4WD cars are difficult because they are different, too much power pushed forward causes a push or understeer like front wheel drive cars. But it can be used to help tame very loose rear heavy cars like Lambo's. Difficult to explain but I will try.
First, what I would suggest, is trying to tunes. My 550pp Gallardo (
here), and a FITT tune from
@Thorin Cain of a Murcie SV (
here). My tune is not bad but should help you see my approach,
@Thorin Cain 's is probably the best Lambo tune I have personally ever driven and it has some stock parts. Take Thorin's to Midfield and drive for as long as it takes to get comfortable with it. That will give you an idea of how a really good one feels and the advantage 4WD can give.
Second, LSD and centering diff are huge. Use them. LSD decel can really help control the rear if you set it higher, leave at 20 and slowly climb until it gets too far then come back down. Center diff can also be used. For high hp, lower front setting such as 10:90 will make the car handle like an MR, higher front will calm the rear from sliding but will induce some understeer. Settings like 45:55 or 50:50. But higher will allow for some really good launch out of corners, mid corner will suffer and sometimes entry.
I would set the springs first to a starting point, higher in the rear. Put all dampers at 5/5, and ARB at 4/4. Set toe to -0.05/0.20. Then concentrate on getting the LSD and Center Diff where you want them. If you use ballast, don't put it all the way forward, 35-40 position should help balance the car. For LSD, start with something like - intial 8/10, accel 20/20, decel 10/20, and Center Diff at 40:60. Play with LSD and center diff until you get the car mostly where you want and play with suspension after you are satisfied. 4WD takes longer, but if you start there you will be heading in the right direction.
I may be wrong and others may do it differently, but that's how I do it. If you want a short cut, car of the month for March was the Gallardo and there were some really fun tunes, you can find them
here you can look at the settings and read reviews to help see how others set theirs up. Then there is Car of the Month January
here where the R33 GT-R was featured, again you could look at setting and reviews. That should help I hope. And if you need more, or have more questions, I will try to help. But seriously, try Thorin's Tune if for nothing else but the pure enjoyment of it.
Good luck, and thanks for starting what I hope will be another 1000 posts