Well, I can´t talk about LFS because I do not have the time to drive it frequently. Real life plus league management plus the GPLPS plus the GPLmods Team activities do not let me dedicate time to other carsims than GPL (mainly) and NR2003, GTP mod mostly. I tried GTR and rFactor this year but I am really involved with carsims that, as a frustatred racing driver from the 60s , let me drive the cars and tracks I like the most, so there goes my time and dedication.
I am not saying the modern cars or tracks are worst than the old ones. It is just that I do not like them. If you make me choose between a 1967 Ferrari 312 F1 and a Ferrari F1 2006, well, you know the answer, don´t you ?
Anyway, after being in contact with modders that are working with other car sims, I think that one must be very careful before stating a car sim is better than other one, just because the physics´ engine is newer. FOr instance, GPL has around 120 parameters for each of the 7 cars + around 30 additional parameter for 5 types of tyres. Afaik, rFactor has about 500 parameters. In theory, rFactor seems to be much more advanced than GPL, but the problem is that, to make realistic physics you need to know real life parameters, which could be a problem is we talk about cars from the 60s, even from the 70s and 80s. Those parameters include chassis, suspensions, gearboxes, differentials, tyres, engine torque/power curves, etc, all with enough detail to match the parameters you need to fill in to get decent physics. The problem just get worst if you need to fill in 500 parameters instead of 120, so there are chances you may need to make too many guesses and spend lots of time without getting the proper handling/performance.
This is not about just getting similar laptimes at the same track. You need to know top speeds at certain tracks, you need to keep tyre temps below certain values, you need to know how the tyres used i.e. in 1967 really worked, which will have a decisive influence in the design of the suspensions. So, if you are working with a car sim that simulates a modern F1 car, I would say that it is almost useless to simulate a 1967 F1 car, unless you are ready to spend countless hours/days/months/weeks, or even years, looking for data and testing, not to mention the graphics´ work, and even in this case, the results may not be the right ones.
So I would say that, if you would want to mod some 60s or pre-60s racing car, for the moment, GPLhas the best engine. Newer than that, probably rFactor or GTR2/GTL. In any case, you need some historical tracks to test the physics. Otherwise, it could be just a theorical exercise.
That is quite true. The GPLmods Team is working on some major updates to GPL as we know it. These updates are not new mods.
FYI, iRacing never tried to stop the GPLmods team from patching the gpl.exe and, when asked by us, they said we could continue working with GPL at will. Their focus was/is on NR2003.exe, NOT in gpl.exe.