LMP2 Regs
Homologated series production engines
Normally aspirated, max. cubic capacity 5,000 cc (8 cylinders max)
Petrol ------ Supercharged petrol: 3,200 cc (6 cylinders max)
Diesel ------ Supercharged diesel engines banned
"LM P2 engines must have a production run of at least 1000 examples in 12 months and come from either a GT or a large-scale series production car. Their power output must not exceed 450 bhp while staying within the following cost range: max. sales price: 75 000 euros, revision costs, 35 000 euros (30 hours use between two revisions); Rent: 1650 euros per hour of use."
Note: 'supercharged' in french means either supercharged or turbocharged, their meaning here is turbocharged.
"The cost of a new car (engine not included) must not exceed 345 000 euros (see below for engine prices)."
This means the Oreca 03 chassis is the best choice as it is ~180-200k euros and is so cheap because it's produced in large enough numbers to make it cheap.