Scion tC Tuning

"Tuning guide to the greatest Scion tC modifications."

We were asked questions for more information on tuning and building a modified tC and particularly which turbo upgrades work best, so we've put together this how to guide which covers our go to enhancements for this engine and what we feel are the optimum value enhancements you can do.

The Toyota Scion tC is a compact sports coupe that was manufactured and sold by Toyota under its youth-oriented Scion brand from 2004 to 2016. It was designed to appeal to young, urban, and trend-conscious drivers and offered features such as sporty styling, a spacious and versatile interior, and a fun-to-drive character. The tC was discontinued in 2016 as part of Toyota's discontinuation of the Scion brand.

The tC is a awesome project car to take up your weekends. Take your time and research tC tuning to avoid making the usual disastrous errors we typically hear people complain about.

Tuning tips and articles

Engine tuning Transmission tuning Care care Intake & exhaust mods Improve handling Forums

Scion tC Handling/Suspension upgrades

Handling modifications are high on most peoples lists for the tC.

We found that most tC factory suspension setups need tweaking, a few degrees of toe (set some toe out to improve cornering or use toe in for better stability) and you only need around 1-1.7 degrees, and some negative camber will substantially enhance your cornering and handling.

There are several upgrades that can be made to the suspension on a Scion tC to improve its handling and performance. Some popular upgrades include:

  1. Lowering Springs: Lowering the car's center of gravity by installing lowering springs can improve handling and stability.
  2. Shock Absorbers: Upgrading to high-performance shock absorbers can improve ride quality and handling.
  3. Strut Bars: Installing strut bars can stiffen the chassis and reduce body roll, improving handling and stability.
  4. Sway Bars: Upgrading the sway bars can improve handling and reduce body roll during cornering.
  5. Wheel Spacers: Installing wheel spacers can improve the car's stability and handling by providing a wider track. We do not recommend these as they can impair the cars safety if not fitted correctly and it makes more sense to fit properly apportioned alloy wheels to provide a wider track.
  6. Coilovers: Installing coilovers can provide adjustable ride height and stiffness, allowing for greater customization and improved handling.
We would go to a maximum drop of 24mm - 38 mm. on most models. You risk rubbing on the arches if you go lower than this.

Brake Upgrades

Fitting better brake discs and better high friction brake pads will make for dramatically improved stopping. (They will brake effectively over longer periods during heavy use than stock brakes will. Note that your Scion's grip has more of a bearing on the cars ability to stop especially in emergency stop situations).

Please note that some performance friction pads will be noisy and will need to be hot before they bit.

In every day driving the brakes are only used rarely so will not be effective so source pads which have a low working temperature.

Our aim in tC engine tuning should be to increase peak power and Torque at the top end.

Enjoy your tC to the max with our great modification tips - do the right mods in the right order.

Smaller engines do not provide much of a return in terms of power so start with a bigger engine. Engine swaps are a good option if you have a small engine size.

Engine Tuning.

These are the modified kits are usually carried out by our members, decide how far you want to push your car before you get going.

Getting the correct grade of motorsport upgrade kits for your planned usage of the car is essential. Stage 3 (competition) mods just don't work well on the road making the car difficult to drive.

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 Scion tC

  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.

Scion tC Tuning Stages

Typical stage 1 mods often include: Suspension upgrade (drop 24mm - 38 mm.), Alloy wheels, Lighter flywheel, Sports exhaust, Engine Tunes/Remapping, Panel air filter.

Typical stage 2 mods often include: high flow fuel injector, Power/Sport clutch, fuel pump upgrades, Fast road cam, Ported and polished head.

Typical stage 3 mods often include: Sports gearbox, Adding or upgrading forced induction (turbo/supercharger), Internal engine upgrades (pistons/head/valves), Competition cam, Engine balancing.

Your aim when modding your car should be a wide torque range. You want to avoid sending all the power to be at the top end of the rev range unless you are creating a motor sport car.

In this article we shall give a little insight into the world to the best mods for your car, but we'd encourage you to spend some time on the site looking into the details of each type of performance part.Fast road cams offer one of the biggest performance gains for your money as far as a bolt on performance modifications goes on a NA (naturally aspirated) engine.

It improves the intake and exhaust durations and increases the power if done right. Ideally you'd add other mods and finish up with a reflashed ECU. We'd also caution you not to go with a competition cam as this upsets the engines idling and general town driving characteristics.

Don't forget to increase the fuelling when you are increasing the power - it makes the car more thirsty.

Frequently power losses, flat spots and erratic idling after motorsport modifications are done can usually be traced to fuelling or timing issues. To get sufficient fuel you may need to uprate the injectors on your engine.

Uprate the fuel pump to cope with the extra fuel requirements of your tuned tC's uprated injectors.

Intake and Exhaust Tuning.

The next area for modification is the intake and exhaust.  Contrary to popular belief there is generally very little if any power gain got by fitting an induction kit, they only help and are recommended after you raise the engines power to the point where the standard air intake box cannot cope!

Derestricting the airflow into the engine is a primary goal of performance tuning. To facilitate this you should invest in a freer flowing air filter especially if you find that the car is running lean. Induction kits can sound fun but due to the warm air in the engine bay carrying less oxygen, they will not add noticeable power and more often than not rob you of power.

Sports exhausts can help equal out the flow of gases through the engine. But if your exhaust is too big, ie: over 3 inches bore, you will lose much of the exhaust flow rate and end up sapping power and torque.

Head work including a gas flow and 3 or 4angle valve job will really help to release the potential of the engine. In nearly all cases of tC tuning your clutch will start to suffer and this should be improved - read our tips on clutches for more information. The best mods we would do for your tC are Remapping or piggy back ecu, fast road cam and air intake and exhaust.

NA (naturally aspirated) engines do not achieve big power gains if you tune/remap them, unless you have done extensive modifications. With turbocharged engines this is another story. A tuned/remapped turbo will give phenomenal power gains and fully release the potential power of the engine.

We've also come across some owners playing with twincharged conversions and making some very high power gains.

Supercharger or Turbo Conversion?

Despite the large cost involved adding forced induction to a NA (naturally aspirated) engine will give large power gains. Superchargers are often easier to add than a turbo. Turbos increase power in increasing proportion to increasing engine speed and this can make mapping difficult.

Fitting a turbo kit to your tC is quite a big and complex project, which is beyond the scope of this article but we've got articles on adding turbos to NA engines which should point you in the right direction and flag up the potential issues and problems you will typically encounter.

It is generally speaking simpler to map a supercharger because the boost is correlating to engine speed on a linear curve making this form of forced induction upgrade the preferred option by many. Decreasing the engines compression ratio, and fitting stronger components is recommended as this will allow you to add forced induction, and minimize the risk of detonation. Water injection and switching fuel type and grade to something like E85 or premium gas may also help prevent detonation or preignition.

Alloy wheel upgrades.

Alloy wheels will help the brake cooling and are generally lighter than the steel ones. Further improvements can be made to your cars handling with the addition of directional tread pattern tire. It is worth noting that although they can look cool on the tC big alloys will actually decrease your performance. The larger you go the lower your acceleration will be - this to the change in your effective final drive ratio.

Although some people have fitted larger wheels without problems we would restrict ourselves to a 16 inch rim size as the maximum.

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

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