Dont torque to me like that!

Internal engine modifications
Careful selection of internal engine modifications can lift an engine from a docile supermarket cruiser to a rally spec dirt thrower. While it is tempting to throw in every modification you can it's worth noting that they don't always work well together ie: a gas flowed head with a sport cam produces less power than it would with just one of the two modifications. You want to avoid ending up with a high BHP engine that has an unusable low torque output!!!!: items include high compression pistons (increase the compression ratio) Low compression pistons (reduce the compression ratio and used with some turbo applications to prevent ignition problems and reduce the effects of turbo lag. Skimming the head also increases the compression ratio and to avoid detonation with low octane fuel a low compression piston is used.

Flowed head – the internals of the head are polished and channeled to allow the induction and exhaust gases to flow more freely. Inlet diameter and other measurements are taken and the best flow rate is calculated and the engien channeled out accordingly smoothing the internals and sometime a little turbulance is added to ensure a good air/fuel mix inside the combustion chambers. Specialists can increase EITHER the torque output of the engine or raise the maximum BHP and EITHER improve or reduce fuel consumption sadly you can't have everything you have to decide what the optimum rev range that you use is then specific gains can be generated in that area. I had my head flowed for Torque gains, where peak torque now comes in almost from 1000 revs and I have also got much better fuel consumption - up by a stonking 10mpg (Other work has been done on the Head which also contributed to this gain)!!! I do not seem to have more power in the higher rev bands near the redline but I never really go that high so my engine is perfect for my driving style. The angle of the inlet valves, enlarging the inlet and exhaust valves and increasing the lift on the valve can all aid the way gases flow into and around the head.

Re bore the cylinders to create a higher capacity engine – check that your engine management system is able to cope or can be adjusted to suit this will also require work on the pistons as they will need to be switched for wider ones. A stroker kit also increases the cylinder capacity and typically comprises conrods, crank and pistons and generates more space in the cylinders for air and fuel.

Crank grind/polish While the crank is ground it is worth balancing all of the other internals of the engine - your redline will be higher if the engine is balanced and a lighter polished crank gives less friction and releases more power from the engine.

Sport computer – changes the timing characteristics of the engine and is usually perfectly matched to your engine, fuel choice, driving style and car condition rather than the standard makers best guess setup which can cope with pretty bad servicing and poor quality fuel. Massive power gains and better fuel economy are available as is a high revs sport power setting and a low revs economy setting. The downside is that you have to keep the engine in peak condition changing the plugs regularly and fastidiously following the service intervals. The cars which benefit the most from a sport computer are those which are fitted with a turbo or supercharger. You can buy a standard plug in chip but it is much better to have the sport ECU set up specifically for your engine and have a custom map - again this can be set up to give better fuel economy, a lower peak torque cure, better acceleration or higher top end power. Some ECU's are impossible to reprogram without the manufacturers diagnosic equipment - the Rover MEMS is a point in case. If this is the case with your engines computer you can add a piggyback device which gives false readings to your cars ECU and takes over control of Fuel, Ignition and boost control.

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