A "Base" map from 1 tuner will be totally different from the next. I have seen so many cosworth conversions that have had a so called "base". When looking at the map its a random cosworth map or not even the correct spec for the engine. EVEN when they have been told it is by well known tuners.

The best method for a base. Is to speak to a tuner that has a massive database of previous map'd engines.

So the done thing is to search the computer for previous maps that will be the best matched to the spec of the engine. A base like this is 90% if not better, matched to the engine its for.

This then leads to less time needed for tweaking and getting it perfect than any other "base" you could find.

= cost effective and quick. I guess a "base" like this is £50 worth.
Some cars never need anything else touched after that base map.

However if you needed or wanted a live map done, you would only expect to pay £150 as it wouldnt take that long to perfect the map. Couple of hours of driving with a laptop worst ways while your with the tuner seeing and getting the first hand info as it happens.

No need to leave the car with the tuner, then come back X amount of days later. To be told it took days to complete, used loads of petrol and getting charged £500+ for the same thing as above.

Only my thought obviously.