Ford Duratec 35 Tuning

"All you need to know about tuning the Ford Duratec 35 engine!"

As many of our forum members have asked about the Duratec 35 and tips on how to modify one, so we've put together this guide to cover the primary areas which make for improvement and tuning success on this great car.

Now we will review Duratec 35 tuning and outline the optimum mods that work. Ford Duratec 35 really good project engines and with the best performance mods like ECU maps, turbo kits and camshafts you will dramatically maximise your driving enjoyment.

Due to a combined effort by Ford and Porsche, the V6 Duratec engine was initially launched. The Duratec came into existence at this time. The roster includes a wide range of tough, flexible 4-, 5-, and 6-cylinder engines with inline and V layouts. The original block design proven to be adaptable and robust in a number of combinations and tuning levels.

See our video which provides a complete introduction to Ford Tuning, it contains some tips on performance and handling modifications.

History of the Duratec 35 Engine

  • Duratec 35 Ford Cyclone V6 Engine 3.5 L  DOHC V6 2006–present

This all-new Duratec 35 3.5L DOHC V-6, became a Ward’s 10 Best Engines winner in its first year and has won many fans over the years.

It was released in the following Ford models

With a rebore to 3.7 liters, this engine virtually becomes the Duratec 37 which has made some impressive power figures.

Fore example Radical developed the RXC V6 engine is based on the Duratec 37 Cyclone, while Ginetta's 3.7Ti-VCT produces 310 horsepower and this goes some way to show what the Duratec 35 Ford Cyclone V6 Engine 3.7 L  DOHC V6 is capable of in the right hands with the right performance mods and upgrades. The pistons stroke in the Duratec 37 is the same as that of the Duratec 35 so it retains many of the characteristics of its smaller capacity brother offering more power output.

Tuning the Ford Duratec 35 and best Duratec 35 performance parts.

Best Duratec 35 tuning mods

Just because particular upgrades are are common on Duratec 35 it doesn't mean its worth having, instead we'll focus on the greatest upgrades that will give your Duratec 35 the best value for money to power increase.

Please watch our video which covers the 5 principles of tuning your Duratec 35. Be sure to subscribe and support our new channel.

Best mods for your Duratec 35

  1. Remaps - A remap provides the most power in terms of cost, aftermarket ECU upgrades, and inline Tuning boxes are all alternatives.
  2. Fast road Camshafts are generally the biggest mechanical mod upgrade, but they must be fitted by someone who knows what they are doing and they are not always easy to source but you might find a local firm to regrind a stock camshaft.
  3. Intake and Performance Exhausts - Note that on their own these mods will NOT ADD POWER in most cases, but they can help enhance power after other mods by removing the restriction.
  4. Forced induction upgrades - A New Turbo is the most efficient approach to increase air supply, allowing you to burn more fuel and make more power. It is one of the most costly upgrades it offers big gains.
  5. Internal engine mods - crank, pistons, conrods & compression ratio including balancing and blueprinting

Duratec 35 Tuning Stages

Typical stage 1 mods often include: Sports exhaust manifold, Panel air filters, Remaps/piggy back ECU, Intake manifolds, Drilled & smoothed airbox, Fast road camshaft.

Typical stage 2 mods often include: fuel pump upgrades, high flow fuel injectors, Fast road cam, Ported and polished head, induction kit, Sports catalyst & performance exhaust.

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

Camshaft Upgrades

Sporty camshaft profiles come into their own at upper RPM range power so are more suited to petrol engines, than diesel ones. You will usually get a top end power increases through performance camshafts on most engines. So altering your Duratec 35 cam will make a difference to the engine engines power. Choosing a higher performance cam profile raises the power curve accordingly.

Fast road cams usually push up the bhp and torque through the rpm range, you may sacrifice a little low end power but high end rpm power will be higher.

Motorsport and race cams, push up the high end rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

In a daily driver it makes a lot of sense to match your power band to your preferences.

I'd be surprised if you have found a Duratec 35 Motorsport camshaft is a pleasure to live with when driving in heavy traffic.Because your low end power will be very lumpy. Competition cams are designed to lift the maximum power at the top part of your RPM range, a place that most daily commutes will not usually permit!

Different Duratec 35 engines respond differently depending on how well made they are, when camshafts are fitted depending on the camshaft being more extreme camshaft durations and cam profile as unique due to manufacturing tolerances and quality variations so check your engine on a rolling road.

The ecu map and fuel delivery and fuel pump and injectors also will make differences on the power gains you'll hit.

A longer valve duration can adjust the power curve, and on most engines there are some advantages to extending the intake or exhaust durations and valve lift.

