Outdated Petrol & Diesel V8 engines for the ETK 800/K series 4.2.1

Hello all,

I had some time during the holidays to work on this mod and I decided to completely rework the petrol V8 engine's JBEAM, it means that there's no change to the model and its physic (I didn't touched the nodes skeleton). The reasons that pushed me to remake it from scratch was mainly because I started this project a long time ago (mid 2020) and I was pretty unexperienced with engines so a lot of the engine's specs were really unrealistic. The 0.25 update changed a lot the sound of the turbocharger so they needed a rework too as their sound became really weird. The diesel engine remains untouched as he's fine in its actual state, however his turbochargers still sound pretty bad (due to the last update again) but I lack of time to work on them.

Quick changelog :
- Remade from scratch the Petrol V8 and his turbochargers specs : Lower torque in very low rpm, lower power in very high rpm, less linear behaviour with more torque in mid rpm, turbochargers build boost a lot quicker and have less lag, improved the sound of the turbos, peak power remains approximatively the same and a lot more things you will probably never notice
- Engine sound and node skeleton remains untouched
- Added new tailgate V8 letterings for the ETK 800/K courtesy of @RenAzuma66 however the configs are not updated due to lack of time (may come later)

Have fun !