Tuning the Toyota UZ

"Comprehensive guide to performance tuning the Toyota UZ engine!"

The Toyota UZ offer good returns when tuned and with the best motorsport tuning mods like remapping, turbo upgrades and camshafts you will increase your driving opportunities.

Our aim here is to review and look at UZ tuning and provide tips on the optimum mods that work.

Just because particular modifications are appear in lots of UZ projects it doesn't mean it is good, we will concentrate) on the top modifications that will give your UZ the biggest power gain return for your cash.

Significant gains on the UZ can be made from camshaft upgrades. Altering the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the torque and power output.

NB: Fast road camshafts tend to raise the performance through the rpm band, you may lose a little low down bhp but the top end will be higher.

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

A Race cam won't do well if driving around busy urban areas.

You should ideally optimize your torque band to your cars usage so for a typical daily driver stick with a mild fast road UZ cam

Each engine responds better to less aggressive camshaft durations check your engine on a rolling road.

The ecu map and fuel pump and injectors also will say much on the torque gains you'll hit.

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.

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Guide to the best UZ tuning mods & Upgrades

  1. ECU Map Tuning & Remaps

    Some cars may require a piggyback ECU's or aftermarket ECU's to change the OEM map, but remapping is the most vital step of your tuning project to fully maximise your mods. Expect 10-20% on NASP engines and 30-40% on turbocharged units.

  2. Strengthen Your Engine

    Tuned cars will show up weaknesses, typically in the turbochargers, clutch and internal engine components. Whilst most engines can cope with mild tuning mods, TorqueCars recommend that you upgrade the internal components before these weak spots manifest themselves.

  3. Mods that Remove a Restriction

    A restricted intake or exhaust will have an impact on your performance, so use a better flowing air filter/induction kit and better flowing exhaust (sports cats where legal are a good option) whenever your tuning creates a flow restriction. Turbo engines also benefit from intercooler upgrades as these resist heat soak for longer periods of time.

  4. Mods that Improve Fuelling

    Every tuning project will aim to increase the air supply, but fuel supply is just as vital and will need to match the air the engine can utilise,  a fuel pump and injector upgrade are usual mods, but also in many cases the fuel regulator will need improvement.

  5. Mods to Provide better Airflow

    Increasing the air supply is just as essential as improving fuelling, we suggest you look at head mods (flowing and porting, 5 angle valve jobs), fit bigger valves, fast road cams and forced induction upgrades (adding a better flowing turbo) to improve air intake.

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

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

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

The UZ power trains are fantastic to work on and we see that there is a lot of mods and performance parts out there.

A remap allows a tuner to to establish the full potential of all the upgrades you've fitted to your UZ.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but power output usually rely on the upgrades you've carried out and the condition of your engine.

Feeding more air into your UZ is the aim to any car tuning task.

The intake plenum take the air during the suck phase from the intake filter and allow it to be drawn into the engine cylinders.

The bore size, shape and flow characteristics of the Headers can make a large change to fuel delivery on the UZ.

Commonly we find the air intake manifolds are begging for a performance upgrade, although a few OEM provide well optimised air intake manifolds.

Increasing the UZ valve size, doing some port matching and head flowing will also raise torque, and importantly will permit increasing the torque increase on other upgrades.

Turbo upgrades

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 UZ

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

If your motor is turbo charged mods are relatively easy and most turbo engines already contain better components.

However every engines have limits

Discover these restrictions and fit better pistons and crank to survive the power.

There are many people spending a a stack of money on turbocharger upgrades on the UZ only to experience the car explode on it's first outing after it's been enthusiastically driven.

Larger capacity turbo chargers tend to suffer a bottom end lag, and smaller turbo chargers spool up more quickly but do not have the top end power band gains.

We are pleased that the world of turbochargers is always increasing and we are seeing variable vane turbochargers, where the vane profile is altered according to speed to lower lag and increase top end bhp.

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

It is not unusual that there is a limit in the air flow sensor MAP/MAF/AFM on the UZ when considerably more air is being drawn into the engine.

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

Adding a supercharger or additional turbo will make large bhp and torque gains, although more difficult to setup. We have this article covering twinchargers if you want to read more.

Fuelling upgrades and mods

You will need to ensure that the engine is not starved of fuel so must pay attention to the fuelling when you start exceeding 20% of a torque increase.Most tuners we speak with say to over specify your injectors flow rate.

The rule of thumb is to add 20% when fitting an injector, helps cope with injector deterioration and allows some spare capacity should the engine need 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.

Exhaust upgrades and mods

You only need to to upgrade your exhaust if the existing exhaust is creating a flow problem.

On most factory exhausts you'll find the exhaust flow rate is fine 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 equal out the flow of gases through the engine.

But if the exhaust pipe is too large, ie: over 2.5 inches bore, you will lose a great deal of the exhaust flow rate and end up lacking power and torque.

Typically exhaust restrictions come around the catalysts installed, so adding a freer flowing high performance alternative will help avoid this restriction.

Weak spots, Issues & common problem areas on the UZ

The UZ engines, if regularly serviced and maintained, are generally very reliable and have few issues.

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

History of the Engine

It had a quad cam V8 setup and came in 3 revisions over the years.

1UZ-FE 256 hp 260 lbft

  • 1989–2000 Lexus LS 400/Toyota Celsior
  • 1989–2002 Toyota Crown/Toyota Crown Majesta
  • 1989–2004 Toyota HiAce HiMedic Ambulance (Japan only)
  • 1991–2000 Lexus SC 400/Toyota Soarer
  • 1992–2000 Lexus GS 400/Toyota Aristo

2UZ-FE 271 hp  315 lbft

(Came with VVT-i and drive by wire throttle in later years)

  • 2002–2009 Lexus GX 470
  • 1998–2007 Lexus LX 470
  • 1998–2011 Toyota Land Cruiser
  • 2002–2009 Toyota 4Runner
  • 1999–2009 Toyota Tundra
  • 2000–2009 Toyota Sequoia

3UZ-FE 290 to 300 hp 325 lbft

This engine was also used on the GT500 supra and Lexus GT500 motorsport version, in a higher state of tune with a 4.4L displacement.

  • Lexus LS 430
  • Lexus GS 430
  • Lexus SC 430/Toyota Soarer
  • Toyota Crown Majesta

For more information on Tuning your UZ engine please join us in our friendly forum where you can discuss tuning options in more detail with our UZ owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

We need your help improving this article, so please send us your feedback in the comments box below and pass on any tips, points or facts we have wrong or have not covered.

We really like hearing from our readers, and hearing about which upgrades were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our UZ guides and tips are kept up to date.

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