Tuning the Alfa Romeo JTS

"Comprehensive guide to performance tuning the Alfa Romeo Alfa JTS engine!"

We are always getting messages about the best Alfa JTS modifications. So let us look into Alfa Romeo Alfa JTS modifications and outline the best mods that work on this great engine and point out some frequent tuning mistakes along the way.

Let us look at Alfa JTS tuning and provide tips on the premier modifications for your car. Alfa Romeo Alfa JTS are fantastic to work on and with carefully chosen motorsport upgrades like a remap, turbo improvements and camshafts you will dramatically maximise your driving experience.

When talking about the best parts for your Alfa JTS engine, we are going to concentrate on the parts that give the best power gain for you spend.

Altering your Alfa JTS camshaft will make a dramatic difference to the engine power band. Choosing a higher performance camshaft profile raises the power band accordingly.

NB: Fast road cams usually bump the bhp over the rpm range, you might lose a little low down bhp but the high end rpm power will be better.

Motorsport 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 cam makes it harder when driving in heavy traffic.

You should ideally match your bhp range to your usage of the car so for a daily driver stick with a mild fast road Alfa JTS cam

Different Alfa JTS engines respond better to less aggressive cam durations check your engine on a rolling road.

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

A longer valve duration 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.

Alfa JTS Best Tuning Mods & Upgrades

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Guide to the best tuning mods & Upgrades

  1. ECU Map Tuning & Remaps

    Some cars may require a piggyback ECU's or aftermarket ECU's to change the OEM map, but remapping is the most vital step of your tuning project to fully maximise your mods. Expect 10-20% on NASP engines and 30-40% on turbocharged units.

  2. Strengthen Your Engine

    Tuned cars will show up weaknesses, typically in the turbochargers, clutch and internal engine components. Whilst most engines can cope with mild tuning mods, TorqueCars recommend that you upgrade the internal components before these weak spots manifest themselves.

  3. Mods that Remove a Restriction

    A restricted intake or exhaust will have an impact on your performance, so use a better flowing air filter/induction kit and better flowing exhaust (sports cats where legal are a good option) whenever your tuning creates a flow restriction. Turbo engines also benefit from intercooler upgrades as these resist heat soak for longer periods of time.

  4. Mods that Improve Fuelling

    Every tuning project will aim to increase the air supply, but fuel supply is just as vital and will need to match the air the engine can utilise,  a fuel pump and injector upgrade are usual mods, but also in many cases the fuel regulator will need improvement.

  5. Mods to Provide better Airflow

    Increasing the air supply is just as essential as improving fuelling, we suggest you look at head mods (flowing and porting, 5 angle valve jobs), fit bigger valves, fast road cams and forced induction upgrades (adding a better flowing turbo) to improve air intake.

Tuning Stages

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

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

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

The Alfa JTS engine blocks are fantastic to work on and thanks to their popularity there is a growing number of modifications and performance parts out there.

ECU flashing will help fully realize the full potential of all the tuning parts you've done to your Alfa JTS.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but figures achieved usually differs on the tuning parts you've carried out and the condition of your engine.

It is the main goal to any engine tuning job to pull more air and fuel into each cylinder

Air Intake manifolds transmit the air during the suck phase from the air cleaner and allow it to be fed into the engine and mixed with fuel.

The size of bore and shape and rate of flow of the Air Intake manifolds can make a noticeable effect on to fuel engine efficiency on the JTS.

We often see intake are needing aftermarket parts, although a few car makers provide reasonably well designed intake.

Adding a Alfa JTS larger valve kit, getting Alfa JTS port enlargement and head flowing will also lift torque, and significantly will afford you raising the torque increase on other upgrades.

Turbo upgrades for the JTS

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 Alfa JTS

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

If the engine is turbocharged, tuning mods are going to net you a larger power gain and you'll see that turbocharged engines are built using uprated components.

There are practical limits for every engine, with some being extremely strong and some only just able to handle stock power

See where you'll find these limits and fit forged components to cope with the power.

It's not unheard of guys spending a a stack of money on turbo charger upgrades on the Alfa JTS only to suffer the indignity of watching the car explode just after it's been enthusiastically driven.

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

Over the last 20 years the choice of turbo units is always improving and we now see variable vane turbo units, where the vane angle is altered according to speed to lower lag and increase top end bhp.

Twin scroll turbo units divert the exhaust gases into two channels and feed these at differently profiled 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 MAF/MAP on the Alfa JTS when a lot more air is being pulled into the engine.

You'll see that 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor sapped torque at a much lower level.

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

Uprating JTS fuel injectors

You will need to ensure that the engine is not starved of fuel so must increase the fuelling when you start exceeding 20% of a bhp and torque increase. Most tuners we speak with say to be generous with your flow rate on the injectors.

The rule of thumb is to add 20% capacity when fitting an injector, helps cope with injector deterioration and provides 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 Alfa JTS performance exhausts

You should look to boost your exhaust if the current exhaust is creating a flow problem.

On most factory exhausts you should find that 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.

Don't go with the largest exhaust you can find you'll slow up the exhaust flow rate - the best for power gains are usually between 1.5 to 2.5 inches. It is the shape and material more than the bore size.

Usual exhaust restrictions are in the catalyst and filters installed, so adding a better flowing race alternative will help avoid this restriction.

Specs, applications and bhp lbft on the Alfa JTS

This engine came as a straight for and V6 configuration and  interestingly JTS stands for Jet Thrust Stoichiometric, which is Alfa's version of direct injection. It was based on the twin spark and offered quite a bit more power across the rev range.

1.9 L (1,859 cc) 2005–2011 158 hp) @ 6500 rpm 140 lbft) @ 4500 rpm

Alfa Romeo 159

2.0 L (1,970 cc) 162 hp @ 6400 rpm 152 lbft@ 3250 rpm

  • 2002-2005 Alfa Romeo 156
  • 2003-2004 Alfa Romeo Spider & GTV
  • 2004–2010 Alfa Romeo GT

2.2 L (2,198 cc) 182 hp @ 6500 rpm 170 lbft@ 4500 rpm (Based on the Ecotec block.)

3.2 L (3,195 cc) 256 hp at 6200 rpm  237 lbft at 3800 rpm (Based on the GM high feature engine and modified by Alfa)

Tuning the Alfa Romeo JTS and best JTS performance parts.

Problems and issues to look out for on the Alfa JTS

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

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

For more information on Tuning your Alfa JTS engine please join us in our friendly forum where you can discuss tuning options in more detail with our Alfa JTS owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

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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 Alfa JTS guides and tips are kept up to date.

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