Toyota UZ Tuning

"Guide to tuning the Toyota 1UZ-FE 2UZ-FE & 3UZ-FE engine!"

The Toyota UZ offer good returns when tuned and with the best upgrades like a remap, turbo upgrades and camshafts you will really enhance your driving enjoyment.

This pages aim is review and look at UZ tuning and report on the best upgrades.

This is a great engine and the fact it was used in the GT500 series shows the versatility and capability of the UZ engine block and design.

History, Power & Specs of the Engine

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

1UZ-FE 256 hp 260 lbft

The initial version of the 1UZ-FE engine had no variable valve timing and had intake and exhaust cam durations of 224° and 229°, respectively.

  • 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) By 1994, the intake valves' valve timing and lift were improved: valve overlap was increased to 9 degrees, intake duration was increased to 232 degrees, and exhaust duration was increased to 229 degrees.

  • 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

The VVT-i system was implemented on the 1UZ-FE engine commencing around 1997. Intake valve overlap ranged from -11 to 39 degrees, intake valve duration was 230 degrees, and exhaust valve duration was 229 degrees as a result.

Tuning the Toyota UZ and best UZ performance parts.

Best 1UZ-FE 2UZ-FE & 3UZ-FE modifications

Just because particular tuning parts appear in lots of UZ projects it doesn't mean you should fit it, so we'll ultimate tuning parts that will give your UZ the biggest power gain return for your cash.

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

Fast road cams typically increase bhp throughout the rpm range; you may lose a little low end bhp, but higher rpm power will be increased.

Race cams increase the higher rpm power band, but the car will not idle smoothly, and low end power almost usually suffers as a result.

On a daily driver, you should ideally strive to match your power band to your vehicle's usage.

You'll never have discovered a UZ. When driving in heavy traffic, that the race camshaft is a joy to live with. The low end idle will be quite bumpy and erratic, which you would not notice on a track when driving in the upper part of the rpm band, but on the road this is a big issue, and we've heard from many drivers who regret adding an aggressive competition cam profile to their engine.

Each engine responds better to more aggressive cam durations than others.

The map and fuel pump and injectors also have an effect on the bhp gains you'll get.

Longer valve durations can alter the bhp 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.

Please watch our video which covers the 5 principles of tuning your car. Be sure to keep up with our latest YouTube content and subscribe.

Best Engine Mods for your car

  1. Engine Tunes - engine tuning/remapping provides the most advantage in terms of cost savings,  aftermarket ECUs, and piggyback ECUs are all alternatives.
  2. Fast road cams are one of the most significant mechanical changes, but they must be installed by someone who knows what they're doing and they are not always easy to source but you might find a local firm to regrind a stock camshaft.
  3. Intake and Exhaust - Note that on their own these mods will NOT ADD POWER in most cases, but they can help enhance power after other mods by removing the restriction.
  4. Upgrades to turbochargers and superchargers - forced induction is the most efficient approach to increase air supply, allowing you to burn more fuel and make more power. It is one of the most costly upgrades but provides the best gains.
  5. Head work - The goals of porting and flowing the head are to get air flowing into the engine while removing flow restrictions and turbulence.

Typical stage 1 mods often include: Sports exhaust header/manifold, drilled & smoothed airbox, Fast road camshaft, Intake manifolds, Remaps/piggy back ECU, Panel air filters.

Typical stage 2 mods often include: Ported and polished head, high flow fuel injectors, induction kit, Fast road cam, fuel pump upgrades, Sports catalyst & performance exhaust.

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

Carefully think through your options and then acquire your upgrades and set yourself a power target to avoid wasting your time and money.

Mapping should help to release the full potential of all the parts you've fitted to your UZ.

(In some cases, as the factory ECU is locked flashing is not an option, so an aftermarket ECU is the route to take, and many of these will outperform factory ECU's but make sure it has knock protection and that you get it setup properly.)

It will usually give you around 30% more power on turbocharged vehicles and you can expect to see around 15% on NA (naturally aspirated) engines, but your mileage often depend much on the parts you've applied and the condition of your engine.

Feeding air and fuel into the UZ engine is vital to any car tuning task.

Intake manifolds flow the air from the air cleaner and allow it to be sucked into the engine and mixed with fuel.

Shape and flow rate of the Plenum can make a big change to fuel mixing and power on the UZ.

It's not uncommon that intake are improved through aftermarket parts, although some OEM provide reasonably good intake.

Larger UZ valves, carrying out port work and head flowing will also boost bhp and torque, and as an added benefit will raise potential for increasing the bhp and torque increase on other tuning mods.

UZ Turbo upgrades

Because NA (naturally aspirated) engines require a lot of effort when you add a turbo, we have a separate tutorial to assist you weigh the advantages and cons of taking this path on your UZ.

