Exhaust systems  
Back boxes
Once again there are plenty of options on exhaust systems. Firstly, back boxes. If you believe that by fitting a back box to your car, you will get more power, then I'm sorry to disappoint you. If you're lucky, and I mean extremely lucky, you may receive an extra 2 bhp. They are fitted for two reasons: appearance and a deeper engine tone. You won't be struggling for choice with back boxes, there are plenty available on the market ranging from anything upwards of £70.

Full exhaust systems
A full exhaust system joins on either at the cat or the bottom of the manifold. The theory behind them is that they use a wider pipe allowing more engine gases to pass through given a better bhp at high revs. It also will store a little backpressure for help in low rev pick up. Full systems are costing anything from £150 up to in excess of £350. Also, buy stainless steal, it will last longer than any other steel exhaust. An ever-increasing tuning mod these days is a Manifold due to the genuine increase in power. The best ones out there are the 4-1 by GMC or 4-2-1 by Supersprint. The standard manifold holds a lot more back pressure and therefore loses the car the most power, by replacing this it will free up a lot more high-end torque. A 4-1 manifold will loose a lot more low-end torque than a 4-2-1 though so bare that in mind if a lot of your driving is at slow speeds in built up areas. One thing thatís worth noting is that performance manifolds sit a lot lower down than standard, so if you are running a low car, you could find yourself grounding out a few times. Just so you know, the 4-2-1 sits a lot higher up than the 4-1, due to the pipe setup! A replacement bypass tube (de-cat) for the catalytic converter is also a good choice for helping with increase performance and throttle response. But, and it's a big but, they are not legal and will fail an emission test, meaning that before your MOT, you will have to get it replaced, this is only a quick job though and should cost much to change. The only worry you have is that police can now do on the road emission tests, although Iím still to hear of a case of this happening. The alternative is to buy a performance cat's instead which are legal but they are very expensive. The best setup I would recommend is a exhaust system such as Magnex, Devil or Peugeot Sport, as they are very reliable and work well, followed by a Magnex De-cat (as its stainless steal) and a Supersprint 4-2-1 manifold. Depending on the state of your engine, this could all be good for 10-15bhp and a nice bit of added torque.

De-cat pipes
A replacement bypass tube (de-cat) for the catalytic converter is also a good choice for helping with increase performance and throttle response. But, and it's a big but, they are not legal and will fail an emission test. Meaning that before your MOT, you will have to get it replaced, this is only a quick job though and shouldn't cost much to change. The only worry you have is that police can now do on the road emission tests, although Iím still to hear of a case of this happening. The alternative is to buy a performance cat's instead which are legal but they are very expensive.

Exhaust manifolds
An ever-increasing tuning mod these days is an exhaust manifold due to the genuine increase in power. The best ones out there are the 4-1 by GMC or 4-2-1 by Supersprint. The standard manifold holds a lot more back pressure and therefore loses the car the most power, by replacing this it will free up a lot more high-end torque. A 4-1 manifold will loose a lot more low-end torque than a 4-2-1 though so bare that in mind if a lot of your driving is at slow speeds in built up areas. One thing thatís worth noting is that performance manifolds sit a lot lower down than standard, so if you are running a low car, you could find yourself grounding out a few times. Just so you know, the 4-2-1 sits a lot higher up than the 4-1, due to the pipe setup!


Article written by Ian Dews. 'Courtesy of Ian from Pug106GTi.com'