Tuning and Modifying the Jaguar AJ-V8 Engine for Enhanced Performance

The Jaguar AJ-V8 engine is a marvel of British engineering—a V8 with silky smooth delivery, excellent reliability, and V8 rumble that can turn any luxury sedan or sports car into a beast. But for those who want something more than the out-of-the-box performance from their AJ-V8, tuning and modifying the engine is an exciting route to unleashing its maximum potential. Tuning and Modifying the Jaguar AJ-V8 Engine for Enhanced Performance

Whether you’re restoring a classic Jaguar, swapping engines in a custom build, or simply upgrading for power and performance, we’ve got tuned and modified Jaguar AJ-V8 engines for sale that will meet and exceed your expectations.

In this article, we cover all you need to know about AJ-V8 engine modification and tuning, from factory specifications to after-market performance enhancements—and most critically, how you can get a performance-tuned AJ-V8 engine from us.

What is the Jaguar AJ-V8 Engine?

The 1996 Jaguar AJ-V8 was a departure from Jaguar heritage as it left behind its traditional inline-six and V12 engines. This modular-configured V8 engine has propelled a gargantuan range of Jaguar models, ranging from luxury XJ models to performance XKR to outrageously powerful XF-R.

The AJ-V8 went through some variations throughout the decades, in naturally aspirated and supercharged form, displacements ranging from 3.2L to 5.0L.

Key Specifications (Base AJ-V8 Engines)

Spec	AJ26 / AJ28	AJ33 / AJ34	AJ-V8 Gen III (5.0L)
Displacement	4.0L / 4.2L	4.2L	5.0L
Configuration	90° V8 DOHC	90° V8 DOHC	90° V8 DOHC
Valvetrain	32-valve	32-valve	32-valve with VVT
Compression Ratio	10.75:1	11.0:1	11.5:1
Power Output	290-400 hp	300-420 hp	385-550+ hp
Torque	290-413 lb-ft	310-430 lb-ft	380-502 lb-ft
Fuel System	Sequential EFI	Direct Injection	Direct Injection
Induction	NA / Supercharged	NA / Supercharged	NA / Supercharged

They’re great as it is—but we’re great at pushing them higher.

Why Tweak the Jaguar AJ-V8?

While the AJ-V8 is good as it is, tweaking and modifying it will push it so much further:

Horsepower & Torque
Throttle Response
Engine Longevity
Fuel Efficiency (with good tuning)
Track and Street Performance

Our shop sells modified Jaguar AJ-V8 engines pre-tuned for maximum performance. Whether street-friendly daily drivers or track beasts, we have an AJ-V8 build to meet your objectives.

Tuning & Modification Ideas

We will list the most wanted and most efficient performance modifications for the AJ-V8 engine.

1. ECU Tuning / Remapping (Tuning and Modifying the Jaguar AJ-V8 Engine for Enhanced Performance)

The solution to unleashing power is ECU remapping. Factory settings bias emissions and economy. Our performance tunes are tweaked to:

Alter fuel-air ratio
Alter ignition timing
Alter throttle mapping
Kill rev limiters

Result: Power increases of 40-80 hp depending on the model and supporting mods.

Our entire range of engines have custom ECUs tuned to ride in conjunction with performance upgrades and deliver safe power to the wheels.

2. Forced Induction: Superchargers & Turbochargers

The AJ-V8 is already available in supercharged variants, but there’s room to grow. Adding or upgrading forced induction can provide:

30–60% more horsepower
Massive low-end torque
Better high-RPM powerband

We offer pre-supercharged AJ-V8 engines for sale, built with forged internals and ready for high boost.

3. Upgraded Internals

Pushing power beyond 500 hp? You’ll need stronger internals:

Forged Pistons
Forged Connecting Rods
Steel Crankshafts
High-performance Head Studs

These upgrades make your engine handle more stress without compromising reliability. All our high-output packages feature upgraded internals as standard.

4. Intake & Exhaust Upgrades

More breathing = more power. Significant upgrades are:

Cold Air Intakes
Ported and Polished Heads
High-Flow Exhaust Manifolds
Performance Cat-Back Exhausts

These not only deliver power but also give your Jaguar a deep, mean sound.

5. Camshaft and Valve Timing Upgrades

For NA engine builds, camshaft modifications and VVT tuning can provide serious top-end power.