Review your options and then find your tuning parts and set yourself a power target to avoid costly mistakes.

ECU Mapping Improvements

ECU mapping should help to unlock the full potential of all the mods you've fitted to your Duratec 35.

(Sometimes flashing the ECU is not an option, so an aftermarket ECU is the route to take, and most of these exceed the specs and performance of your factory ECU's but make sure it has knock protection and that you get it installed right.) It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NA (naturally aspirated) engines, but the end result may vary depending on the mods you've applied and the condition of your engine.

Air Flow improvements (intake mods)

The objective of any performance tuning work on the Duratec 35 engine is to increase airflow.

The intake manifold transports the air from the intake filter into the engine cylinders, where it is mixed with fuel for the squish phase of the combustion process.

Shape and flow rate of the Duratec 35's Intake may have a significant impact on fuel engine efficiency.

Intake manifolds on common factory engines may be enhanced by a performance modification, however some manufacturers make pretty well engineered intake manifolds.

Increased power can be obtained by installing an upgraded Duratec 35 big valve conversion, as well as by enlarging port diameters and increasing head flow rates on the existing Duratec 35.

Turbo upgrades

NA (naturally aspirated) 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 significant power gains.

We've seen guys spending a fortune on turbocharger upgrades on the Duratec 35 only to suffer the indignity of watching the whole thing go up in smoke soon after it's first rolling road session.

Big turbos commonly suffer no power at low rpm, and small turbos spool up much more quickly but won't have the top end engines power gains.

Thanks to progress the choice of turbos is always evolving and we now see variable vane turbos, where the vane profile is altered according to speed to lower lag and increase top end torque.

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

You'll commonly see there is a limit in the air flow sensor MAP/MAF/AFM on the Duratec 35 when a lot more air is being drawn into the engine.

Going up you'll find 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor sapped bhp and torque at a much lower level.

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

Fuelling Upgrades

You will need to ensure that the engine is not starved of fuel so will have to look at the fuelling when you start going beyond 20% of a torque increase. Fuel pressure boost valves raise the fuel pressure, providing a more snappy throttle response.It makes sense to over specify your flow rate on the injectors.

The rule of thumb is to add 20% when specifying an injector, which takes into account injector deterioration and gives 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.

Performance Exhausts

It is recommended that you consider upgrading your exhaust if the current exhaust is causing a bottleneck.

The exhaust flow rate on most factory exhausts should be enough even with minor power increases, but if you begin to push the power levels higher, you will need to upgrade to a higher flowing exhaust.

The biggest exhaust you can find will decrease the exhaust flow rate, so avoid going with the largest exhaust you can find - the best for power improvements is generally between 1.5 and 2.5 inches. It is the design and structure, rather than the hole size, that is important.

Because of its higher size and surface area, modifications such as a sports catalyst for road-going vehicles essentially eliminate this constraint, allowing the vehicle to perform at levels that would be expected even if the catalyst were not fitted.

Because of the increased interior surface area and design, the car remains road legal and will flow much more smoothly as a result.

Due to the fact that removing a catalyst from a road-registered vehicle is prohibited in most countries and locations (and in some, you cannot even exchange a functional catalyst), the alternative test pipe mod or cat removal should be regarded an off-road only modification.

Weak spots, Issues & problem areas on the Duratec 35

The Duratec 35 engines are generally reliable and solid as long as they are looked after and serviced.

The internal position of the waterpump has been blamed for many water pump related issues. Later engines in the Duratec family reverted to an external water pump for this reason. Keep a close eye on engine temps, if this engine block overheats you will have problems and when this happens an engine open waterpump replacement is essential.

Also the water pump can leak water into the engine itself causing all manner of problems. Drops in coolant level are the only symptom you will get early on, and you might notice the mayonnaise color emulsion forming in the engine oil.

Carbon build up in the head, particularly around the valves which will reduce power and smooth running, this is a larger issue on direct injection engines but should be looked out for on all engines. We have tips on removing carbon To minimize this risk only use quality fuel and don't short journeys.

Regular oil changes are vital on the Duratec 35, and more importantly so when the car is tuned and will help ensure reliability of the engine.

If you want to disover more, or just get more pointers on Tuning your Duratec 35 engine please join us in our friendly forum where you can discuss Duratec 35 tuning options in more detail with our Duratec 35 owners. It would also be worth reading our unbiased Ford tuning articles to get insights into each modification and how effective they will be.

Please help us improve these tips by sending us your feedback in the comments box below.

We love hearing what our members have got up to and which tuning mods work best for them on each model of car. We use your comments and feedback to improve the accuracy of these Duratec 35 tuning guides which get regular updates and revisions.

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