Theoretically, they are the same - bar the changes people have said above...
That said - in the ones I've mapped, it seems easier to extract power from them. For example, on a 306 HDi, with the stock r65 pump on, you tend to run into difficulties with the pump holding pressure with big fuel requests at around 300lbft and 165hp. You can do it, but you feel you are working against the car.
On the 307's I've done, 320lbft and 175hp can be done pretty easily, without the ECU cutting power, with the car totally, stock (bar a single mass conversion and clutch upgrade).
On "themilkman"'s car, we mapped it with just a decat, and straight pipe and it made 300lbft and 175hp with very few actual ECU mods. It drove like a stock one!! And, there was more to come, even on the stock 1500bar rail sensor, but then he sold it and bought a Leon Cupra TDi before we had finished playing.
Maybe it's just they are a bit newer, have done less miles etc... but that's my experience.
JP
That said - in the ones I've mapped, it seems easier to extract power from them. For example, on a 306 HDi, with the stock r65 pump on, you tend to run into difficulties with the pump holding pressure with big fuel requests at around 300lbft and 165hp. You can do it, but you feel you are working against the car.
On the 307's I've done, 320lbft and 175hp can be done pretty easily, without the ECU cutting power, with the car totally, stock (bar a single mass conversion and clutch upgrade).
On "themilkman"'s car, we mapped it with just a decat, and straight pipe and it made 300lbft and 175hp with very few actual ECU mods. It drove like a stock one!! And, there was more to come, even on the stock 1500bar rail sensor, but then he sold it and bought a Leon Cupra TDi before we had finished playing.
Maybe it's just they are a bit newer, have done less miles etc... but that's my experience.
JP
JP