More aggressive cam profiles
Better valve timing
Enhanced High-RPM efficiency

These modifications, when combined with ECU tuning, can unleash +50 hp from NA engines.

Performance Builds We Sell

We don’t talk about performance—we do. Our selection of custom AJ-V8 engines for sale includes:

Stage 1: Performance Street Build (350–420 hp)

Enhanced intake & exhaust
ECU tune
Valve spring reinforcement

Perfect for street driving with attitude
Plug-and-play on most Jaguar platforms

Optimal for: XJ, XK8, XF street build

Stage 2: Supercharged Track Build (500–600+ hp)

Factory or aftermarket supercharger
Forged pistons & rods
High-performance fuel injectors & fuel pump
Custom ECU tune
Optional meth injection

Best for: Track-day toys, drag builds, performance swaps

Stage 3: Full Custom Race Build (600–750+ hp)

Twin-turbo or high-boost supercharged setup
Full internal upgrade (forged internals, billet components)
High-performance cooling system
Dry sump system (optional)
Data-logged tuning for dyno precision

Recommended For: Restomods, custom cars, drift cars, drag racing

Engine Swaps & Compatibility

Our AJ-V8 engine is extremely versatile and has successfully been swapped into:

Classic Jaguars (E-Type, XJ6)
Kit cars (Factory Five, Cobra replicas)
Custom hot rods
Land Rover conversions
Other European & JDM projects

We have mounting kits, wiring harnesses, and ECU solutions to facilitate smooth swaps. Call us for custom installs!

Why Buy From Us?

We’re not engine builders, we’re performance addicts. Each and every AJ-V8 engine that we sell undergoes:

Multi-point inspection
Compression & leak-down test
Entire tear-down & cleaning
Machining & blueprinting
Rotating assembly balancing
Dyno tuning (optional)

We use OEM or better-quality components, and our engines come backed up with warranty choices for extra peace of mind.

What’s in Our Engine Packages?

Each of the packages we have available can be customized to your order, but will generally include:

Assembled long block
Intake manifold
Throttle body
Fuel injectors
Oil pan (wet or dry sump)
Plug-and-play tuned ECU
Optional engine wiring harness
Supercharger or turbo (if required)

Tell us your project specs, and we’ll build to that.

Installation Support & Guidance

Installation in question? We’ve got you covered:

Detailed install instructions
Wiring diagrams
Remote assistance
ECU flashing & reprogramming

We work with shops throughout North America and Europe to perform the installs there if needed.

Testimonials

“I replaced a Stage 2 AJ-V8 in my XJ and night and day is the difference. Power is smooth, aggressive, and consistent. Highly recommend!”
– James M., California

“Bought a complete assembled 5.0L supercharged AJ-V8 for my custom kit car. Fit perfectly, runs wonderfully, and sounds crazy.”
– Markus R., Germany

Prices & Availability

Pricing varies with configuration:

Stage 1 Builds: $4,995 and up
Stage 2 Builds: $7,995 and up
Stage 3 Race Builds: Quote to Order

All engines quote to order with a nominal 2–4 week lead time.

Need financing or freight shipping? We’ve got you covered—worldwide.

Ordering

Buying your own personal AJ-V8 engine is easy:

Browse our available builds or ask for a custom quote.
Choose your degree of performance and options.
We test and build your engine.
We ship to you.
You install or use one of our certified affiliates.

Click [HERE] to get started or call us directly for a consult.

FAQs About the Jaguar AJ-V8

Q: Is the AJ-V8 reliable once modified?
A: Yes. With careful tuning and strengthened internals, the AJ-V8 is bulletproof up to 700+ hp.

Q: Will your engines fit my non-Jaguar project vehicle?
A: Absolutely! We can provide plug-and-play ECUs and harnesses for specialty swaps.

Q: How much fuel do I need?
A: 91+ octane on natural aspirated and 93+ or E85 on forced induction.

Q: Warranty?
A: Yes. There is a limited warranty on build application and use of all engines.

Final Thoughts: Why Choose the AJ-V8?

The Jaguar AJ-V8 is a unique engine with personality, performance, and tuning potential to boot. It’s a lighter weight V8 than others, revs nicely, and provides unique European muscle. In need of restoration, swap, or race build—our tuned and modified AJ-V8 is the one you’re looking for.

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