PSA DT17/DT20 Tuning

"All you need to know about tuning the PSA DT engine!"

The PSA DT make a good tuning project and with carefully picked sports modifications like ECU maps, turbo improvements and camshafts you will positively maximize your driving enjoyment.

Our aim here is to examine the options for your DT17/DT20 tuning and show the best upgrades.

History, Power & Specs of the Engine

Built through a venture with Ford, Jaguar and LandRover the Lion engine V6 diesel was conceptualised. (Other brands badged this the AJD V6)

DT17 — 2.7 L (2,720 cc)
DT20 — 3.0 L (2,993 cc)

Tuning the PSA DT and best DT performance parts.

Best DT17/DT20 upgrades

When talking about the best modifications for your DT engine, we are going to focus on the parts that give the biggest return for your cash.

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

Fast road camshafts commonly push up the performance over the rev range, you may lose a little low end power but the top end will improve.

Competition camshafts, push up the top end band but as a result the car will not idle smoothly and low end power nearly always suffers.

In a typical daily driver must carefully try to match your engines power to your typical driving style.

I'd be shocked if you'd have ever thought or claimed that a DT Race camshaft is a pleasure to live with when driving around busy urban areas. This is because a competition cam causes a very lumpy idle, and makes the car more prone to stall or jerk along in stop start traffic, sadly though many ignore this and end up ruining a perfectly good car and having to revert back to a fast road, or OEM cam profile.

Different DT engines respond better to more aggressive cam durations so set your engine up on a rolling road.

The engine timing and fuelling also have an effect on the power gains you'll make.

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.

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

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

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

The DT engines respond well to upgrades and thanks to their popularity there is a growing number of modifications and performance parts around.

ECU mapping allows a tuner to release the full potential of all the modifications you've done to your DT.

(In some cases, as the factory ECU is locked flashing is not an option, so an aftermarket ECU is the route to take, and many of these will outperform factory ECU's but make sure it has knock protection and that you get it setup properly.)

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

It is the whole point to any tuning task to force fuel and air into your DT

Air Intake manifolds flow the air from the air filter and allow it to be pulled into the engine cylinders.

The shape and flow characteristics of the Intake can make a big improvement to fuel mixing and power on the DT.

Many mass produced engine plenum chambers are improved through aftermarket parts, although some manufacturers provide fairly well optimized plenum chambers.

Adding a DT larger valve kit, doing some DT port enlargement and head flowing will also increase performance, and as an added benefit will make space for a better performance increase on other parts.

Turbo upgrades

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 DT

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.

When your motor is fitted with a turbocharger upgrades are relatively easy and we find turbo charged engines use uprated components.

There are tuning limits for every engine, with some being very over engineered and some just sufficiently able to handle stock power

See where you'll find these limitations and fit better pistons and crank to cope with the power.

We see many drivers spending a lot of money on turbocharger upgrades on the DT only to suffer the humiliation of seeing the engine block throw a rod on it's first outing after it's been enthusiastically driven.

Big turbos will usually suffer low end lag, and small turbos spool up much more quickly but do not have the peak rpm torque gains.

Over the last 20 years the choice of turbos is always developing and we now see variable vane turbos, where the vane profile is altered according to speed to lower lag and increase top end power.

Twin scroll turbos divert the exhaust flow into a couple of channels and feed these at differently profiled vanes in the turbo. They also help the scavenging effect of the engine.

It is not unusual that there's a limit in the air flow sensor AFM/MAF on the DT when a lot more air is being sucked into the engine.

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

Adding a supercharger or additional turbo will make large torque gains, although harder to get working. We have this feature on twinchargers if you want to read more.


Don't overlook the need to uprate the fuel system when you are increasing the bhp - it makes the car more thirsty. Don't forget to be generous with your flow rate on the injectors.

As a rule of thumb add 20% to the flow rate when buying an injector, this allows for injector deterioration and affords 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.


Only look to increase your exhaust if the existing exhaust is creating a flow problem.

On most factory exhausts you'll find the exhaust flow rate is 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 will certainly help air flow from the engine but do not go too wide or you might just stuff your flow rate and make things worse. So generally speaking, keep to a size of 1.5 to 2.5 inches for best results.

Common exhaust restrictions can be traced to the filters installed, so adding a better flowing race alternative such as a sports catalyst pretty much removes this restriction, thanks to it's larger size and surface area, and will effectively raise the performance to levels you would expect without having a catalyst installed, but keeps the car road legal.

Weak spots, Issues & problem areas on the DT

The DT engines are generally reliable and solid as long as they are regularly serviced and maintained.

Carbon build up in the head, particularly around the valves which will sap power or create flat spots, this is a larger issue on direct injection engines but should be looked out for on all engines. We have tips on removing carbon build up.

Some of our members have had issues with flat spots or glitches after applying mods and upgrades or tuning, this is not usually related to this engines design, so instead see our article on diagnosing flat spots and problems after tuning which should help you get the bottom of this issue.

Regular oil changes are vital on the DT, especially when tuned and will help extend the life and reliability of the engine.

If you would like to know more, or just get some friendly advice on Tuning your DT engine please join us in our friendly forum where you can discuss tuning options in more detail with our DT owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

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

We love to hear what our visitors have got up to and which mods work best for them on each model of car. Comments are used to improve the accuracy of these DT articles which are continually updated.

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Your Constructive comments on this article

One Response to “DT Tuning”

  1. Phill Glasson says:

    Great article, however I’m not looking to increase the top end of my DT17, what I want is to reduce the turbo lag. It nearly kills me every time I enter a roundabout, thinking I’ve got plenty of time, but the lack of throttle response is attrocious. What can I do to address that in my DT17?

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