Tuning the Volvo D5204

"Comprehensive guide to tuning the Volvo D5204 engine!"

We often are getting emails requesting info on the best tips for D5204 mods that work. So let us look into Volvo D5204 modifications and outline the best mods that work on this great engine and point out some potential pitfalls along the way.

In this article we review D5204 tuning and point out the ultimate modifications. Volvo D5204 offer good returns when tuned and with carefully picked uprated tuning mods like a remap, turbo upgrades and camshafts you will greatly improve your driving fun.

When talking about the top parts for your D5204 engine, we are going to concentrate on the mods that give the best power gain for you money.

Significant gains on the D5204 can be made from camshaft upgrades. Altering the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the bhp and power output.

NB: Fast road cams tend to bump the torque over the rev range, you may lose a little bottom end power but your higher rpm power will improve.

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

A Motorsport camshaft is not great on the daily commute.

You should ideally match your torque band to your typical driving style so for a car used daily stick with a mild fast road D5204 camshaft

Each engine responds better to extreme camshaft durations so view each engine as unique.

The engine timing and injectors and fuel pump also will say much on the power gains you'll get.

Extending exhaust or intake durations can alter the power 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.

D5204 Best Tuning Mods & Upgrades

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Tuning Stages

Stage 1 D5204 modifications: Sports exhaust manifold, Drilled & smoothed airbox, Fast road camshaft, Intake headers, Remaps/piggy back ECU, Panel air filters.

Stage 2 D5204 modifications: induction kit, fuel pump upgrades, Fast road cam, Ported and polished head, Sports catalyst & performance exhaust, high flow fuel injectors.

Stage 3 D5204 modifications: Internal engine upgrades (head flowing porting/bigger valves), Competition cam, Crank and Piston upgrades to alter compression, Twin charging conversions, Engine balancing & blueprinting, Adding or Upgrading forced induction (turbo/supercharger).

ECU flashing should help to release the full potential of all the upgrades you've done to your D5204.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but your mileage may rely on the upgrades you've carried out and the condition of your engine.

Forcing air and fuel into each cylinder is the main goal to any engine upgrade task.

Intake manifold flow the air during the suck phase from the filter and allow it to be fed into the engine cylinders with fuel for the squish phase.

Shape and flow rate of the Intake can make a noticeable effect on to fuel atomisation and engine efficiency on the D5204.

It's not uncommon that intake are ripe for a performance upgrade, although some manufacturers provide reasonably good intake.

Fitting big valve kits, doing some port work and head flowing will also improve performance, and importantly will make space for increasing the performance increase on other upgrades.

Turbo upgrades for the D5204

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 D5204

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

When a car is turbo charged parts are simpler to install and turbocharged engines are made using stronger components.

There are practical limits for every engine, with some being over specified and some only able to handle stock power

See where you'll find these restrictions and fit stronger pistons, crank and engine components to handle the power.

We've seen guys spending a loads of money on turbo charger upgrades on the D5204 only to suffer the indignity of watching the whole thing throw a rod just after it's been finished.

Larger capacity turbos often suffer low end lag, and low capacity turbos spool up much more quickly but don't have the peak rpm bhp gains.

We are pleased that the market of turbochargers is always improving and we now see variable vane turbochargers, permitting the vane angle is altered according to speed to lower lag and increase top end torque.

Twin scroll turbochargers divert the exhaust gases into two channels and feed these at differently designed vanes in the turbo. They also boost the scavenging effect of the engine.

You'll commonly see there's a limitation in the air flow sensor (AFM/MAF/MAP) on the D5204 when considerably more air is being pulled into the engine.

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

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

Uprating D5204 fuel injectors

When you improve the power you will need to pay attention to to the fuel delivery.

More power needs more fuel. We would recommend you to over specify your flow rate on the injectors.

The accepted safe increase is to add 20% when specifying an injector, which takes into account injector deterioration and affords a bit of spare capacity should the engine require 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 D5204 performance exhausts

You should look to improve your exhaust if the existing exhaust is actually causing a flow problem.

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

Don't go with the widest exhaust you can get this will slow the exhaust 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.

Common exhaust restrictions typically happen through the catalyst and or DPF filters which manufacturers fit, especially as they start to get worn and carbon builds up, so adding a higher flowing performance alternative will help avoid this restriction.

D5204 Engine bhp specs and history

The D5204 was  a very well built diesel engine and copes well with modifications, it was not available in North America where diesels were dropped but elsewhere it has proved to be a fantastic engine.

• 2.0D I4 148 hp D5204T5
• 2.0D I5 175 hp D5204T

Problems and issues to look out for on the D5204

The D5204 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the D5204, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your D5204 engine please join us in our friendly forum where you can discuss tuning options in more detail with our D5204 owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

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We really like hearing from our readers, and hearing about which modifications were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our D5204 guides and tips are kept up to date.

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This article is flagged for an update, so please pass on specific tips below that I can include. All articles, and content was written by me, Waynne Smith TorqueCars founder. Some outlines are just too general so I appreciate your feedback and suggestions. This entry was filed under Volvo. You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

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