TDI POWER

Firstly the tuning fuel economy thing; one of the advantages of diesel as a fuel is that it is capable of running at a wider air-fuel ratio than petrol, so that at idle speed it can use less and it can run really rich (but makes a lot of smoke). The way most diesel engines (and all VAG ones) work, is that there is no throttle so the engine always sucks in the same amount of air depending on its speed. The amount of power produced is dictated by the amount of fuel injected - more fuel = more power. In practice the amount of power produced is dictated by how much smoke is acceptable ie a diesel engine produces most power when making huge clouds of smoke...

So if you tune a diesel engine it only effects the fuel economy when you 'use it'; when you are at wide open throttle you will use more, but at a constant speed you will use the same or maybe a little less. YMMV

With the engine swap business I suppose it depends on how much power is 'enough'. If a normal chip for £500 gives 30 to 40 bhp, then you'll have to decide if you want 140 or 170 bhp (from a 100 or 130 bhp). In otherwords for £500 you could have an engine with much the same output as a pd130.

The rest of it comes down to money as you could make 250 bhp from a 100 bhp with new injectors (£600), fmic (£500), vnt-17 (£1000). Call it £2500 with a remap. The pd130 could get 250bhp without changing the turbo as it comes with a version of the vnt-17, saving £1000. But then 250bhp is really a 'race' engine and would smoke like a chimney...

The blocks on all the VAG diesel engines are much the same, different power outputs are made with different turbos and injectors (I realise this is a simplification).

What would I do? If the amount of power you have now isn't enough then i'd sell up and get a pd130, then remap that on the basis that you will kill the retail value of your current car if you swap the engine. If that still isn't enough power then I'd go for all the gucci stuff. If you don't want to sell, then I'd maybe look at a turbo and injector swap. A whole engine swap just seems a bit silly when they are much the same inside.

You want a turbo from a pd130 or pd150, they are both vnt-17 but the pd150 has better internals. That said the pd150 engine needs more pipework changing under the bonnet...

Injectors pd130/150 ones (i think they are the same).

Answers to all these questions and more can be found at www.tdiclub.com , just search and someone will have done it before. A us supplier for all this stuff is here www.kermatdi.com (i know your mate can get you this stuff but you need to work out what you want first!).