Tuning the Alfa Romeo JTS

"All you need to know about tuning and performance parts on the Alfa Romeo JTS engine!"

Carref prides itself on providing the latest tips and guides to your modification project.

TorqueCars will review and look at JTS tuning and outline the premier modifications. Alfa Romeo JTS great bases for a tuning project and with the right performance modifications like a remap, turbo improvements and camshafts you will positively maximise your driving pleasure.

We provide a guide to JTS tuning and summarise the ultimate modifications. Alfa Romeo JTS make awesome project engines and with carefully chosen modified upgrades like ECU maps, turbo improvements and camshafts you will definitely improve your driving opportunities.

We rely on our visitors to pass on tips and tell us about their projects and what worked on their car, and this article is the culmination of the feedback we have received. First let us look at the history and specs of this engine and then consider which tuning modifications work best on it.

History of the Engine

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 lb⋅ft) @ 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.)

• 2005–2010 Alfa Romeo 159
• 2005–2010 Alfa Romeo Brera
• 2006–2010 Alfa Romeo Spider

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)

• 2005–2010 Alfa Romeo 159
• 2005–2010 Alfa Romeo Brera
• 2006–2010 Alfa Romeo Spider

Tuning the Alfa Romeo JTS and best JTS performance parts.

What are the most effective JTS parts

Just because particular upgrades are appear in lots of JTS projects it doesn't mean it is good, we shall best upgrades that will give your JTS the best value for money to power increase.

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 power band gains are on offer for cam upgrades.

Fast road cams normally bump the bhp through the rpm band, you may sacrifice a little low end bhp but the higher rpm power will be lifted.

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

A Competition cam will just annoy you whilst driving in heavy traffic.

You should ideally match your engines power to your usage of the car so for a car driven daily stick with a shorter duration JTS cam

Different JTS engines respond better to mild cam durations so set your engine up on a rolling road.

The map and injectors and fuel pump also have a large bearing on the bhp gains you'll make.

Longer valve durations can alter the bhp 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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Modifying to Stage 1:

 Fast road camshaft, Drilled & smoothed airbox, Sports exhaust manifold, Remaps/piggy back ECU, Panel air filters, Intake headers.

Modifying to Stage 2:

 high flow fuel injectors, fuel pump upgrades, induction kit, Fast road cam, Ported and polished head, Sports catalyst & performance exhaust.

Modifying to Stage 3:

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

ECU flashing should help to to establish the full potential of all the tuning parts you've done to your JTS.

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

Pushing fuel and air into the JTS engine is the main goal to any engine performance tuning task.

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

Shape and rate of flow of the Intake headers can make a substantial effect on to fuel mixing and power on the JTS.

It's not uncommon that intake manifold are in dire need of a performance upgrade, although a few makers provide well optimised intake manifold.

Larger JTS valves, doing a bit of port matching and head flowing will also improve performance, the fantastic side effect is it will give you increasing the performance increase on other tuning mods.

Which turbo upgrades are best?

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 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.

We see many people spending a lots of money on turbo upgrades on the JTS only to suffer the humiliation of seeing the engine block explode soon after it's finished.

Larger turbos often experience a bottom end lag, and low capacity turbos spool up much more quickly but won't have the high rpm torque gains.

Thankfully the market of turbochargers is always moving on and we are seeing variable vane turbochargers, where the vane profile is altered according to speed to lower lag and increase top end bhp and torque.

Twin scroll turbochargers divert the exhaust gases into a couple of channels and direct these at differently designed vanes in the turbo. They also improve the scavenging effect of the engine.

It is not unusual that there is a restriction in the air flow sensor MAP/MAF/AFM on these engines when loads 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 limited torque at a much lower level.

Adding a supercharger or additional turbo will make large power gains, although more challenging to get working. We have this guide to twinchargers if you want to read more.

Fuelling

You will need to ensure that the engine is not starved of fuel so need to look at the fuelling when you start extending past 20% of a bhp and torque increase.When it comes to your injectors flow rate you need some spare capacity, so don't calculate which injector and fuel pump setup will match your needs exactly or you'll have flat spots and fuelling issues and problems.

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

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 NASP engines

• 58 PSI 285cc/min 200hp
• 58 PSI 426cc/min 300hp
• 58 PSI 568cc/min 400hp

Choosing the right performance exhaust

One of the most common mistakes and problems we see in tuning projects is usually down to the exhaust, or rather a poorly chosen exhaust for your engine.

You may need to uprate your exhaust if the existing exhaust is actually creating a restriction in flow.

On most factory exhausts you'll see your 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.

Please dont run with the largest exhaust you can find this will slow the exhaust 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.

Typically exhaust restrictions come around the catalyst installed, so adding a better flowing high performance alternative will help avoid this restriction.

Weak spots Issues & problem areas on the JTS

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

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

For more information on Tuning your JTS engine please join us in our friendly forum where you can discuss tuning options in more detail with our worldwide members, or read our 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 JTS articles which are continually updated.

This article was written by Waynne Smith on TorqueCars, and I appreciate your feedback and suggestions. This entry was filed under Alfa Romeo. You can leave a response below or join TorqueCars forum to discuss this article and car modification in detail with our members.

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