SMART Forfour Tuning

"Thank you for reading our SMART Forfour tuning tips."

The Forfour is a great tuning project to carry out. If you do your homework then you can create an awesome Forfour but don't be fooled there are lots of performance parts out there that will simply not suit it read our unbiased guides first.

We review and look at Forfour tuning and provide tips on the optimum upgrades. SMART Forfours offer good returns when tuned and with the right upgrades you can dramatically maximise your driving opportunities.

Tuning tips and articles

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

Handling/Suspension upgrades

Handling modifications are at the top of your mod list for the Forfour.

Good suspension tweaks that substantially enhance handling for the Forfour include a couple of degrees negative camber and 1-1.5 degrees of toe in or out on the front wheels. Toe in for stability, or Toe out to improve cornering. It would also pay to improve the brakes, by adding larger discs and or higher friction pads..

We suggest that you fit modified suspension and lower the car by 29mm - 36 mm. Larger drops require arch work - especially on models already equipped with performance suspension.

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

Following our guidance for tuning your Forfour you will end up with a practical hot car that will potentially beat bigger cars.

Sadly with smaller engine sizes you are wasting your time spending money on modifications, so if this applies to you get yourself an engine swap then apply the following mods.

Power mods.

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

Getting the correct grade of uprated modifications for your planned usage of the car is vital. Stage 3 motor sport parts just won't work well on the road making the car difficult to drive.

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Best Engine Mods for your car

  1. Mapping - 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, Remap, Alloy wheels, Lighter flywheel, Suspension upgrade (drop 29mm - 36 mm.), Panel air filter.

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

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

Your goal when modding the engine should be a flat and wide torque output. You don't want all the power to be at the top end unless you are creating a motor sport car.

In this article we shall give a brief overview to the best modifications 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.

A fast road cam usually works out as one of the best NASP power modifications you can do from a single upgrade to your engine.

The exhaust and intake valve timings play a huge role 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 release the power gain.

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

Using higher octane fuel is another option if you find you are suffering from pinking or premature ignition on your SMART project after fitting other modified kits. Upgraded injectors will enable you to supply sufficient fuel to the engine.

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

Intake and Exhaust Tuning.

The next area for modification is the intake and exhaust. Contrary to popular belief there is often a small if any power gain reached by fitting an induction kit, they only become beneficial and are recommended after you boost the engines power to the point where the standard air intake box cannot cope!

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 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.

Do not go with the widest exhaust you can find this will slow up the exhaust flow rate - the best exhausts for power gains are usually between 1.0 to 1.5 inches. It is the shape and material more than the bore size.

Polishing and porting 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 When you start tuning your Forfour you will find that the standard clutch starts to fail so get an uprated clutch. The best mods that we recommend for your Forfour 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 large power gains and fully release the potential power of the engine. Adding forced induction will see big power gains but this is usually too expensive to be cost effective. Turbos are generally harder to add than a supercharger. It is more challenging to map a turbo as the boost builds exponentially with engine speed.

The nice proportional boost and rpm characteristics of the supercharger make them more straightforward to map. To cope with forced induction you will usually need to decrease the engine compression ratio .

Alloy wheel upgrades.

The benefits of alloys include lowering your unsprung weight and more efficient brake cooling. Pay attention to your choice of tyres (tires) for your car, a good directional tread pattern tire can really enhance your cars handling. We'd like to point out although they can look cool on the Forfour 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.

Although some people have with bigger wheels without issues we would restrict ourselves to a 15 inch rim size as the maximum.

If you would like to know more, or just get some friendly advice on Tuning your car please join us in our friendly forum where you can discuss Forfour options in more detail with our Forfour owners. It would also be worth reading our unbiased SMART tuning articles to get a full grasp of the benefits and drawbacks of each modification.

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