Unlock hidden performance in Australia’s classic workhorse engine
The Chrysler Valiant Slant 6 is a legendary engine known for its torque, durability, and reliability, powering Valiants from the 1960s through the 1980s. While the engine was never designed for high performance, enthusiasts have found that with careful modifications, turbocharging the Slant 6 can provide a significant boost in power and responsiveness.
If you’re considering a turbo Slant 6, it’s important to understand the pros, cons, and what’s involved in the build.
What Turbocharging a Slant 6 Involves
Turbocharging a Slant 6 is more than just bolting on a turbo. Key components include:
- Turbocharger unit – often a small-to-medium T3 or T4 style turbo for the Slant 6’s displacement
- Exhaust manifold – custom tubular headers to feed the turbo efficiently
- Intercooler – optional but recommended for keeping intake air temperatures lower
- Fuel system upgrades – larger carburettor or EFI conversion to handle extra fuel needs
- Ignition adjustments – optimized timing for boost
- Engine internals – stock Slant 6 is robust, but high boost requires forged pistons, stronger rods, and upgraded gaskets
Why it works: Turbocharging forces more air into the engine, allowing it to burn more fuel and create substantially more torque and horsepower, particularly in the mid-range where the Slant 6 already excels.
Pros of Turbocharging a Slant 6
- Big torque gains – the Slant 6’s naturally torquey design makes it a perfect candidate for boost
- Improved throttle response – especially for heavy cars like the Valiant sedan or wagon
- Relatively compact upgrade – the Slant 6’s simplicity allows turbo installation without major engine swaps
- Streetable performance – can be tuned for driveability rather than full-blown race setups
Cons of Turbocharging a Slant 6
- Limited factory internals – the Slant 6 wasn’t designed for extreme boost; too much can lead to failure
- Complexity and tuning – proper boost control, carburettor or EFI tuning, and ignition timing are critical
- Increased maintenance – higher stress on engine and transmission
- Heat management – turbo generates extra heat requiring upgraded cooling and oil systems
- Fuel consumption – more air and fuel equals higher running costs
Ballpark Cost of a Turbo Slant 6 Build
| Component/Upgrade | Estimated Cost (AUD) |
|---|---|
| Turbocharger & wastegate | $2,000 – $3,500 |
| Custom exhaust manifold & piping | $1,000 – $1,800 |
| Intercooler & plumbing | $700 – $1,500 |
| Fuel system upgrades | $500 – $1,000 |
| Engine tuning & dyno | $800 – $1,500 |
| Optional internal upgrades | $1,500 – $3,000 |
Total: $5 500 – $12 000+, depending on boost level and reliability requirements
Tip: For a street-friendly build, modest boost using mostly stock internals is achievable and much more affordable. High-boost setups require forged internals and careful tuning.
Key Considerations
Before turbocharging your Slant 6, consider:
- Do you want daily drivability or extreme performance?
- Are you ready to upgrade cooling, fuel, and ignition systems to handle the extra stress?
- Do you have access to expert tuning to ensure the engine is safe under boost?
A turbo Slant 6 is rewarding but requires planning, precision, and patience.
Final Thoughts
The Chrysler Valiant Slant 6 is a reliable and torquey engine, but turbocharging can transform it into a seriously fun performer. With the right combination of turbo, headers, fuel system, and tuning, you can unlock hidden power while retaining the engine’s classic character.
Whether you’re looking for a streetable cruiser or a weekend showpiece, a turbo Slant 6 offers exhilarating performance while keeping the nostalgia and charm of a classic Valiant.