Modifying and improving: "M15A Modifications"

M15A Modifications Guide

How to modify and upgrade the Suzuki M15A

"Comprehensive guide to performance tuning the Suzuki M15A engine!"

TorqueCars are always seeing threads requesting information on how to improve the M15A from people wanting to know what are the best tips on M15A power upgrades. So let us look into Suzuki M15A parts and outline the best upgrades on this great engine and point out some frequent tuning mistakes along the way.

Here we examine M15A tuning and summarise the ultimate modifications for your car. Suzuki M15A have loads of potential and with the best parts like ECU maps, turbo upgrades and camshafts you will noticeably maximise your driving enjoyment.

The optimum M15A tuning mods on an engine are in our opinion the ones that give the best gains for your money.

We won't be swayed by popular M15A tuning mods, they need to be cost effective.

M15A induction kits

Improving air intake on the M15A

You need air and fuel for an engine to work. If there is a lack of fuel then it will run lean, if there is insufficient air it runs rich sapping power and potentially damaging the engine. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So Forcing air and fuel into each cylinder is the main goal to any engine tuning job.

It is not unusual that there is a limit in the air flow sensor MAP/MAF/AFM on the M15A when loads more air is being pulled 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.

Air Intake manifolds carry the during the engines suck phase from the intake filter and allow it to be drawn into the engine and mixed with fuel.

The size of bore and shape and flow characteristics of the Headers can make a big effect on to fuel atomisation on the M15A.

We often see intake are ripe for performance upgrades, although some makers provide reasonably good intake.

Big valve conversions on the M15A, getting M15A port enlargement and head flowing will also improve power, & more importantly will make space for increasing the power increase on other parts.

M15A performance cam tips.

Different M15A engines respond better to extreme cam durations so view each engine as unique.

The ECU mapping and injectors and fuel pump also have a large bearing on the bhp gains you'll hit.

Altering 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.

Significant air intake, and exhaust improvements on the M15A can be made from cam upgrades. Changing 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 cams usually push up the bhp and torque across the rpm band, you may lose a little low end power but the high end rpm power will be lifted.

Motorsport and race cams, push up 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 camshaft won't do well if driving in heavy traffic.

You should ideally match your bhp range to your cars usage so for a daily driver stick with a shorter duration M15A camshaft

Stage 1, 2 and 3 mods for the M15A

Stage 1 M15A parts:

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

Stage 2 M15A parts:

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

Stage 3 M15A parts:

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

The M15A engines make great tuning projects and thankfully there is a lot of upgrades and performance parts out there.

Mapping will help unlock the full potential of all the upgrades you've done to your M15A.

Tuning tips and articles Engine tuning Transmission tuning Care care Intake & exhaust mods Improve handling Forums

You will typically expect to see gains of approximately 20-30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but your mileage may differs on the upgrades you've done and the condition of your engine.

Turbo modifications on the M15A

To get a turbo working on a NASP engine there is a lot involved, from lowering compression ratio to improved fuel supply and mapping, so we have found a great guide to helpavoid the common pitfalls or end up with an unfinished project because you were not told what you were getting into by doing this on the M15A.

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 an engine is turbo charged parts are simpler to install and most turbo charged engines are made with many forged and stronger components.

However engines will need better parts at higher power limits

Discover these limits and fit higher quality components to cope with the power.

There are many drivers spending a loads of money on turbocharger upgrades on the M15A only to watch the engine explode just after it's been completed.

Larger turbo units often suffer a bottom end lag, and little turbo units spool up really quickly but won't have the peak rpm torque gains.

In recent times the world of turbochargers is always evolving and we now see variable vane turbochargers, allowing the vane angle is altered according to speed to lower lag and increase top end bhp and torque.

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

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large bhp gains, although more difficult to install. We have this feature on twinchargers if you want to read more.

Tips about fuel supply on the M15A

You will need to ensure that the engine is not starved of fuel so must look at the fuelling when you start going beyond 20% of a torque hike. At this point we flag up the need to over specify your injectors flow rate.

The accepted safe increase is to add 15% when fitting an injector, this allows for injector deterioration and gives you some spare capacity should the engine require more fuel.

Don't forget that different fuel grades will usually require different settings, a high octane fuel will burn more efficiently than lower octane fuel for example. A car will trim fuel supply to keep within the ideal air fuel mix but at the extreme ends you may need to adjust your injector capacity, or the mapping or you'll get flat spots and potential lean or rich fuel issues..

Recommended M15A performance exhaust upgrades

You only need to to replace your exhaust system with an upgraded one is if your current exhaust is actually causing a restriction.

On most factory exhausts you'll see the flow rate is ok even on modest power gains, but on a serious tuning project with a big boost in power you will certainly need to get a better flowing exhaust.

Do not go with the widest exhaust you can get you'll slow the exhaust rate - the best for power gains are usually between one and a half to two and half inches. Your exhaust design, the bend angles and construction are what have more effect on flow rates than your pipe width to a certain extent. So the exhaust design is a big factor.

The usual suspects causing problems in your exhaust flow rate are in the filters installed, so adding a better flowing sports alternative will help avoid this restriction.

Decatting (NB:catalysts reduce harmful engine emissions) is illegal in most countries and regions.

Faults issues and things to look out for on the M15A

Like most engines an M15A, should have few issues if it gets properly serviced and looked after.

We cannot stress enough the need for oil changes with the correct grade of oil on the M15A, failure to do this will exacerbate engine wear, on a tuned M15A this is more important than ever and close attention should be paid to your maintenance schedule.

If you are interested in learning more or getting impartial tuning advice for your M15A why not pop over to the forums at TorqueCars where you can chat about M15A tuning options and read about others projects who may be planning to do similar modifications on their M15A.

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