PSA TU Tuning

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

The PSA TU are awesome to work on and with carefully chosen modified mods like ECU maps, turbo kits and camshafts you will substantially maximize your driving fun.

The TU engine is related to the X-Type engine sharing an OHC but instead of a chain it uses a cambelt and the transmission outputs were different making engine swaps to the TU from the X-type a challenge.

A diesel varient the TUD was also created from this same block design.

In this article we outline options for your TU tuning and provide tips on the greatest upgrades.

History, Power & Specs of the Engine

  • TU9 M/Z 50 PS (37 kW; 49 hp)
  • TU9/K 45 PS (33 kW; 44 hp)
  • TU1 F2/K 60 PS (44 kW; 59 hp)
  • TU1 JP 60 PS (44 kW; 59 hp)
  • TU1 M/Z 60 PS (44 kW; 59 hp)
  • TU1/K 55 PS (40 kW; 54 hp)
  • TU24 (M4A) 95 PS (70 kW; 94 hp)
  • TU24 (M2A) 103 PS (76 kW; 102 hp)
  • TU2 J2/Z (MFZ) 100 PS (74 kW; 99 hp)
  • TU3 A 75 PS (55 kW; 74 hp)
  • TU3 A/K 70 PS (51 kW; 69 hp)
  • TU3 F2/K 75 PS (55 kW; 74 hp)
  • TU3 FJ2/K 100 PS (74 kW; 99 hp)
  • TU3 FJ2/Z 95 PS (70 kW; 94 hp)
  • TU3 JP (in use after 2007 in Iran and China) 75 PS (55 kW; 74 hp)
  • TU3 M/Z
  • TU3 S85 PS (63 kW; 84 hp)
  • ET3 J4 (KFU)90 PS (66 kW; 89 hp)
  • TU5 J2/L3 (NFW) 105 PS (77 kW; 104 hp)
  • TU5 J4 (NFX) 120 PS (88 kW; 118 hp)
  • TU5 JP4 (NFU) 112 PS (82 kW; 110 hp)
  • TU5 JP4S (NFS) 125 PS (92 kW; 123 hp)
  • TU5 JP/L4 (NFT) 98 PS (72 kW; 97 hp)
  • TU5 JP+ (NFV) 95 PS (70 kW; 94 hp)
  • TU5 JP (NFR/NFZ) 90 PS (66 kW; 89 hp)
  • EC5 (w/ VVTi) (NFN) 122 PS (90 kW; 120 hp)
  • EC5 F/PG (NFP) 116 PS (85 kW; 114 hp)

Tuning the PSA TU and best TU performance parts.

Best TU tuning parts

The best TU upgrades on an engine are typically the ones that give the biggest return for your cash.

Just because you can do something it doesn't mean you should, and we would point out here than spending money trying to tune the under 90hp engines is generally a waste of time effort and money.

The power gains are so small and often lead to disappointment so stick with improving the handling and weight reduction if this applies to you.

If every mod out there adds 10% power and you only have 90 to start with that's a lot of money for a 9hp gain. Whereas the larger powered engines give a better return.

We won't be swayed by popular TU upgrades, they need to be cost effective.

The camshaft profile plays a big part in the engines power output so camshaft upgrades make quite a large difference.

The intake & exhaust durations (valves and valve lift) will alter depending on the chosen camshaft profile, so large torque gains are on offer for camshaft upgrades.

Fast road cams normally bump the torque through the rev band, you may lose a little bottom end torque but the top end will be higher.

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

A Motorsport and race cam is not great on the daily commute, because the lumpy idle will make the car prone to stall and smooth driving at low rpm becomes impossible. If you are developing a track car this doesn't matter as you are in the high end of your RPM range anyway and that is where you want the power to be.

Sourcing a decent cam for the TU is the challenge in most areas.

One option might be to get a stock cam reground to a fast road profile, but avoid going too extreme, it will ruin the car's low end power and idling, making it a challenge to drive in traffic.

You should ideally optimize your power band to the typical usage of your car so for a car used daily stick with a shorter duration TU cam

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

The ECU mapping and fuel pump and injectors also will make differences on the torque gains you'll hit.

Longer 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.

