Seat Mii Tuning

"Thanks for reading my Seat Mii tuning guide."

Little cars like the Mii are fun to drive, and because they are lightweight, they make great project cars.

Even minor mods can make a difference to the performance and handling of the Mii.

The Mii is a really  good car tuning project to have. If you do your homework then you can create an awesome Mii but don't be fooled there are lots of high performance upgrades out there that will simply not suit it read our unbiased guides first.

Tuning tips and articles

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

Turning our attention to the engine we need to get a bit more power out of the top end.

Enjoy your Mii to the max with our hot performance tuning guides - 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 mods.

Typically these tuning upgrades are usually fitted by our members, decide how far you want to push your car before you get going.

Getting the correct grade of modified upgrade kits for your planned usage of the car is vital. Stage 3 competition upgrades just won't work well on the road making the car difficult to drive.

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Guide to the Best Tuning Mods & Upgrades

  1. Mods that Remove a Restriction

    If the intake or exhaust are restricted in any way this will have an impact on your cars performance, so use an induction kit/filter upgrade and better flowing exhaust whenever your tuning creates a flow restriction.

  2. Mods that Improve Handling

    Braking, Suspension and general alignment of the suspension components is vital for any tuning project even before you start increasing power.

  3. Fit Stronger Parts

    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.

  4. ECU Tunes & Remapping

    While some cars can be easily remapped, others may require piggyback ECU's or aftermarket ECU's but this is the most vital step of your tuning project as it fully releases the power from all of your mods and upgrades. Expect 10-20% on NASP engines and 30-40% on turbocharged units.

  5. More Power Needs More Fuel & Air

    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. Fuel to Air ratio is vital so upgrade the fuel pump & injectors. Also you can look to perform head mods (flowing and porting), bigger valves, fast road cams and forced induction upgrades to improve fuel.

Stages of Tune

Stage 1 mods: Remap, Suspension upgrade (drop 30-40mm), Alloy wheels, Sports exhaust, Panel air filter, Lighter flywheel.

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

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

You really need to keep as much low end power as you can and aim for a wide power band rather than a narrow top end power spike.

The point of our pointers is to give a little insight into the world of tuning upgrades and point you in the right direction, our forum is best place to go if you need more detailed advice and tips on your car tuning project, the best tuning kits and all aspects of modding cars.One of the most cost effective mechanical motorsport mods you can do on your NASP engine is to fit a fast road camshaft .

The exhaust & intake durations play a large part in your cars power band, but be careful here, getting this wrong can upset the idle and make the car hard to drive in traffic. You'd need to follow a camshaft upgrade with other mods and finish with a performance chip to fully realise your gains.

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 tuning upgrades are done can usually be traced to fuelling or timing issues.Upgrading the injectors is another beneficial modification and will deliver sufficient fuel.

A fuel pump will only deliver a finite amount of fuel, so you may need to uprate this if your injectors are demanding more fuel.

Intake and Exhaust Tuning.

Now we move on to the intake and exhaust and ensure proper flow through the engine. Air induction kits will only help to boost power if your air intake is restricted! Adding an induction kit to most small engines will see ZERO LOW END POWER GAIN AT ALL. If you have heavily modified your engine and it's need for air INCREASES DRAMATICALLY then an induction kit is the answer and will help remove this restriction.

Induction kits can work well on turbo engines and larger engines (if supplied with a suitable cold air feed or air box), generally though we'd just recommend for Mii engines you should just fit a performance panel air filter preferably made from cotton.

Sports exhausts increase the flow of gases through the engine. But if your exhaust pipe is too large, ie: it's over 2.5 inches bore, you will lose a lot of the flow rate and end up sapping power and torque.

Airflow through the head can be dramatically increased with some professional flowed (porting and polishing). These should match and be setup to take into account any other engine mods. When you tune up your Mii you will discover that the standard clutch starts to complain so get an uprated clutch. The best mods we recommend for your Mii are Remapping or piggy back ecu, fast road cam and air intake and exhaust.

NASP engines do not achieve big power gains if you remap them, unless you have done extensive modifications. With turbocharged engines this is another story. A remapped turbo will give impressive power gains and take full advantage of the strength of the block. The most impressive power gains for NASP engines usually involve the addition of forced induction. Turbos are generally harder to add than a supercharger. With a turbo the power curve is related exponentially to the engine speed making it harder to map.

Superchargers will give a boost which is correlating to engine speed so is easier to map. Adding forced induction will generally require a lower compression ratio or water injection.

Handling/Suspension upgrades

Many Mii owners uprate the handling of their cars with uprated suspension mods as a priority, this will certainly increase your enjoyment of the car.

Putting a small amount of negative camber at the front and a few degrees of toe out, will usually benefit your Mii in handling and cornering.

Drop the car by as much as 26mm - 38 mm and fit motorsport grade stiffer dampers, bigger drops will need other modifications in most instances.

Alloy wheel upgrades.

As alloy wheels are less heavy they improve performance and they can help to cool the brake disks. Get a good directional tread pattern tyre to improve your handling and help improve traction on your Mii. We should point out that although they can look cool on the Mii large alloy wheels 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.

For this reason we would advise sticking to a maximum wheel size of 16 inches, although we know some of our members have with bigger wheels with no problems.

There is a more updated version of this Seat Mii Tuning article on TorqueCars.com.

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

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