Gearbox – Lower ratios give better acceleration times and lower fuel economy. Six or seven speed boxes are better matched to modern engines.
Most street applications are closer 1st and 2nd gear ratios for that off the line 0-60 boost or for the fast exec a lower 2nd and 3rd ratio give improved overtaking flexibility and 30 – 70 mph acceleration with a high 4th and 5th gear to give motorway fuel economy.
Principles of porting an engine and big valve conversions
The inlet and outlet ports on the engine block are usually larger than those of the manifolds that connect to them.
This allows for scope in the manufacturing process to allow for mismatched alignment.
Generally the engine ports are larger in the upstream flow direction avoiding turbulance but power gains can be made by matching these up.
Turbo tuning – Aftermarket OEM turbos upgrade kit.
When it comes to Turbo tuning you have pretty much unlimited potential and a wide selection of options.
The more power you want from a turbo the greater the amount of heat it will generate and the bigger the stress on the internal components.
Chip Tuning – better engine management.
The days of fiddling around in the engine bay with a spanner to make the car go faster are numbered.
Modern engine computers (ECU’s) take over many of the controls of all aspects of engine management from timing to fuelling and more.
This actually means you get better power, a cleaner burn and more reliable engine but it does not mean the end of tuning.













