Tuning the Ford Duratec 35

"Comprehensive guide to tuning the Ford Duratec 35 engine!"

We are regularly getting messages asking about the premier Duratec 35 mods that work. So let us look into Ford Duratec 35 parts and outline the best modifications on this great engine and point out some problems along the way.

The Ford Duratec 35 are good project engines and with carefully chosen uprated parts like remaps, turbo kits and camshafts you will certainly increase your driving enjoyment.

This pages aim is review and look at Duratec 35 tuning and highlight the best modifications. The Duratec 3.5 is also internally known as the Ford Cyclone V6 Engine and was designed by Ford and Porsche in collaboration.

Just because particular parts are popular with Duratec 35 owners it doesn't mean it is good, we shall concentrate) on the top parts that will give your Duratec 35 the best power gain for you money.

The cam profile plays a big part in the engines power output so cam upgrades make quite a large difference. The intake and exhaust durations will alter depending on the chosen cam profile, so large bhp gains are on offer for cam upgrades.

NB: Fast road cams normally increase the power over the rev range, you could sacrifice a little low down torque but your high end rpm power will improve.

Competition cams, increase 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 one should, ideally, try to optimize your torque band to your driving style.

I'd never have ever thought a Duratec 35 Motorsport cam is a pleasure to live with when in heavy traffic.

Some Duratec 35 engines respond better to mild cam durations than others.

The engine timing and injectors and fuel pump also will make differences on the torque gains you'll get.

Altering valve 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.

Duratec 3.5 Best Tuning Mods & Upgrades

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Tuning Stages

Stage 1 Duratec 35 modifications: Intake headers, Fast road camshaft, Panel air filters, Remaps/piggy back ECU, Sports exhaust manifold, Drilled & smoothed airbox.

Stage 2 Duratec 35 modifications: fuel pump upgrades, induction kit, high flow fuel injectors, Fast road cam, Ported and polished head, Sports catalyst & performance exhaust.

Stage 3 Duratec 35 modifications: Engine balancing & blueprinting, Crank and Piston upgrades to alter compression, Internal engine upgrades (head flowing porting/bigger valves), Competition cam, Adding or Upgrading forced induction (turbo/supercharger), Twin charging conversions.

A remap will help fully realize the full potential of all the tuning mods you've done to your Duratec 35.

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 will rely on the tuning mods you've fitted and the condition of your engine.

Pushing air and fuel into your Duratec 35 is the aim to any engine tuning task.

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

The bore size, shape and flow characteristics of the Intake headers can make a noticeable difference to to fuel atomisation and engine efficiency on the Duratec 35.

We often see intake manifold are ripe for aftermarket tuning parts, although a few makers provide well optimised intake manifold.

Larger Duratec 35 valves, getting 3 or 5 angle valve jobs and porting and head flowing will also improve bhp and torque, the fantastic side effect is it will afford you a greater bhp and torque increase on other modifications.

Turbo upgrades for the Duratec 3.5

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 Duratec 35

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

If an engine is fitted with a turbocharger tuning mods are simpler to install and you'll see that turbo engines are built with uprated components.

However you'll find engines will need better parts at higher power limits

We recommend you find these limitations and install forged components to cope with the power.

It's not unheard of people spending a fortune on turbo charger upgrades on the Duratec 35 only to suffer the indignity of watching the motor literally blow up on it's first outing after it's used in anger.

Big capacity turbos tend to experience no power at low rpm, and smaller turbos spool up quickly but don't have the top end torque gains.

In the last 10 years the world of turbos is always improving 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 2 channels and flow these at differently designed vanes in the turbo charger. They also improve the scavenging effect of the engine.

You'll commonly see there's a limitation in the air flow sensor (AFM/MAF/MAP) on the Duratec 35 when considerably 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 bhp and torque at a much lower level.

Adding a supercharger or additional turbo will make large bhp and torque gains, although more difficult to get working. We have this article on twincharging if you want to read more.

Uprating Duratec 3.5 fuel injectors

Don't miss you'll need to increase the fuel system when you are increasing the bhp - it makes the car more thirsty. Don't forget to be generous with your injector capacity.

The accepted safe increase is to add 20% when fitting an injector, helps cope with injector deterioration and allows you some 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 Duratec 3.5 performance exhausts

You may need to upgrade your exhaust if the current exhaust is actually causing a restriction in flow.

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.

Sports exhausts generally help improve air flow from the engine but avoid an exhaust that is too large or you could will reduce the flow rate. Stick to 1.5 to 2.5 inches as a rule of thumb.

Common exhaust restrictions can be located the emissions filters installed, so adding a faster flowing high performance alternative will help avoid this restriction.

Problems and issues to look out for on the Duratec 3.5

The Duratec 35 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the Duratec 35, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your Duratec 35 engine please join us in our friendly forum where you can discuss tuning options in more detail with our Duratec 35 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 upgrades were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our Duratec 35 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 Ford. 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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