Tuning the Volkswagen D24

"Comprehensive guide to tuning the Volkswagen D24 engine!"

We are frequently getting emails asking how to improve the D24 from people wanting to know what are the best tips for D24 power upgrades. So let us look into Volkswagen D24 tuning mods and outline the best upgrades on this great engine and point out some potential pitfalls along the way.

The Volkswagen D24 offer good returns when tuned and with the ultimate tuning parts like remapping, turbo improvements and camshafts you will definitely maximise your driving pleasure.

Let us review and look at D24 tuning and report on the best mods that work.

When talking about the best parts for your D24 engine, we are going to concentrate on the upgrades that give the biggest return for your cash.

Altering your D24 camshaft will make a dramatic difference to the engine bhp. Choosing a higher performance camshaft profile raises the bhp accordingly.

NB: Fast road cams usually bump the bhp throughout the rev band, you might lose a little low end power but high end rpm power will improve.

Race cams, bump the high end rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

On a car driven daily you need to optimize your power band to your cars usage.

You'll never find a D24 Race camshaft is a pleasure to live with when driving around busy urban areas.

Different D24 engines respond better to more or less aggressive cam durations than others.

The map and fuel pump and injectors also have an effect on the torque gains you'll achieve.

Extending exhaust or intake durations can alter the torque band and on most engines the exhaust and intake durations do not need to match, although most cams and tuners use matched pairs there are some advantages to extending the intake or exhaust durations.

D24 Tuning Stages

Stage 1 D24 modifications: Drilled & smoothed airbox, Sports exhaust manifold, Intake headers, Panel air filters, Fast road camshaft, Remaps/piggy back ECU.

Stage 2 D24 modifications: Ported and polished head, Sports catalyst & performance exhaust, high flow fuel injectors, fuel pump upgrades, induction kit, Fast road cam.

Stage 3 D24 modifications: Twin charging conversions, Competition cam, Engine balancing & blueprinting, Internal engine upgrades (head flowing porting/bigger valves), Adding or Upgrading forced induction (turbo/supercharger), Crank and Piston upgrades to alter compression.

The D24 units are great to work on and thanks to their popularity there is a growing number of mods and tuning parts about.

ECU flashing should help to release the full potential of all the modifications you've done to your D24.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but figures achieved usually vary depending on the modifications you've applied and the condition of your engine.

Pushing air into each cylinder is the whole point to any performance tuning task.

Headers transmit the air from the air cleaner and allow it to be sucked into the engine and mixed with fuel.

Shape and flow rate of the Headers can make a big difference to to fuel mixing and power on the D24.

Commonly we find the plenum chambers are needing motorsport parts, although some manufacturers provide reasonably good plenum chambers.

Big valve conversions on the D24, doing a bit of port work and head flowing will also improve torque, & importantly will make space for a better torque increase on other mods.

Turbo upgrades for the D24

NASP engines need quite a lot of work when you add a turbo, so we have a separate guide to help you take into account the pros and cons of going this route on your D24

The more air you can get into an engine, the more fuel it can burn and uprating the induction with a turbocharger upgrade makes major power gains.

If an engine is turbo charged parts are more reliable and most turbocharged engines will have more solid components.

However every engines have limits

See where you'll find these restrictions and upgrade to better pistons and crank to utilize the power.

We've seen people spending a loads of money on turbo charger upgrades on the D24 only to suffer the humiliation of seeing the engine literally blow up just after it's first rolling road session.

Large capacity turbo chargers will usually suffer low end lag, and low capacity turbo chargers spool up really quickly but don't have the peak end bhp gains.

Thankfully the world of turbos is always increasing and we are seeing variable vane turbos, permitting the vane angle is altered according to speed to lower lag and increase top end bhp.

Twin scroll turbos divert the exhaust gases into a couple of channels and direct these at differently designed vanes in the turbo. They also improve the scavenging effect of the engine.

You'll commonly see there is a restriction in the air flow sensor MAP/MAF/AFM on the D24 when loads more air is being sucked into the engine.

We note 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting performance at a much lower level.

Adding a supercharger or additional turbo will make large performance gains, although more complex to install. We have this article covering twinchargers if you want to read more.

Uprating D24 fuel injectors

When you raise the bhp and torque you will need to look at to the fuel delivery.

More bhp and torque needs more fuel. We strongly recommend you to be generous with your flow rate on the injectors.

The accepted safe increase is to add another 20% when buying an injector, this accounts for injector deterioration and allows a bit of spare capacity should the engine need more fuel.

We think this one is common sense, but you'll need to match your fuel injector to the type of fuel your car uses as well.

Best D24 performance exhausts

You may need to uprate your exhaust if the current exhaust is creating a restriction.

On most factory exhausts you'll find the flow rate is good even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust.

Do not go with the biggest exhaust you can get this will reduce the exhaust flow rate - the best for power gains are usually between 1.5 to 2.5 inches. It is the shape and material more than the bore size.

Typically exhaust restrictions are traced to the filters installed, so adding a better flowing high performance alternative will help avoid this restriction.

Problems and issues to look out for on the D24

The D24 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the D24, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your D24 engine please join us in our friendly forum where you can discuss tuning options in more detail with our D24 owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

We need your help to complete and improve this page, so do give us your feedback in the comments box below.

We really like hearing from our readers, and hearing about which parts were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our D24 guides and tips are kept up to date.

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