Modding tuning and best performance upgrades on the Toyota 3ZR engine!

Modifying and improving: "3ZR Modifications"

3ZR Modifications Guide

How to modify and upgrade the Toyota 3ZR

"Comprehensive guide to performance parts and tuning the Toyota 3ZR engine!"

Forums like the one at TorqueCars are regularly seeing threads requesting information on how to improve the 3ZR from people wanting to know what are the best 3ZR modifications. So let us look into Toyota 3ZR parts and outline the best mods that work on this great engine and point out some problems along the way.

Now we will outline options for your 3ZR tuning and highlight the ultimate upgrades. Toyota 3ZR provide a fun base for your project and with a few sensible performance tuning mods like remapping, turbo kits and camshafts you will greatly maximize your driving opportunities.

The ultimate 3ZR parts on an engine are typically the ones that give the best gains for your money.

We won't be swayed by popular 3ZR parts, they need to be cost effective.

3ZR induction kits

Improving air intake on the 3ZR

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 . We'll pick up on fuelling later in this article but for now we shall look at air supply.

So the goal to any engine tuning job to force more air into the 3ZR engine but this has a knock on effect with the air flow sensor.

You'll commonly see there's a restriction in the air flow sensor AFM/MAF on the 3ZR when loads more air is being drawn 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.

Intake manifolds flow the air during the suck phase from the intake filter and allow it to be pulled into the engine cylinders.

Shape and flow rate of the Headers can make a substantial effect on to fuel mixing and power on the 3ZR.

I usually find intake manifold are begging for aftermarket tuning parts, although a few car makers provide fairly well optimized intake manifold.

Big valve conversions on the 3ZR, carrying out port matching and head flowing will also raise torque, & importantly will raise potential for a better torque increase on other modifications.

3ZR performance cam tips.

Different 3ZR engines respond better to more aggressive cam durations so set your engine up on a rolling road.

The ECU mapping and fuelling also will make differences on the torque gains you'll get.

Longer 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.

Altering your 3ZR cam will make a dramatic difference to the engine bhp. Choosing a higher performance cam profile raises the bhp accordingly.

NB: Fast road camshafts usually raise the bhp and torque through the rpm range, you may sacrifice a little bottom end power but top end will be better.

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

For a road car you need to match your power band to your driving style.

I'd be gobsmaked if you have found a 3ZR Motorsport camshaft is a pleasure to live with when driving around busy urban areas.

Stage 1, 2 and 3 mods for the 3ZR

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 3ZR parts:

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

Stage 2 3ZR parts:

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

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

Stage 3 3ZR parts:

Competition cam, Twin charging conversions, 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 3ZR power plant make great tuning projects and we're happy to report there are quite a few choices of modifications and tuning parts around.

ECU flashing helps release the full potential of all the mods you've done to your 3ZR.

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 end result often depend much on the mods you've applied and the condition of your engine.

Turbo modifications on the 3ZR

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 3ZR.

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

When the engine is turbo charged modifications are simpler to install and turbo engines already contain strengthened components.

However every engines have weakspots

It is important to find these restrictions and fit better quality components to survive the power.

We've seen guys spending a loads of money on turbocharger upgrades on the 3ZR only to suffer the humiliation of seeing the car catastrophically fail when it's been enthusiastically driven.

Larger turbos commonly experience a bottom end lag, and smaller turbos spool up quickly but do not have the peak end power band gains.

In the last 10 years the choice of turbochargers is always moving on and we commonly find variable vane turbochargers, permitting the vane profile is altered according to speed to lower lag and increase top end bhp and torque.

Twin scroll turbochargers divert the exhaust gases into a couple of channels and direct these at differently angled 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 bhp gains, although more challenging to get working. We have this guide to twinchargers if you want to read more.

Tips about fuel supply on the 3ZR

When you increase the performance you will need to pay attention to to the fuel system.

More performance needs more fuel. It makes sense to be generous with your flow rate on the injectors.

The rule of thumb is to add 15% when buying an injector, this accounts for injector deterioration and affords 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 3ZR performance exhaust upgrades

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

On most factory exhausts you'll see the exhaust 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.

Please dont run with the largest exhaust you can buy you'll reduce the exhaust flow 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 can be traced to the filters installed, so adding a faster flowing race 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 3ZR

Like most engines an 3ZR, 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 3ZR, failure to do this will exacerbate engine wear, on a tuned 3ZR 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 3ZR why not pop over to the forums at TorqueCars where you can chat about 3ZR tuning options and read about others projects who may be planning to do similar modifications on their 3ZR.

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