Tuning the SMART Roadster
"Thanks for reading my SMART Roadster tuning tips."
The Roadster is a brilliant tuning project to execute. With the right mods your Roadster can be transformed into a stunning project. Don't waste money, do your homework and follow our unbiased guides to each performance upgrade to avoid disappointment.
Handling/Suspension upgrades
Many Roadster owners uprate the handling of their cars with fast road suspension mods as a priority, this will certainly increase your enjoyment of the car.
Good suspension tweaks that radically benefit handling for the Roadster 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 would go to a maximum drop of 27mm - 37 mm. on most models. You risk rubbing on the arches if you go lower than this.
Our aim in engine tuning should be to increase peak torque at the top end.
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 parts are usually installed by our members, decide how far you want to push your car before you begin.
Getting the right tuning mods for your planned usage of the car is essential. Stage 3 motor sport parts just don't work well on the road making the car difficult to drive.
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How to tune your car
- Improve the handling
Focus on Suspension improvements, such as coilovers and make sure the bushings are in good order and that the alignment is correct. Then focus on improving the brakes, with a big disk brake conversion kit and fast road brake pads.
- Remove restrictions
Focus on the intake and exhaust with filters being the common point of restriction in a tuned car. Intercoolers may also become restrictive on turbo engines so this may also need to be uprated.
- Burn more fuel & air
Increase the fuelling so it matches the air coming into the engine. The ratio is important so you need to improve the fuel pump and injectors, so the head mods, big valve conversions, fast road camshafts and forced induction upgrades extra supply of air is adequately met.
- Test and replace any weak parts
Weak areas are commonly the clutch, the turbocharger and pistons and crankshaft in a highly tuned engine. Makes sure these components will cope with your power aspirations.
- The Tune or Remap
A cars ECU controls the fuel, timing, spark and even the turbo in some cases, so to fully extract your gains you should remap the car last and this will fully release the power. Some cars are easy to map, and others require piggyback ECU's or aftermarket ECU's but this is the most vital step of your tuning project.
Modifying to Stage 1:
Panel air filter, Lighter flywheel, Alloy wheels, Suspension upgrade (drop 27mm - 37 mm.), Remap, Sports exhaust.
Modifying to Stage 2:
Ported and polished head, fuel pump upgrades, Fast road cam, high flow fuel injector, Power/Sport clutch.
Modifying to Stage 3:
Engine balancing, Adding or upgrading forced induction (turbo/supercharger), Sports gearbox, Competition cam, Internal engine upgrades (pistons/head/valves).
Peak power is all well and good but for a drivable and fun car you need a wide torque band and perhaps extending the rev range.
In this article we shall give an overview and introduction to the best upgrades for your car, but we'd encourage you to spend some time on the site looking into the details of each type of performance modification.Fast road cams offer one of the biggest power gains for your money as far as a bolt on motorsport modifications goes on a NASP engine.
The exhaust & 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 challenging to drive in traffic. You'd need to follow a cam upgrade with other mods and finish with a performance chip to fully realise your gains.
Don't forget to pay attention to the fuelling when you are increasing the power - it makes the car more thirsty.
Using higher octane petrol is another option if you find you are suffering from detonation or premature ignition on your SMART project after fitting other performance kits. Larger injectors will enable you to supply sufficient fuel to the engine.
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. Please note that WE DO NOT FEEL YOU GET POWER GAINS FROM INDUCTION KITS, unless you have tuned your car a lot and are finding that the standard air intake has become a restriction.
For most Roadster engines TorqueCars would suggest you just go with a washable panel air filter. On heavily tuned engines and turbo vehicles an induction kit will help release the power providing you address the problem of needing cold air.
Do not go with the widest exhaust you can buy this will reduce the exhaust flow rate - the best exhausts for power gains are usually between 1 to 1.5 inches. It is the shape and material more than the bore size.
Airflow through the head can be dramatically increased with some professional head porting and polishing. These should match and be setup to take into account any other engine mods. Your clutch can slip as the power goes up if it starts to suffer and the standard clutches are only ever good for power gains of up to 40%. Fit a sports clutch to avoid power leak through the transmission. The best mods that we recommend for your Roadster are a remap especially on a turbo, a fast road camshaft and sports exhaust, with a good air intake.
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 phenomenal power gains and fully release the potential power of the engine. The most phenomenal power gains for NASP engines usually involve the addition of forced induction. It is generally simpler to bolt on a supercharger than it is to install a turbo. Turbos give boost in exponential proportion to increasing engine speed and this can make mapping difficult.
It is simpler to map a supercharger because the boost is correlating to engine speed on a linear curve. Decreasing the engines compression ratio will allow you to add forced induction, water injection may also help prevent detonation.
Alloy wheel upgrades.
Alloy wheels can help the brakes cool down and are usually less heavy than the steel ones. Pay attention to your choice of tyres (tires) for your car, a good track legal slick tire can really enhance your cars handling. The drawback to large rims on your Roadster is that you're changing your final drive ratio and this will have a negative effect on performance and acceleration.
Although some people have gone larger than this without problems we would stick to a 15 inch rim size as the maximum.
For more information on Tuning your car please join us in our friendly forum where you can discuss Roadster options in more detail with our Roadster 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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