The more air that can enter an engine, the more fuel that can be burned, thus improving induction with a turbocharger upgrade results in enormous power gains.

When an engine is turbocharged, the parts produce more power, and turbocharged engines have more solid components.

Every engine has common points of failure, with some being overspecified and others barely able to handle stock power.

To handle the power, identify these restrictions and insert more robust crankshaft and pistons.

We see many tuners spending a lot of money on turbocharger upgrades on the UZ only to suffer the humiliation of seeing the motor throw a rod soon after it's finished.

Large turbochargers tend to suffer low end lag, and low capacity turbochargers spool up more quickly but do not have the peak rpm torque gains.

Over the last 20 years the range of turbo units is always developing and we now see variable vane turbo units, permitting the vane profile is altered according to speed to lower lag and increase top end power.

Twin scroll turbo units divert the exhaust flow into 2 channels and flow these at differently profiled vanes in the turbo charger. They also improve the scavenging effect of the engine.

You'll commonly see there is a limitation in the air flow sensor (AFM/MAF/MAP) on the UZ when a lot more air is being drawn into the engine.

Going up you'll find 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor sapped torque at a much lower level.

Adding a supercharger or additional turbo will make large torque gains, although harder to configure. We have this feature on twinchargers if you want to read more.

UZ Fuelling

When you increase the torque you will need to look at the fuel system.

More torque needs more fuel. Don't forget to over-specify your injectors flow rate.

As a rule of thumb add 20% to the flow rate when buying an injector, this accounts for injector deterioration and gives a little spare capacity should the engine require 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.

UZ Exhaust

You may need to increase your exhaust if your current exhaust is creating a restriction in flow.

On most factory exhausts you'll find the flow rate is good 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 can help equal out the flow of gases through the engine.

But if the exhaust pipe is too big, ie: it's over 2.5 inches bore, you will lose a lot of the exhaust flow rate and end up lacking power and torque.

Typically exhaust restrictions can be located the emissions filters installed, so adding a freer flowing sports alternative is the answer. This keeps the car road legal and will flow much better due to it's higher internal surface area and design, so has the added benefit of keeping your car road legal. The alternative decat should be considered an off road only mod, as removing a catalyst is illegal in most territories and regions for road registered cars.

Weak spots, Issues & problem areas on the UZ

The UZ engines are generally reliable and solid units, as long as you follow the manufacturer's service schedules, and use a good quality oil to ensure longevity. Few problems should happen as long as they are regularly serviced and maintained.

Carbon build up in the head, particularly around the valves which will sap power or create flat spots, this is a larger issue on direct injection engines but should be looked out for on all engines. We have tips on removing carbon buildup.

Some of our members have had issues with flat spots or glitches after applying mods and upgrades or tuning, this is not usually related to this engines design, so instead see our article on diagnosing flat spots and problems after tuning which should help you get the bottom of this issue.

Regular oil changes are vital on the UZ, especially when tuned, and will help extend the life and reliability of the engine.

If you would like to know more, or just get some friendly advice 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.

Please help us improve these tips by sending us your feedback in the comments box below.

We love to hear what our visitors have got up to and which upgrades work best for you on your car. Which helps us keep our guides and tips up to date helping others with their modified car projects. Your feedback and comments are used to keep this page up to date and help improve the accuracy of these UZ tuning guides which get regular updates and revisions.

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5 Responses to “UZ Tuning”

  1. Enno Cipa says:

    Hi,
    question: bigger valves I see a lot. But shouldn’t that also require a larger valve seat throat?? otherwise the larger valve would just shroud the opening more.

  2. TorqueCars says:

    Yes that is correct, you can’t just fit larger valves, much like you can’t fit larger tires without changing rims. Enlarging the valve seat is a given, but whilst you are at it, doing a 3 or 5 angle valve job helps make a little more power on most engines.

  3. Brandon Martin says:

    In addition to these great upgrades. Installing an Electric fan can dramatically improve throttle response and low end hp. It’s not adding power more like releasing power robbed by the fan clutch. Stage one modification. Also, electric fans now an days come with incredible air flow and can cool your engine better.

  4. Wes Jaegers says:

    I own a 2001 toyota land cruiser 4.7. I am using it as a weekend toy. High mileage, Time for a timing belt and exhaust gaskets. I was wondering if you have a specific set of cams as a suggestion for a drive to, have fun at, drive home setup? Thank you in advance.

  5. TorqueCars says:

    I’ve added cam durations to the article above for reference, it varied depending on the year. I would recommend increasing the cam by around 10 degrees (measured at.050 cam lift), any more and you’ll start to have a lumpy idle.

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