Why are FFB difference ISI car and Non-ISI car?

[thoyun22]

Why are FFB difference ISI car and Non-ISI car?

ISI car has unique FFB. Especially Open-wheel is very extraordinary... Why? Aerodynamics?
I think that ISI car is very senstive about UNDERSTEER.

Non-ISI car such as URD, BES, IFS3 etc.. has ordinary FFB. They are similar to others(AC, GSC, iRacing)

Why difference? ISI and Non-ISI.

Which is more realistic?

 

[David O'Reilly]

I think I know what you mean.
For example the FR 3.5 has amazing FFB when setup nicely, so too the F ISI. Then the ASR 1992 cars despite great handling dont have that front end feel.
I'm not tech enought to say why.
Maybe ISI are good at making cars with realistic FFB in their own game?
Some non ISI cars are conversions too (BES 1.0, ASR 1992)