Tuning the GM Family 0

"Comprehensive guide to performance tuning the GM Family 0 engine!"

TorqueCars will review Family 0 tuning and summarise the best modifications. GM Family 0 provide a fun base for your project and with the right uprated upgrades like a remap, turbo improvements and camshafts you will positively maximize your driving fun.

When talking about the best best for your Family 0 engine, we are going to focus on the upgrades that give the biggest return for your cash.

The camshaft profile plays a big part in the engines power output so camshaft upgrades make quite a large difference. The intake and exhaust durations will alter depending on the chosen camshaft profile, so large bhp gains are on offer for camshaft upgrades.

NB: Fast road camshafts tend to boost the bhp and torque over the rpm band, you could sacrifice a little low down power but the higher rpm power will improve.

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

In a typical daily driver should ideally to match your engines power to your driving style.

You will never have found a Family 0 Motorsport camshaft is a pleasure to live with when on the daily commute.

Some Family 0 engines respond better to extreme cam durations than others.

The engine timing and injectors and fuel pump also will say much on the power gains you'll hit.

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.

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

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

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

Carefully think through your options and then buy your mods and set yourself a power target to avoid disappointment.

Remaps should help to fully realize the full potential of all the mods you've fitted to your Family 0.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but the end result often depend much on the mods you've applied and the condition of your engine.

Pulling more air and fuel into your Family 0 is vital to any performance tuning project.

Intake flow the air from the filter and allow it to be fed into the engine cylinders.

The size of bore and shape and rate of flow of the Intake headers can make a large effect on to fuel delivery on the Family 0.

Most intake are in dire need of an upgrade, although some OEM provide well optimised intake.

Big valve conversions on the Family 0, carrying out Family 0 port enlargement and head flowing will also improve performance, & importantly will give you a better performance increase on other mods.

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 Family 0

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

When your car has a turbo already fitted parts are going to net you a larger power gain and we find turbo engines use stronger components.

However every engines have weakspots

We recommend you find these restrictions and fit better pistons and crank to handle the power.

We've seen people spending a fortune on turbocharger upgrades on the Family 0 only to watch the engine literally blow up when it's finished.

Big upgraded turbo units often experience a bottom end lag, and little turbo units spool up quickly but do not have the high rpm bhp gains.

Thanks to progress the world of turbochargers is always moving on and we are seeing variable vane turbochargers, permitting the vane angle is altered according to speed to lower lag and increase top end power.

Twin scroll turbochargers divert the exhaust flow into two channels and direct these at differently designed vanes in the turbocharger. They also improve the scavenging effect of the engine.

It is common that there's a restriction in the air flow sensor AFM/MAP on the Family 0 when loads more air is being drawn into the engine.

We see 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor sapped performance at a much lower level.

Adding a supercharger or additional turbo will make large bhp and torque gains, although more difficult to configure. We have this guide to twinchargers if you want to read more.

Fuelling upgrades and mods

When you boost the power you will need to ramp up to the fuel system.

More power needs more fuel. It makes sense to over specify your flow rate on the injectors.

As a rule of thumb add another 20% when fitting an injector, this takes into account 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.

Exhaust upgrades and mods

You may need to increase your exhaust if your current exhaust is creating a flow problem.

On most factory exhausts you should find that the 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.

Don't go with the widest exhaust you can find this will 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.

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

Weak spots, Issues & common problem areas on the Family 0

The Family 0 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the Family 0, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

History of the Engine

Generation I

  • 1.0 L (973 cc)
    X10XE 40.5 kW (55 PS) 82 Nm (60 lbft) @2800rpm
    Z10XE 42.7 kW (58 PS) 85 Nm (63 lbft
  • 1.2 L (1,199 cc)
    X12XE 48 kW (65 PS) @5600rpm 110 Nm (81 lbft @4000rpm
    Z12XE  55 kW (75 PS) @5600rpm 110Nm(81 lbft @4000rpm

Generation II

This second generation saw a twin port design, allowing better torque and fuel economy and the crank and oilways were revised.

  • 1.0 L (998 cc)
  • Z10XEP 44 kW (59 hp) @5600rpm 88 Nm (65 lbft @3800rpm
  • 1.2 L (1,229 cc)
  • Z12XEP 59 kW (79 hp) @5600rpm 110 Nm (81 lbft @4000rpm
  • 1.4 L (1,364 cc)
  • Z14XEP 66 kW (89 hp) @5600rpm 125Nm(92 lbft @4000rpm

Generation III

This third generation EcoFlex engine takes the twin port concept and improves upon it. They added double cam phasing as well and we also saw a turbocharged version added and stop start technology.

1.0 L (998 cc)

  • A10XEP (LDB) 48 kW (64 hp) @5300rpm 90 Nm (66 lbft @4000rpm
    1.2 L (1,229 cc)
  • A12XEL (LWD) 51 kW (68 hp) @5600rpm 115 Nm (85 lbft @4000rpm
  • A12XER (LDC) 62 kW (83 hp) @5600rpm 115 Nm (85 lbft @4000rpm

1.4 L (1,398 cc)

  • A14XFL (LUU) 63 kW (84 hp) @4800rpm 126 Nm (93 lbft @4800rpm
  • A14XEL (L2Z) 64 kW (86 hp) @6000rpm 130Nm(96 lbft @4000rpm
  • A14XER (LDD) 74 kW (99 hp) @6000rpm 130Nm(96 lbft @4000rpm
  • A14XFR (L2N) 74 kW (99 hp) @6000rpm 130Nm(96 lbft @4000rpm

1.4 L (1,364 cc)

  • A14NEL (LUH) 88 kW (118 hp) @4800–6000rpm 200 Nm 148 lbft @1850–4200rpm 220Nm162 lbft (Overboost)
  • A14NET (LUJ) 103 kW (138 hp) @4900–6000rpm 200 Nm 148 lbft @1850–4900rpm 220Nm162 lbft (Overboost)
  • U14NFT (LUJ) 103 kW (138 hp) @4900–6000rpm 200 Nm (148 lbft @1850–4900rpm 220Nm162 lbft (Overboost)
  • U14NFT (LUV) 103 kW (138 hp) @4900rpm 200 Nm 148 lbft @1850 or 2500rpm
    U14NFT (LUV - Vanderhall) 134 kW (180 hp) @4950rpm 250Nm 184 lbft @2450rpm

For more information on Tuning your Family 0 engine please join us in our friendly forum where you can discuss tuning options in more detail with our Family 0 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 modifications were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our Family 0 guides and tips are kept up to date.

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