Tuning the Nissan GA

"Comprehensive guide to performance tuning the Nissan GA engine!"

The Nissan GA really good project engines and with carefully picked sports upgrades like ECU maps, turbo upgrades and camshafts you will definitely maximise your driving pleasure.

TorqueCars will detail the best approach to GA tuning and summarise the ultimate mods that work.

The top GA modifications on an engine are typically the ones that give the best power gain for you spend.

We won't be swayed by popular GA modifications, they need to be cost effective.

Significant gains on the GA can be made from camshaft upgrades. Altering the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the bhp and power output.

NB: Fast road cams usually bump the performance over the rev range, you may sacrifice a little bottom end power but the high end rpm power will improve.

Race 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 Competition cam makes it harder when driving around busy urban areas.

You should ideally match your engines power to your preferences so for a car used daily stick with a fast road GA cam

Each engine responds better to more or less aggressive camshaft durations check your engine on a rolling road.

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

Altering 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.

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

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

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

A remap helps unlock the full potential of all the tuning mods you've fitted to your GA.

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 may rely on the tuning mods you've carried out and the condition of your engine.

It is the whole point to any engine performance tuning task to force more air and fuel into the GA engine

Intake manifold take the air during the suck phase from the filter and allow it to be drawn into the engine and mixed with fuel.

Design and rate of flow of the Plenum can make a noticeable difference to to fuel engine efficiency on the GA.

Many mass produced engine plenum chambers are in dire need of a performance upgrade, although some manufacturers provide fairly well optimized plenum chambers.

Fitting big valve kits, doing some port matching and head flowing will also improve bhp, & more importantly will afford you increasing the bhp increase on other tuning 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 GA

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

If your motor is turbo charged upgrades are more reliable and turbo charged engines are made using more solid components.

There are practical limits for every engine, with some being incredibly solid and some only able to handle stock power

We recommend you find these limits and install better quality components to survive the power.

It's not unheard of people spending a lots of money on turbo charger upgrades on the GA only to watch the car throw a rod just after it's completed.

Large turbo units often experience no power at low rpm, and little turbo units spool up really quickly but won't have the peak rpm bhp gains.

Over the last 20 years the world of turbo units is always moving on and we are seeing variable vane turbo units, permitting the vane angle is altered according to speed to lower lag and increase top end power.

Twin scroll turbo units divert the exhaust gases into two channels and flow these at differently profiled vanes in the turbo. They also improve the scavenging effect of the engine.

It is not unusual that there is a limitation in the air flow sensor MAP/MAF/AFM on the GA when loads more air is being fed into the engine.

You'll see that 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 power gains, although more complex to get working. We have this guide to twinchargers if you want to read more.

Fuelling upgrades and mods

When you improve the bhp and torque you will need to uprate to the fuel system.

More bhp and torque needs more fuel. It is important to over specify your injector capacity.

As a rule of thumb add 20% when buying an injector, this accounts for injector deterioration and allows 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.

Exhaust upgrades and mods

You only need to to upgrade your exhaust if your current exhaust is actually causing a flow problem.

On most factory exhausts you should find that your flow rate is still fine 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 generally help improve air flow from the engine but avoid an exhaust that is too large or you may end up will reduce the flow rate. Stick to 1.5 to 2.5 inches for best results.

Usual exhaust restrictions typically happen through the catalyst and or DPF filters which manufacturers fit, especially as they start to get worn and carbon builds up, so adding a higher flowing race alternative will help avoid this restriction.

Weak spots, Issues & common problem areas on the GA

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

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

History of the Engine

GA13

• GA13S SOHC Carb 12 valve 79hp
• GA13DS DOHC Carb 16valve 78hp
• GA13DE DOHC fuel injection 84hp

GA14

• GA14S SOHC Carb 12 valve 79 hp 
• GA14DS DOHC Carb 16valve 74hp
• GA14DE DOHC fuel injection  101 hp

GA15

• GA15S SOHC Carb 12 valve 84hp
• GA15DS DOHC Carb 16valve 93hp
• GA15E SOHC fuel injection 96 hp
• GA15DE DOHC  fuel injection 104 hp

GA16

• GA16S SOHC Carb 12 valve 94 hp
• GA16E SOHC fuel injection 110 hp
• GA16i DOHC fuel injection 90 hp
• GA16DE DOHC  fuel injection 16 valves 110 hp
• GA16DE DOHC  fuel injection 16 valves 102 & 115hp USA
• GA16DS  DOHC 16 valves  electronically controlled carburetor & catalyst 89 hp
• GA16DNE DOHC 16 valves  electronically controlled carburetor & catalyst 105 hp Mexico & Asia

For more information on Tuning your GA engine please join us in our friendly forum where you can discuss tuning options in more detail with our tuning articles to get a full grasp of the benefits and drawbacks of each modification.

We need your help improving this article, so please send us your feedback in the comments box below and pass on any tips, points or facts we have wrong or have not covered.

We really like hearing from our readers, and hearing about which tuning parts were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our GA guides and tips are kept up to date.

Please Check out my YouTube channel, we're regularly adding new content...

Click to accept YouTube Cookies & Play.

This article is flagged for an update, so please pass on specific tips below that I can include. All articles, and content was written by me, Waynne Smith TorqueCars founder. Some outlines are just too general so I appreciate your feedback and suggestions. This entry was filed under Nissan. You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

If you liked this page please share it with your friends, drop a link to it in your favourite forum or use the bookmarking options to save it to your social media profile.