Modding uprating the Mazda 13B engine!

Discover "13B Modifications"

How to modify and upgrade the Mazda 13B

"Comprehensive guide to performance parts and tuning the Mazda 13B engine!"

Forums like the one at TorqueCars often are getting emails requesting information on how to improve the 13B from people wanting to know what are the best tips for 13B upgrades. So let us look into Mazda 13B upgrades and outline the best upgrades on this great engine and point out some potential pitfalls along the way.

The Mazda 13B offer good returns when tuned and with a few sensible tuning mods like remapping, turbo upgrades you will substantially improve your driving enjoyment.

Here we examine the options for your 13B tuning and point out the optimum modifications for your car.

When talking about the best parts for your 13B engine, we are going to focus on the modifications that give the best power gain for you spend.

Rotary engines require more air and more fuel, as they are high revving they have much potential for top end improvment.

13B induction kits

Improving air intake on the 13B

You need air matched to fuel for an engine to work. If there is too little fuel then it will run lean, if there is not enough air it runs rich losing 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 Pulling more fuel and air into the 13B engine is the primary aim to any tuning job.

It is common that there's a limitation in the air flow sensor AFM/MAF on the 13B when loads more air is being drawn into the engine.

When tuning you may well find you need to get an air sensor or flow meter capable of upto 4 bars to cope with quite large power gains, whereas the OEM air sensor limited performance at a much lower level.

Air Intake manifolds carry the during the engines suck phase from the filter and allow it to be sucked into the engine cylinders with fuel for the squish phase.

The bore size, shape and rate of flow of the air Intake manifold and engine intake ports can make a big improvement to fuel atomisation on the 13B.

Pay attention to the rotors too, and make sure these are machined to tight tolerances and fully balanced.

Many mass produced engine air intake manifolds are improved through performance upgrades, although a few manufacturers provide fairly well optimized air intake manifolds.

Larger 13B intake valves, and flowing them will also increase torque, the fantastic side effect is it will give you a greater torque and power increase on other tuning parts.

The map and injectors and fuel pump also will say much on the power gains you'll make.

You should ideally optimize your bhp range to your preferences so for a car used daily stick with a mild fast road 13B camshaft

Stage 1, 2 and 3 mods for the 13B

Before we break the best tuning upgrades down into stages of tune, let's list the most effective tuning upgrades for you.

  1. Suspension Upgrades - always improve your cars handling
  2. Brake Upgrades - Even before adding power improve those brakes
  3. Intake - make sure the intake is not restricted, use filters and intake upgrades to improve this
  4. Exhaust - as with 3 ensure there is not restriction in the exhaust, cats are the usual bottleneck
  5. Tunes - remapping, piggyback ECU's and aftermarket ECU's can all make decent gains
  6. Fuelling - when you've increased power you'll need to match this with more fuel
  7. Turbo upgrades - Improving the intake with a large turbo and better flowing intercooler will be the biggest power gain you'll see (but one of the most complex).

This video guide to tuning cars is a great starting point to work from in your project.

Stage 1 13B parts:

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

Stage 2 13B parts:

Engine porting, fuel pump upgrades, high flow fuel injectors, Fast road cam, Sports catalyst & performance exhaust, induction kit.

Stage 3 13B parts:

Rotor machining, honing and balancing, Internal engine upgrades (head flowing porting/bigger valves), Engine balancing & blueprinting, Twin charging conversions, Adding or Upgrading forced induction (turbo/supercharger).

Tuning tips and articles Engine tuning Transmission tuning Care care Intake & exhaust mods Improve handling Forums
The 13B engines make great tuning projects and we're finding that there are increasing numbers of parts and tuning parts around.

Remapping will help to establish the full potential of all the tuning parts you've done to your 13B.

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 results may differs on the tuning parts you've fitted and the condition of your engine.

Turbo modifications on the 13B

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 13B.

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.

If a car has a turbo already fitted parts are going to net you a larger power gain and we find turbo engines are built with more solid components.

However you'll find engines will have power limits

See where you'll find these limits and fit more solid crank and pistons to handle the power.

We've seen drivers spending a lots of money on turbo upgrades on the 13B only to watch the engine block go up in smoke on it's first outing after it's been completed.

Large capacity turbochargers tend to experience a bottom end lag, and small turbochargers spool up really quickly but don't have the high rpm bhp gains.

In recent times the range of turbo units is always increasing and we now see variable vane turbo units, permitting 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 gases into a couple of channels and direct these at differently designed vanes in the turbo charger. They also help 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 challenging to setup. We have this feature on twinchargers if you want to read more.

Tips about fuel supply on the 13B

You will need to ensure that the engine is not starved of fuel so need to look at the fuelling when you start extending past 20% of a bhp and torque hike. We would recommend you to over specify your flow rate on the injectors.

The rule of thumb is to add another 20% when specifying an injector, this takes into account injector deterioration and affords a bit of spare capacity should the engine need 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 13B performance exhaust upgrades

You only need to to upgrade your exhaust system with an upgraded one is if the current exhaust is creating a flow problem.

On most factory exhausts you'll find the flow rate is still 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.

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

But if your exhaust is too large, ie: over two and a half inches diameter, you will lose a great deal of the flow rate and end up sapping power and torque.

Usual exhaust restrictions are traced to the catalyst and filters installed, so adding a freer flowing high performance alternative will help avoid this restriction.

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

Faults issues and things to look out for on the 13B

Like most engines an 13B, 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 13B, failure to do this will exacerbate engine wear, on a tuned 13B 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 13B why not pop over to the forums at TorqueCars where you can chat about 13B tuning options and read about others projects who may be planning to do similar modifications on their 13B.

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

We want to know your experiences with parts on your 13B, it helps us improve our tips and keeps us current so please use the comments box to drop a tip.

If you liked this page please share it with your friends, drop a link to it in your favourite forum or use the bookmarking options to save it to your social media profile.

Check out TorqueCars new YouTube channel, and see their awesome new content...


Please use our forums if you wish to ask a tuning question, and please note we do not sell parts or services, we are just an online magazine.

Help us improve, leave a suggestion or tip

Your Constructive comments on this article