
Our members frequently talk about their latest mods and power figures. Many of our members have remapped their diesel engines and boast of more power, better economy and unchanged reliability.
But do the claims live up to reality? What sort of power figures can you get from a diesel remap? Diesels have really come so far in a very short time.
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.
Clutch tuning: performance clutch modifications and triple plate clutches setup
The clutch takes the engine power, and puts this down through the drive shaft, to the driven wheels on the road but allows you to disengage the engine whilst performing a gear change.
Contact like this requires a lot of grip and a fast response. The more power you have the harder it is for the clutch to operate.
Low ratio sport gearbox setup and selection.
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.