Hey there. Been tuning a toyota celiac gt 1974 all day trying to get it to feel right. Just when I thought I was getting somewhere I benchmarked it against somebody else’s tune and really felt like my entire tune was lacking.
If somebody experienced would be able to take a look at my tune (gt: isBrayden) and tell me how I manage to get it to feel like either one of the tunes I tested against (gt: Kerosyn or WGTS Killswitch). I’m not asking you to copy their tunes for me, I’m just asking how on earth did they get their cars to feel that way?
I’ve tried stiffening the front and making the rear softer to extreme degrees and the best imitation I can get is just about opposite ends for arb and springs (front full firm, rear full soft) and really soft damping and bump rates for front and rear. But even then, there is a world of difference.
Please help me, experienced ones 
I am not in front of my console so can not try any of these tunes but what are you trying to achieve?
Everything you mention above is yelling understeer to me but I assume you do not want that.
There are a few open source tunes in the thread (page 25 and 26) in the following link https://forums.forza.net/turn10_postst82587p25_Weekly-Hot-Lap-Competitions-Hosted-by-HLR---WIN-A-CAR-PASS-this-week.aspx?=
I have tuned Celicas similar to my Torana that run well, but look at the other tunes as well, although they are different cars and even different engine position some of the same settings may help you understand what the settings do.
Understeer is the word. But they don’t seem to understeer mid-corner, only on entry and a little bit on full throttle. Feels like glue though. I’ll take a look at those open source tunes and keep this thread posted with my progress 
Those tunes are both awd so they don’t really apply to me, I don’t use awd cars. But I downloaded your 1971 Nissan skyline 2000gt-r tune (the body kit one) and that’s the sort of steering feel I’m after. The front understeers, but still grips and turns so it’s not really understeer, while the back follows nicely without ever stepping out. HOW?!? Witchcraft. I’m calling it.
Thats awd too from memory.
You’re right, it is.
The other two I’ve mentioned aren’t, I’ll have to wait till you can test them for yourself, they’re actually pretty similar in feel to your car.
I have not done much rwd tuning in FH3 but to get the back to follow read on.
First off tune the end you are not happy with so try these.
Increase rear anti roll bars
Increase rear bump
Decrease rear aero
Decrease decel diff
Increase accel diff (rear)
Change rear rebound up or down
Now in your build try decreasing front tyre width.
I’ve somewhat managed to mimic the front end feel with really stiff front end roll bats and springs, but I can’t seem to get the back end feeling as flat out of corners… suppose this is going to be a long run of trial and error lol.