Tuning the GM Family 1

"Comprehensive guide to performance tuning the GM Family 1 engine!"

The GM Family 1 provide a fun base for your project and with the ultimate performance mods like remapping, turbo kits and camshafts you will substantially enhance your driving pleasure.

Our aim here is to outline options for your Family 1 tuning and point out the best modifications for your car.

Just because particular mods are appear in lots of Family 1 projects it doesn't mean you should fit it, we shall best mods that will give your Family 1 the best power gain for you spend.

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

NB: Fast road camshafts normally push up the bhp across the rpm band, you may sacrifice a little bottom end bhp but the top end will be higher.

Race camshafts, push up the top end band but as a result the car will not idle smoothly and low end power nearly always suffers.

In a daily driver must carefully try to optimize your bhp range to your cars usage.

I'd be gobsmaked if you find a Family 1 Competition camshaft is a pleasure to live with when on the daily commute.

Some Family 1 engines respond better to extreme camshaft durations than others.

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

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.

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

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

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

Plan your options and then find your tuning parts and set yourself a power target to save yourself from expensive mistakes.

Mapping allows a tuner to release the full potential of all the upgrades you've fitted to your Family 1.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but your results may vary depending on the upgrades you've done and the condition of your engine.

Pushing air into each cylinder is vital to any engine upgrade project.

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

Design and flow rate of the Plenum can make a big improvement to fuel delivery on the Family 1.

Commonly we find the air intake manifolds are ripe for aftermarket parts, although a few car makers provide fairly well optimized air intake manifolds.

Big valve conversions on the Family 1, getting port work and head flowing will also raise bhp, and importantly will raise potential for raising the bhp 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 1

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

If the engine has a turbocharger parts are going to make more power and you will discover turbo engines use uprated components.

However you'll find engines have limits

Discover these limits and upgrade to better quality components to utilize the power.

There are many drivers spending a loads on turbo upgrades on the Family 1 only to watch the engine block throw a rod on it's first outing after it's been enthusiastically driven.

Big turbochargers tend to experience low end lag, and smaller turbochargers spool up really quickly but won't have the peak rpm torque gains.

In the last 10 years the choice of turbos is always developing and we now see variable vane turbos, permitting the vane profile is altered according to speed to lower lag and increase top end bhp and torque.

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

It is common that there's a limitation in the air flow sensor AFM/MAF on the Family 1 when a lot more air is being fed into the engine.

Going up you'll find 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 bhp and torque gains, although harder to configure. We have this article on twincharging if you want to read more.

Fuelling upgrades and mods

You will need to ensure that the engine is not starved of fuel so need to pay attention to the fuelling when you start extending past 20% of a bhp and torque increase.We would recommend you to over specify your injector capacity.

The accepted safe increase is to add another 20% when buying an injector, which takes into account injector deterioration and gives a bit of 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

Only look to increase your exhaust if the current exhaust is actually causing a restriction.

On most factory exhausts you'll see the exhaust 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 increase the flow of air through the engine.

But if the exhaust pipe is too large, ie: it's over 2.5 inches bore, you will lose a lot of the exhaust flow rate and end up lacking power and torque.

Common exhaust restrictions can be located the catalysts installed, so adding a better flowing race alternative will help avoid this restriction.

Weak spots, Issues & common problem areas on the Family 1

The Family 1 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the Family 1, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

History of the Engine

1.0 X10YFH

  • 78–80 bhp) at 6400 rpm  69–71 lbft) at 5200 rpm
  • Chevrolet Celta
  • Chevrolet Prisma
  • Chevrolet Corsa/Classic

1.2 Opel Corsa A Vauxhall Astra A

  • 12NV
    52hp 39 kW @ 800 rpm 63 lbft @ 2600 rpm
  • 12ST
    54hp 40 kW @ 600 rpm 90 Nm (66 lbft @ 2200 rpm
  • A12ST
    50hp 37 kW @ 600 rpm 88 Nm (65 lbft @ 2200 rpm
  • C12NZ
    45hp 34 kW @ 000 rpm 88 Nm (65 lbft @ 2400 rpm
  • S12ST
    54hp 40 kW @ 600 rpm 90 Nm (66 lbft @ 2200 rpm

1.3 Opel Ascona C  Opel Kadett D Opel Manta B Astra

  • 13N
    60hp 45 kW @ 800 rpm 69–71 lbft @ 3800 rpm
  • 13Nb
    60hp 45 kW @ 800 rpm 71 lbft @ 3200 rpm
  • 13S
    68–75hp 51–56 kW @ 800 rpm 71–74 lbft @ 3800–4600 rpm
  • 13SB
    70hp 52 kW @ 800 rpm 74 lbft @ 3800–4200 rpm
  • 13SH
    83hp 62 kW @ 800 rpm 80 lbft @ 4200 rpm

1.4

  • 14NV
    74hp 55 kW @ 600 rpm 80 lbft @ 3000 rpm
  • C14NZ
    60hp 45 kW @ 600 rpm 76 lbft @ 2600 rpm
  • C14SE
    82hp 61 kW @ 200 rpm 86 lbft @ 3400 rpm
  • X14YFL
    89–97hp 66–72 kW) at 6200 rpm 90–94 lbft
  • X14YFH
    99–105hp 74–78 kW) at 6000 rpm 95–97 lbft
  • N14YF
    97–102hp 72–76 kW) at 6000 rpm 93–97 lbft at 3200 rpm

1.6

  • C16NZ
    72–75hp 54–56 kW @ 200 rpm 92 lbft @ 2800 rpm
  • C16SE
    100hp 75 kW @ 800 rpm 100 lbft @ 3400 rpm
  • C16SEI
    98hp 73 kW @ 600 rpm 97 lbft @ 3400 rpm
  • E16SE
    100hp 75 kW @ 800 rpm 100 lbft @ 3400 rpm
  • L73
    74hp 55 kW @ 600 rpm 90 lbft @ 2800 rpm
  • G16SF
    92 hp (68 kW @ 600 rpm
  • Z16SE
    64 kW (86 hp) at 5400 rpm 98 lbft @ 2600 rpm
  • X16SZ
    52 kW (72 hp) at 5000 rpm at 2800 rpm
    16SV
    82 bhp@5400  (96 lbft) @ 2600 rpm

1.8 N18XFH

  • N18XFH
    106–108 hp at 5600 rpm 119–124 lbft @ 3200 rpm

For more information on Tuning your Family 1 engine please join us in our friendly forum where you can discuss tuning options in more detail with our Family 1 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 1 guides and tips are kept up to date.

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