Tuning the Volvo D20

"Comprehensive guide to performance tuning the Volvo D20 engine!"

We often are seeing threads requesting information on the best D20 mods that work. So let us look into Volvo D20 tuning mods and outline the best modifications on this great engine and point out some potential pitfalls along the way.

The Volvo D20 are popular engines and with the ultimate uprated mods like remaps, turbo improvements and camshafts you will certainly increase your driving opportunities.

Let us review and look at D20 tuning and show the optimum mods that work.

The greatest D20 parts on an engine are as we have found the ones that give the biggest return for your cash.

We won't be swayed by popular D20 parts, they need to be cost effective.

Significant gains on the D20 can be made from cam upgrades. Altering the cam profile alters the intake and exhaust durations on the engine and can dramatically change the power band and power output.

NB: Fast road cams tend to bump the torque throughout the rpm band, you may lose a little bottom end torque but your high end rpm power will improve.

Competition 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.

A Motorsport and race camshaft is not great driving in heavy traffic.

You should ideally optimize your power band to your preferences so for a car used daily stick with a shorter duration D20 camshaft

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

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

A longer valve duration can alter the bhp 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.

D20 Tuning Stages

Stage 1 D20 modifications: Remaps/piggy back ECU, Sports exhaust manifold, Panel air filters, Intake headers, Fast road camshaft, Drilled & smoothed airbox.

Stage 2 D20 modifications: fuel pump upgrades, high flow fuel injectors, Fast road cam, induction kit, Sports catalyst & performance exhaust, Ported and polished head.

Stage 3 D20 modifications: Internal engine upgrades (head flowing porting/bigger valves), Engine balancing & blueprinting, Crank and Piston upgrades to alter compression, Twin charging conversions, Adding or Upgrading forced induction (turbo/supercharger), Competition cam.

ECU mapping will help unlock the full potential of all the modifications you've done to your D20.

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

It is the aim to any engine performance tuning project to feed more air and fuel into your D20

Headers transmit the air from the air filter and allow it to be sucked into the engine cylinders with fuel for the squish phase.

The bore size, shape and flow rate of the Intake can make a noticeable change to fuel atomisation on the D20.

Commonly we find the intake manifold are in dire need of aftermarket parts, although a few OEM provide well optimised intake manifold.

Adding a D20 larger valve kit, doing a bit of port matching and head flowing will also increase bhp, and importantly will make space for a greater bhp increase on other tuning mods.

Turbo upgrades for the D20

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 D20

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

When your motor is turbocharged, tuning mods are going to net you a larger power gain and we find turbo engines use uprated components.

However engines will need better parts at higher power limits

Research these limitations and fit better quality components to survive the power.

It's not unheard of tuners spending a lots of money on turbocharger upgrades on the D20 only to suffer the humiliation of seeing the whole thing literally blow up on it's first outing after it's been finished.

Big upgraded turbo units often suffer a bottom end lag, and low capacity turbo units spool up really quickly but do not have the high rpm power band gains.

Over the last 20 years the range of turbos is always evolving and we commonly find variable vane turbos, where the vane angle is altered according to speed to lower lag and increase top end bhp and torque.

Twin scroll turbos divert the exhaust flow into a couple of channels and direct these at differently angled vanes in the turbo charger. They also increase the scavenging effect of the engine.

It is common that there's a restriction in the air flow sensor AFM/MAP on the D20 when loads more air is being pulled into the engine.

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

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

Uprating D20 fuel injectors

You will need to ensure that the engine is not starved of fuel so will have to look at the fuelling when you start extending past 20% of a power increase.It is important to be generous with your injector capacity.

As a rule of thumb add 20% to the flow rate when fitting an injector, this takes into account injector deterioration and allows you some 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 D20 performance exhausts

You only need to to upgrade your exhaust if the current exhaust is actually causing a flow problem.

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.

Sports exhausts generally help improve air flow from the engine but do not go too wide or you could will reduce the flow rate. Stick to 1.5 to 2.5 inches as a rule of thumb.

Common exhaust restrictions are in the catalyst installed, so adding a faster flowing race alternative will help avoid this restriction.

Problems and issues to look out for on the D20

The D20 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the D20, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your D20 engine please join us in our friendly forum where you can discuss tuning options in more detail with our D20 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 tuning mods were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our D20 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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