Tuning the Suzuki M13A

"Comprehensive guide to performance parts and tuning the Suzuki M13A engine!"

We are regularly seeing threads asking how to improve the M13A from people wanting to know what are the best tips for M13A power upgrades. So let us look into Suzuki M13A tuning mods and outline the best mods that work on this great engine and point out some frequent tuning mistakes along the way.

The Suzuki M13A are good project engines and with the best parts like ECU maps, turbo upgrades and camshafts you will certainly maximise your driving opportunities.

Let us detail the best approach to M13A tuning and summarise the ultimate mods that work.

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When talking about the ultimate parts for your M13A engine, we are going to concentrate on the ones that give the biggest return for your cash.

Significant gains on the M13A can be made from cam upgrades. Altering the cam profile alters the intake and exhaust durations on the engine and can dramatically change the engines power and power output.

NB: Fast road camshafts normally bump the bhp and torque across the rpm range, you might lose a little bottom end bhp but your high end rpm power will improve.

Race camshafts, 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 and race cam is not great in heavy traffic.

You should ideally optimize your bhp range to your cars usage so for a typical daily driver stick with a fast road M13A cam

Different M13A engines respond better to more aggressive cam durations than others.

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

Extending exhaust or intake 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.

M13A Best Tuning Mods & Upgrades

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Guide to the best M13A 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.

M13A Tuning Stages

Stage 1 M13A modifications: Fast road camshaft, Drilled & smoothed airbox, Panel air filters, Intake headers, Remaps/piggy back ECU, Sports exhaust manifold.

Stage 2 M13A modifications: Ported and polished head, Fast road cam, fuel pump upgrades, high flow fuel injectors, Sports catalyst & performance exhaust, induction kit.

Stage 3 M13A modifications: Twin charging conversions, Internal engine upgrades (head flowing porting/bigger valves), Engine balancing & blueprinting, Competition cam, Crank and Piston upgrades to alter compression, Adding or Upgrading forced induction (turbo/supercharger).

The M13A engines are fantastic to work on and we're finding that there is a growing number of upgrades and tuning parts about.

Mapping will help to establish the full potential of all the parts you've done to your M13A.

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 parts you've done and the condition of your engine.

Shoving more air and fuel into the M13A engine is the aim of any engine tuning project.

Intake manifold flow the air during the suck phase from the filter and allow it to be pulled into the engine cylinders with fuel for the squish phase.

The shape and rate of flow of the Intake can make a big change to fuel mixing and power on the M13A.

Most intake manifold are ripe for a performance upgrade, although a few car makers provide decently flowing intake manifold.

Larger M13A valves, doing some 3 or 5 angle valve jobs and porting and head flowing will also raise bhp and torque, & importantly will raise the potential for a better bhp and torque increase on other tuning parts.

Turbo upgrades for the M13A

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 M13A

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.

When a car has a turbocharger parts are going to net you a larger power gain and most turbocharged engines use stronger components.

However you'll find engines will have power limits

See where you'll find these limits and fit better quality crank and pistons to survive the power.

We've seen guys spending a loads of money on turbo upgrades on the M13A only to watch the motor catastrophically fail on its first outing after it's finished.

Large turbos often experience low end lag, and small turbos spool up more quickly but do not have the high rpm torque gains.

Thanks to new tech the world of turbo units is always evolving and we commonly find variable vane turbo units, where the vane profile is altered according to speed to lower lag and increase top end bhp.

Twin scroll turbo units divert the exhaust flow into two channels and direct these at differently angled vanes in the turbo charger. They also increase the scavenging effect of the engine.

You'll commonly see there is a limit in the air flow sensor MAP/MAF/AFM on the M13A when considerably more air is being sucked into the engine.

We note 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 gains, although more difficult to get working. We have this in depth look at twinchargers if you want to read more.

Uprating M13A fuel injectors

When you improve the bhp you will need to increase the fuel delivery.

More bhp needs more fuel. It makes sense to over specify your injectors flow rate.

The accepted safe increase is to add 20% when buying an injector, helps cope with injector deterioration and affords 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.

Best M13A performance exhausts

You may need to improve your exhaust if your current exhaust is actually causing a restriction.

On most factory exhausts you should find that your 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.

Do not go with the biggest exhaust you can find this will slow the exhaust rate - the best exhausts 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 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 better flowing performance alternative will help avoid this restriction.

Problems and issues to look out for on the M13A

The M13A engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the M13A, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your M13A engine please join us in our friendly forum where you can discuss tuning options in more detail with our M13A owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

We need your help to complete and improve this page, so do give us your feedback in the comments box below.

We really like hearing from our readers, and hearing about which 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 M13A guides and tips are kept up to date.

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