All you need to know about "NZ Modifications"

How to modify and upgrade the Toyota NZ

"Comprehensive guide to tuning the Toyota NZ engine!"

Our friends at TorqueCars are regularly seeing threads requesting info on how to improve the NZ from people wanting to know what are the optimum NZ modifications. So let us look into Toyota NZ tuning mods and outline the best upgrades on this great engine and point out some problems along the way.

Car Tuning Tips will detail the best approach to NZ tuning and report on the best mods that work. Toyota NZ are awesome to work on and with the optimum performance enhancements like remaps, turbo kits and camshafts you will substantially enhance your driving experience.

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

Improving air intake on the NZ

You need air and fuel for an engine to work. If there is little supply of fuel then it will run lean, if there is insufficient air it runs rich resulting in lost power which risks damage to the NZ. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So it's important to any performance tuning project to shove more air and fuel into each cylinder but this has a knock on effect with the air flow sensor.

It is common that there's a restriction in the air flow sensor MAP/MAF/AFM on the NZ when considerably more air is being sucked into the engine.

You'll see that 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting torque at a much lower level.

Engines intake headers transmit the on the suck phase from the air cleaner and allow it to be pulled into the engine cylinders with fuel for the squish phase.

The size of bore and shape and rate of flow of the Intake can make a large effect on to fuel atomisation and engine efficiency on the NZ.

I usually find intake manifold are needing motorsport parts, although some car makers provide reasonably well designed intake manifold.

Adding a NZ larger valve kit, carrying out 3 or 5 angle valve jobs and porting and head flowing will also improve bhp and torque, & importantly will raise potential for a better bhp and torque increase on other tuning parts.

NZ performance cam tips.

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

The map and fuelling also have an effect on the torque gains you'll make.

Extending exhaust or intake 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.

The camshaft profile plays a big part in the engines power output so camshaft upgrades make quite a large difference. The intake & exhaust durations will alter depending on the chosen camshaft profile, so large bhp gains are on offer for camshaft upgrades.

NB: Fast road camshafts commonly push up the bhp over the rpm band, you could drop a little low end bhp but your higher rpm power will be higher.

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

A Race cam will just annoy you whilst driving in heavy traffic.

You should ideally optimize your power band to your driving style so for a typical daily driver stick with a shorter duration NZ cam

Stage 1, 2 and 3 mods for the NZ

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 NZ parts:

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

Stage 2 NZ parts:

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

Stage 3 NZ parts:

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

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

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 rely on the parts you've fitted and the condition of your engine.

Turbo modifications on the NZ

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 NZ.

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

When an engine is turbo charged parts are simpler to install and most turbo engines already contain strengthened components.

However you'll find engines have weakspots

It is important to find these restrictions and fit more solid crank and pistons to survive the power.

We've seen car owners spending a a stack of money on turbo upgrades on the NZ only to suffer the humiliation of seeing the motor catastrophically fail on it's first outing after it's been finished.

Big turbochargers often experience low end lag, and smaller turbochargers spool up quickly but won't have the high rpm torque gains.

We are pleased that the market of turbo units is always improving and we are seeing variable vane turbo units, where the vane angle is altered according to speed to lower lag and increase top end power.

Twin scroll turbo units divert the exhaust flow into two channels and flow these at differently designed vanes in the turbocharger. 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 performance gains, although more difficult to get working. We have this in depth look at twinchargers if you want to read more.

Tips about fuel supply on the NZ

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 performance hike. We strongly recommend you to be generous with your injector capacity.

The accepted safe increase is to add 15% to the flow rate when fitting an injector, this allows for injector deterioration and gives a bit of 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 NZ performance exhaust upgrades

We'd only recommend you look to uprate your exhaust system with an upgraded one is if the existing 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 on a serious tuning project with a big boost in power you will certainly need to get a better flowing exhaust.

Sports exhausts will certainly help air flow from the engine but do not go too big or you may end up will reduce the flow rate. Stick to one and a half to two and half inches for best results.

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

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

Faults issues and things to look out for on the NZ

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

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 tuning parts on your NZ, it helps us improve our tips and keeps us current so please use the comments box to drop a tip.

This entry was posted under Makes and Models. Tags: engine, toyota
You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

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...