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Best mods for your TU

  1. Forced induction upgrades - forced induction is the most efficient approach to increase air supply, allowing you to burn more fuel and make more power. Although one of the most costly upgrades it offers big gains.
  2. Mapping - A remap provides the biggest gains compared to cost, aftermarket ECUs, and Tuning boxes are all alternatives.
  3. Fast road cams are are often the best upgrade for an engine, but they must be setup 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.
  4. Head work - The goals of porting and flowing the head are to get air flowing into the engine while removing flow restrictions and turbulence.
  5. Intake Upgrades and Sports Exhausts - Please note that on their own these mods won't ADD POWER in most cases, but they can help enhance power after other mods by removing the restriction.

TU Tuning Stages

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

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

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

Plan your options and then find your upgrades and set yourself a power target to avoid wasting your time and money.

ECU mapping helps fully realize the full potential of all the parts you've done to your TU.

(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 NA (naturally aspirated) engines, but your results may rely on the parts you've done and the condition of your engine.

It is the main goal to any car tuning task to push air into the TU engine

Intake flow the air from the air cleaner and allow it to be fed into the engine and mixed with fuel.

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

Many mass-produced engine plenum chambers are improved through an upgrade, although some manufacturers provide fairly well-optimized plenum chambers.

Adding a TU larger valve kit, doing some port work and head flowing will also boost bhp, and importantly will give you an improved bhp increase on other tuning parts.

TU 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 TU

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 the engine is fitted with a turbocharger mods are going to make more power and most turbo engines will have better components.

There are weak spots for every engine, with some being over specified and some just sufficiently able to handle stock power

Discover these limitations and upgrade to stronger pistons, crank and engine components to handle the power.

We see many people spending a loads on turbo charger upgrades on the TU only to have the engine literally blow up on it's first outing after it's first rolling road session.

Larger turbochargers tend to experience low end lag, and smaller turbochargers spool up quickly but don't have the high rpm power band gains.

Over the last 20 years the choice of turbo chargers is always developing and we commonly find variable vane turbo chargers, permitting the vane angle is altered according to speed to lower lag and increase top end torque.

Twin scroll turbo chargers divert the exhaust flow into 2 channels and flow these at differently angled vanes in the turbo. They also increase the scavenging effect of the engine.

You'll commonly see there is a restriction in the air flow sensor (AFM/MAF/MAP) on the TU when a lot more air is being pulled into the engine.

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

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

TU Fuelling

When you raise the bhp and torque you will need to ramp up the fuelling. A pressure boost valve will improve throttle response and a throttle body upgrade or individual throttle body conversion will help lift your car's ability to burn fuel by icreaseing the scope for more air.

More bhp and torque needs more fuel.

Most tuners we speak with say to be generous with your injector capacity.

As a rule of thumb add 20% to the flow rate when fitting an injector, which takes into account injector deterioration and provides 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.

All the following flywheel power targets will assume an injector duty cycle of 80% and a base of 58psi of fuel pressure at idle.

4 Cylinder NA (naturally aspirated) engines

  • 58 PSI 285cc/min 200hp
  • 58 PSI 426cc/min 300hp

4 Cylinder supercharged engines

  • 58 PSI 312cc/min 200hp
  • 58 PSI 468cc/min 300hp

Exhaust mods for the TU

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

On most factory exhausts you'll find your 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 can help increase the flow of gases through the engine.

But if your exhaust is too large, ie: over 2.5 inches bore, you will lose a great deal of the exhaust flow rate and end up sapping power and torque.

Usual exhaust restrictions can be traced to the catalysts installed around 1990, so adding a freer flowing performance catalyst removes the restriction.

We note that performance cats perform similarly to decats and have the added benefit of keeping your car street legal, as decats or catalyst removal is illegal in most territories for road going cars.

Weak spots, Issues & problem areas on the TU

The TU engines are generally reliable and solid units, as long as you follow the manufacturers service schedules, and use a good quality oil to ensure longevity. Few problems should happen 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 TU, 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 TU engine please join us in our friendly forum where you can discuss tuning options in more detail with our TU 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 upgrades work best for you on your car. Which helps us keep our guides and tips up to date helping others with their modified car projects. Your feedback and comments are used to keep this page up to date, and help improve the accuracy of these TU tuning guides which get regular updates and revisions.

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