, which indirectly supports oil pressure. This is a worthwhile upgrade for any 7M-GTE in Australian conditions.

Can I daily drive an A70 Supra?

Yes, but with caveats. A well-maintained A70 with a healthy engine (head gasket sorted, cooling system in good condition) is a reliable daily driver. The turbo engine provides comfortable highway cruising, the cabin is spacious for a sports car, and visibility is good by modern standards.

The challenges of daily driving:

• Fuel economy: 12-15 L/100 km for the turbo. That's expensive at current fuel prices.
• Parts availability: If something breaks, you may wait weeks for parts from Japan.
• Parking: Pop-up headlights extend the visual length, and the car is wider than it looks. Modern car parks are tight.
• Air conditioning: The factory A/C system often needs regassing or compressor replacement on 30+ year old cars. Budget $500-1,000 to sort.
• Ride quality: The sport suspension is firm. If you're coming from a modern car, the A70 will feel stiff.
• Insurance: Modified car insurance is more expensive and may have usage restrictions (e.g., annual kilometre limits).

A stock or mildly modified 7M-GTE on an R154 manual is the best daily driver configuration. Heavily modified 2JZ cars with aggressive cams, big turbos, and stiff suspension are miserable in traffic.

How do I check the targa roof for leaks?

The simplest test: park the car on a slight incline (nose up) and run a garden hose over the targa seal area for 5 minutes. Then check inside, look for drips around the A and B pillars, staining on the headliner, and moisture on the door sill carpets.

If it leaks:

1. Remove the targa panel and clean the seal channels thoroughly. Remove all debris, old sealant, and grime.
2. Inspect the rubber seals. If they're cracked, hardened, or compressed flat, replace them. Toyota still supplies replacement seals for the A70.
3. Check the targa bolts. If they're seized, don't force them, soak in penetrating oil for days. Seized bolts that are forced will strip the threads.
4. On reassembly, apply a thin layer of rubber seal conditioner (not silicone spray) to the seals. This keeps them supple and improves sealing.

What's the A70 worth as a project car versus a finished car?

The market has shifted dramatically. Five years ago, you could buy a running A70 turbo for $10,000-15,000. In 2026:

• A non-running project (7M-GTE, needs everything): $8,000-15,000
• A running driver (7M-GTE, sorted but cosmetically rough): $15,000-25,000
• A good stock turbo car: $25,000-40,000
• A well-built 2JZ swap: $35,000-60,000+

The economics of buying a project and building it to a high standard rarely work in your favour. A clean, well-sorted car for $35,000 is almost always better value than buying a $10,000 project and spending $30,000 on parts and labour, because you'll spend $30,000 on parts and labour and still have a car that's worth $35,000.

The exception is if you do all the work yourself and value the experience over the accounting. Building a car teaches you things that buying a finished car never will.

Are parts still available?

Mixed. Here's the breakdown:

• 7M engine internals (pistons, bearings, gaskets): Still available from Toyota and aftermarket. No immediate supply concerns.
• ARP head studs and Cometic gaskets: Readily available from performance parts suppliers. These are current-production items.
• Turbo (CT-26): Rebuild kits are available. Replacement CT-26 turbos are getting scarce, most people upgrade to a larger aftermarket turbo anyway.
• R154 gearbox parts: Available but getting more expensive as demand from the drift community pushes prices up.
• Body panels: Very scarce new. Japanese wreckers are the primary source. Bonnets, guards, and bumpers are available but expensive to ship.
• Interior trim: Scarce. Dashboards, door cards, and seat trim are hard to find in good condition. Japanese auction sites are the best bet.
• Suspension components: Aftermarket coilovers are readily available. OEM suspension arms and spherical bearings are available through specialty suppliers.
• Electrical: Wiring harnesses are available new from aftermarket specialists (Wiring Specialties). Sensors and switches are still available from Toyota for most items.
• 2JZ swap parts: Excellent availability. The 2JZ aftermarket is enormous and well-supplied.

The general rule: anything that's shared with the A80 or other Toyota models is fine. Anything unique to the A70 (body panels, interior trim, A70-specific mounts) is getting harder to source.