Seat Mii Tuning

"Thank you for reading our Seat Mii tuning tips."

We love the fun Mii, it's small size and low weight mean even the smallest power mods make a difference.

It is both fun to drive and cheap to run, proving to be an ideal first car, or town car.

We get asked a lot about modding the Mii and we've pulled together all the tips and mods into this article for you.

The Mii is a good project car to do. If you do your homework then you can create an awesome Mii but don't be fooled there are lots of tuning kits 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

 

Handling/Suspension upgrades

Handling modifications are usually your first port of call for the Mii.

Adding a small amount of negative camber on the wheels and a degree or two of toe out, will dramatically enhance your Mii in handling and cornering.

We would go to a maximum drop of 21mm - 36 mm on most models. You risk rubbing on the arches if you go lower than this.

Don't just look at the peak power figures, you need to see the whole torque curve when determining if a mod is right for you Mii.

Mii make good sleepers if you debadge them and fit the most powerful engine upgrades and handling upgrades you can !

The best power gains come from larger engine sizes. The more you start with the bigger the return on investment so engine swaps are good value mods for small engined cars.

Engine Tuning.

Typically these mods are usually carried out by our members, decide how far you want to go before you start.

Getting the right sports upgrade kits for your planned usage of the car is a time and money saver. Stage 3 motor sport mods just won't work well on the road difficult in stop start traffic.

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

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

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

Peak power is all well and good but for a drivable and fun car you need a wide power band and perhaps extending the rev range.

In this article we shall give your a good starting base to the best performance parts for your car, but we'd encourage you to spend some time on the site looking into the details of each type of performance mod.A fast road cam is widely accepted as one of the best NASP power modifications you can do from a single upgrade to your engine.

It maximises the intake and exhaust durations and pushes up the power if done right. Ideally you'd add other mods and finish up with a reflashed ECU. TorqueCars would caution you not to go with a motor sport cam as this affects the engines idling and general town driving characteristics.

You will need to ensure that the engine is not starved of fuel so will need to increase the fuelling.

Using higher octane fuel is another option if you find you are suffering from detonation or premature ignition on your Seat project after fitting other motorsport mods. Bigger injectors will enable you to supply sufficient fuel to the engine.

If you've uprated your fuelling with bigger injectors you will also need to get a bigger fuel pump to supply it.

Intake and Exhaust Tuning.

The next area for modification is the intake and exhaust. Induction kits will only help to add performance if your air intake is struggling! Adding an induction kit to most low power engines will see NO 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.

Maximum power gains come from a full induction kit with a cold air feed on heavily tuned engines, this can be sited within an air box but a performance panel filter should suffice for most applications. TorqueCars suggest you use a panel air filter as these are easy to clean and maintain and generally perform better than paper ones.

Sports exhausts balance the flow of air through the engine. But if your exhaust is too large, ie: it's over 2.5 inches bore, you will lose a great deal of your flow rate and end up lacking power and torque.

gas flowing the head will allow you to maximise your air/fuel charge. Leave this to a professional though with a proper flow bench and machine tools A good fast road performance clutch will help to keep that power going where it should. Never cut corners or think that a standard OEM clutch to cope. The best mods that we recommend for your Mii are fast road camshaft, remap, induction and exhaust, suspension.

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 massive power gains and fully release the potential power of the engine. Despite the large cost involved adding forced induction to a NASP engine will give large power gains. It is generally easier to bolt on a supercharger than it is to install a turbo. Turbos increase power in exponential proportion to th engine speed and this can make mapping difficult.

Superchargers however will give a boost which is proportional to engine speed so is easier to map. Alternatively you could perhaps fit water injection to control knock.

Alloy wheel upgrades.

Because alloys are lighter they improve performance and they help to cool the brake disks. We can't go into too much detail here about tires but they are how the car puts the power down on the road so are a critical choice.

directional tread pattern tires work well on Mii, and make a big difference over budget tires. Large Mii alloy wheels can decrease performance. If you get big alloy wheels you will be changing your final drive ratio.

Due to this fact we would advise sticking to a maximum wheel size of 16 inches, although we know some of our members have fitted larger wheels with no problems.

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.

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 mods were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our guides and tips are kept up to date.

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