Vented bonnet and body vents for a motorsport look.

"Vent your frustration"

Complete the motorsport look with a vent in the bonnet. These can range from subtle slits to a honeycomb of vents that cover up to 50% of the bonnet area. Popularised in teen tuning films the vents are certainly here to stay.

They do perform a useful function in keeping the under bonnet temperatures down and help with performance, which is a subject we discuss in the torquecars tuning section more fully. The larger the vent the bigger the effect this will have on the cars aerodynamics so don't go too mad.

Before you take an angle grinder or jigsaw to your car plan in advance. Mark out where the main support frame is and avoid cutting it as this will dramatically affect the rigidity of the bonnet.  On a frosty morning if you run the engine the supports will generally be the last part of the bonnet to defrost so this can be a fool proof way of approximating their whereabouts. Otherwise use large sheets of paper stuck together to fabricate a pattern from which you can decide where to make the cuts.Using black card you can see what the vents will look like and these will also make a handy template for your cuts.

There are a number of methods available. Cut your bonnet and fabricate the vents yourself. This is the cheapest option but you will need to roll the edges of the cut so they are smooth and it is hard to get a good straight symmetrical cut in the bonnet.

Please don't attempt to cut the bonnet while it is still on the car, even if you have propped it open as this is the best way to get an off symmetrical cut and or seriously injure yourself. You will also need to check where the main under bonnet supports are before cutting to make sure you don't undermine the strength of the bonnet. 

The most expensive and best looking route of getting a bonnet vent is to buy a bonnet with pre-cut vents or moulded vent panels as in the picture above and then you would apply a protective mesh underneath them. This undoubtedly gives the best finish and the carbon fibre bonnets look great. This method insures that you will have a smooth professional looking finish and you can leave the bonnet unpainted or paint in a matching or contrasting colour or even add a really cool paint effect.

Alternatively you could buy stick on vents and use these to finish off your diy cut outs. This can be a handy way of finishing off a DIY cut job but you must spend  a great deal of time blending it in with the rest of the bonnet and take more time spraying and sanding to get a seamless join. The better quality the plastic part you use the better the end effect will be. Use the plastic painting and car spraying articles to guide you and help get the perfect finish but use twice as many coats and sand down between coats if you want a perfect finish.

Finish off the new vent with a good quality of mesh. Various types of mesh are available and the mesh can be painted black, polished or given a paint effect finish. Always ensure that if you go with a polished metal finish mesh that the metal will not rust as this will not only look awful but will quickly spread to other parts of the car.