[Spenny_b]

IME, it's not so much the cost of the hardware or ECU, or even a decent loom (which is $$'s).

More importantly, the mapping effort to get a REALLY nice, driveable engine is a tonne of money. Mapping for the top end is easy. Self learning has removed many hours from what was once a very time consuming exercise, and can get you there-or-therabouts very quickly indeed. From that you can tweak and refine.

But, making a car thats well behaved, pulls away without stalling, cold starts each and every time, behaves itself on light throttle in traffic, etc, etc, is not the work of a tea break.

Anecdotally, I heard that Porsche invested 40,000 man hours mapping the 996TT, and Bosch/Audi had one guy, for 6mths, with 6 cars available to him, doing nothing but cold start mapping on one of their RS models (iirc)

ETA - to put some context around the mapping costs, I had to reluctantly go and scare myself the other week, by sitting down and adding up the total spend for my engine project...which has turned out to be FAR from just an engine project...lots of refurbing, new brakes, wheels, suspension, etc....with all that considered, my mapping costs *so far* (we're not done yet) are about 12.5% of this project, quite easily going to reach 15% I would guesstimate.