Modding uprating the Toyota AZ engine!

Modifying and improving: "AZ Modifications"

AZ Modifications Guide

How to modify and upgrade the Toyota AZ

"Comprehensive guide to performance parts and tuning the Toyota AZ engine!"

TorqueCars often are seeing threads requesting information on how to improve the AZ from people wanting to know what are the best AZ modifications. So let us look into Toyota AZ parts and outline the best modifications on this great engine and point out some problems along the way.

The Toyota AZ great bases for a tuning project and with the right tuning upgrades like remaps, turbo upgrades and camshafts you will certainly maximise your driving pleasure.

This pages aim is provide a guide to AZ tuning and summarise the greatest upgrades.

The optimum AZ mods on an engine are sensibly the ones that give the best gains for your money.

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

AZ induction kits

Improving air intake on the AZ

You need fuel and air for an engine to work. If there is a lack of fuel then it will run lean, if there is not enough air it runs rich sapping power . We'll pick up on fuelling later in this article but for now we shall look at air supply.

So Shoving more air and fuel into your AZ is the whole point to any car tuning job.

It is not unusual that there is a restriction in the air flow sensor MAF/MAP on the AZ when loads more air is being fed into the engine.

We note 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor limited performance at a much lower level.

Headers transmit the on the suck phase from the air cleaner and allow it to be drawn into the engine and mixed with fuel.

Structure and flow rate of the Intake can make a large change to fuel atomisation on the AZ.

Many mass produced engine intake manifold are crying out for motorsport parts, although some OEM provide reasonably good intake manifold.

Fitting big valve kits, getting AZ port enlargement and head flowing will also raise performance, and importantly will give you a greater performance increase on other tuning mods.

AZ performance cam tips.

Some AZ engines respond better to more or less aggressive cam durations so set your engine up on a rolling road.

The map and fuelling also will say much on the torque gains you'll make.

A longer valve duration 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.

Altering your AZ camshaft will make a dramatic difference to the engine bhp. Choosing a higher performance camshaft profile raises the bhp accordingly.

NB: Fast road cams commonly boost the bhp over the rev band, you might lose a little bottom end bhp but your top end will improve.

Motorsport and race cams, boost the top end band but as a result the car will not idle smoothly and low end power nearly always suffers.

In a road car you must carefully try to optimize your torque band to your usage of the car.

I'd be gobsmaked if you have ever thought a AZ Motorsport camshaft is a pleasure to live with when driving in heavy traffic.

Stage 1, 2 and 3 mods for the AZ

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 AZ parts:

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

Stage 2 AZ parts:

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

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

Stage 3 AZ parts:

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

The AZ units respond well to upgrades and we're happy to report there are increasing numbers of upgrades and tuning parts about.

ECU flashing will help to establish the full potential of all the parts you've done to your AZ.

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 the outcome usually depend much on the parts you've fitted and the condition of your engine.

Turbo modifications on the AZ

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 AZ.

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 your car is fitted with a turbocharger modifications are going to make more power and you'll see that turbocharged engines are made using harder and stronger components.

There are tuning limits for every engine, with some being extremely strong and some only just able to handle stock power

Research these restrictions and upgrade to better quality crank and pistons to cope with the power.

We've seen people spending a fortune on turbo upgrades on the AZ only to suffer the indignity of watching the engine throw a rod soon after it's finished.

Bigger upgraded turbo units commonly suffer low end lag, and low capacity turbo units spool up quickly but won't have the peak rpm engines power gains.

Thanks to new tech the choice of turbo chargers is always moving on and we now see variable vane turbo chargers, permitting the vane angle is altered according to speed to lower lag and increase top end power.

Twin scroll turbo chargers divert the exhaust gases into a couple of channels and feed these at differently angled vanes in the turbo charger. They also boost the scavenging effect of the engine.

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large torque gains, although more challenging to get working. We have this article on twincharging if you want to read more.

Tips about fuel supply on the AZ

Don't dismiss the need ramp up the fuel system when you are increasing the torque - it makes the car more thirsty. Don't forget to over specify your injector capacity.

As a rule of thumb add 15% when buying an injector, helps cope with injector deterioration and provides a little 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 AZ performance exhaust upgrades

You should look to increase your exhaust system with an upgraded one is if the existing exhaust is creating a flow problem.

On most factory exhausts you should find that the exhaust flow rate is good 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.

Please dont run with the widest exhaust you can buy this will slow the exhaust rate - the best exhausts 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.

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

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

Faults issues and things to look out for on the AZ

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

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