Tuning the Mazda MZR L5-VE

"Comprehensive guide to performance parts and tuning the Mazda MZR L5-VE engine!"

We often are getting emails requesting information on the best MZR L5-VE modifications. So let us look into Mazda MZR L5-VE modifications and outline the best modifications on this great engine and point out some potential pitfalls along the way.

The Mazda MZR L5-VE make awesome project engines and with carefully picked sports enhancements like a remap, turbo improvements and camshafts you will improve your driving opportunities.

Let us examine the options for your MZR L5-VE tuning and summarise the best upgrades.

Just because particular upgrades are are common on MZR L5-VE it doesn't mean it is good, we shall greatest upgrades that will give your MZR L5-VE the best power gain for you money.

Significant gains on the MZR L5-VE can be made from camshaft upgrades. Altering the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the power band and power output.

NB: Fast road camshafts normally boost the power across the rpm band, you might lose a little low down torque but higher rpm power will be higher.

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

A Race camshaft is not great driving around busy urban areas.

You should ideally match your bhp range to your typical driving style so for a road car stick with a fast road MZR L5-VE camshaft

Some MZR L5-VE engines respond better to different cam durations so set your engine up on a rolling road.

The map and fuelling 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.

MZR L5-VE Tuning Stages

Stage 1 MZR L5-VE modifications: Fast road camshaft, Sports exhaust manifold, Intake headers, Drilled & smoothed airbox, Remaps/piggy back ECU, Panel air filters.

Stage 2 MZR L5-VE modifications: Fast road cam, Sports catalyst & performance exhaust, Ported and polished head, fuel pump upgrades, induction kit, high flow fuel injectors.

Stage 3 MZR L5-VE modifications: Crank and Piston upgrades to alter compression, Competition cam, Internal engine upgrades (head flowing porting/bigger valves), Engine balancing & blueprinting, Adding or Upgrading forced induction (turbo/supercharger), Twin charging conversions.

Remaps allows a tuner to fully realize the full potential of all the parts you've done to your MZR L5-VE.

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 will depend much on the parts you've carried out and the condition of your engine.

Feeding more fuel and air into the MZR L5-VE engine is the aim to any performance tuning task.

Air Intake manifolds flow the air from the filter and allow it to be fed into the engine cylinders with fuel for the squish phase.

Design and flow characteristics of the Intake manifold can make a noticeable change to fuel atomisation and engine efficiency on the MZR L5-VE.

We often see air intake manifolds are ripe for performance upgrades, although a few makers provide fairly well optimized air intake manifolds.

Big valve conversions on the MZR L5-VE, doing a bit of port work and head flowing will also boost bhp, and significantly will raise potential for an improved bhp increase on other tuning mods.

Turbo upgrades for the MZR L5-VE

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 MZR L5-VE

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

When the engine is fitted with a turbo mods are going to net you a larger power gain and we find turbo engines already contain stronger components.

However most engines will have power limits

We recommend you find these limits and upgrade to higher quality components to handle the power.

We've seen guys spending a a stack of money on turbo charger upgrades on the MZR L5-VE only to suffer the humiliation of seeing the engine explode on it's first outing after it's been finished.

Larger capacity turbos tend to suffer a bottom end lag, and smaller turbos spool up much more quickly but won't have the top end bhp gains.

Thankfully the range of turbo units is always developing and we are seeing variable vane turbo units, where the vane angle is altered according to speed to lower lag and increase top end bhp and torque.

Twin scroll turbo units divert the exhaust flow into 2 channels and flow these at differently angled vanes in the turbo. They also help the scavenging effect of the engine.

It is common that there is a restriction in the air flow sensor AFM/MAP on the MZR L5-VE when a lot more air is being fed into the engine.

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

Adding a supercharger or additional turbo will make large power gains, although harder to install. We have this feature on twinchargers if you want to read more.

Uprating MZR L5-VE fuel injectors

You will need to ensure that the engine is not starved of fuel so will have to increase the fuelling when you start going beyond 20% of a performance increase.We strongly recommend you to over specify your injectors flow rate.

As a rule of thumb add 20% capacity when specifying an injector, this accounts for injector deterioration and gives you 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.

Best MZR L5-VE performance exhausts

You only need to to upgrade your exhaust if the existing exhaust is actually causing a restriction.

On most factory exhausts you should find that the 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.

Sports exhausts can help increase the flow of gases through the engine.

But if your exhaust is too large, ie: it's over 2.5 inches bore, you will lose a great deal of your flow rate and end up losing power and torque.

Typically exhaust restrictions are in the catalyst installed, so adding a freer flowing performance alternative will help avoid this restriction.

Problems and issues to look out for on the MZR L5-VE

The MZR L5-VE engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the MZR L5-VE, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your MZR L5-VE engine please join us in our friendly forum where you can discuss tuning options in more detail with our MZR L5-VE 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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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 Mazda. You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

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