I was in a room the other night and some guys wanted to run Nascar on Monza. At first I thought about leaving, but after throwing a quick tune on and driving a couple of laps I found the car pretty responsive for it's weight with lots of grip, and fun to drive with the big V8 screaming in the surround sound. So I thought I'd give your tune a try as I think this is something I'll do once in a while when I host.
For what it's worth, I use a DFGT, and my driving style is controlled but at the limit. I don't like cars that are loose, don't set my own up that way and I like to set up my brakes to trail brake, and if it's possible, I'm usually braking into the turn, right down to the apex on some tracks/corners, although not with 100% brake force of course. My car has oil changed but is not broken in.
I took my own tune out on the track, made a couple of tweaks and then ran some hot laps. Tire wear was an issue as you would expect on a car this heavy, but with my own tune the tire wear was at least even and while it slowed me down slightly as the tires wore, it remained in control.
My best laps in my own tune, with oil change but not broken in were in the 2:09's. I was able to run 3 laps below about 2:10.3 and the times began to rise as tire wear kicked in, but the car was still balanced, just with less grip.
Tune Review
Relative to my own tune, overall I found the car very difficult to drive, especially after the first timed lap. Once tire wear kicked in, which was significantly higher, the car became almost undrivable for me. The car felt pretty sluggish in both turn in and in mid corner grip relative to my own tune, especially on the big sweeping corners and through Eau Rouge.
Because of the heavy rear bias in the brakes, I could only brake in a straight line, which to me alone, cost at least 1 second per lap. Whenever I was on the brakes as I began the corner, the rear end would snap out. So I experimented being in the right gear before turning, or alternately, braking a bit later but being one gear higher, neither of which is preferable for best lap times, but was necessary in this case to remain in control.
The LSD did not work for me either. If you downshifted while cornering even slightly, that would also kick the rear end out. I try to correct for that when tuning, because I like to vary the timing of my downshifts to induce under/oversteer, depending on my positioning in the corner and whether I'm carrying excess speed or a lack thereof. With your LSD and brake settings you pretty much have to be set up for the corner before you begin turning, which doesn't allow brake/drivetrain adjustments on the fly to correct for small imperfections in entry angle and speed. I also found that around the second lap, the inside rear tire started lighting up even in second gear, which is of course lost traction and time, and in a Nascar, a lot of tire wear.
The transmission settings were ok but I think 1st needs to be a little taller, and 2/3 need to be more evenly spaced. I see where you're going with 3/4 being so close but I don't think that's necessary. 3/4 needs to be a little closer than 2/3, just not that close. I had first tall enough to use in 4 different corners, and in conjunction with the LSD settings it did not cause the rear end to kick out, making it smooth cornering in every gear.
Tire wear was a significant issue. It was considerably higher than my own tune and after the first timed lap it really affected the handling of the car. The outside front tire started lighting up, then into the second lap, at some points 2 or 3 tires were lighting up. Corner grip fell significantly in the second lap to the point where I couldn't really drive it with any speed beyond the third timed lap. This tire wear also affected grip under accel too, as I mentioned above, as early as the second lap the inside rear tire was spinning under accel.
Perhaps this tune is better suited to a DS3 user, not sure, have never driven one in GT5 so I can't say what the differences would be.
Best lap with your tune: 2:11.5
Best second lap: 2:13.5
When I first looked at the tune, my first impression was that you raised the back end to get grip and then the rest of the tune is fighting that extra grip. Essentially you have created the problem with one element of the tune, then tried to correct it with the rest of the tune.
Instead, my suggestion would be to balance the tune to begin with, with springs/shocks/ARB's, that are relative to the weight distribution of the car, equal ride heights (i usually start with 0/0),equal brakes (i usually start with 5/5), basic toe and camber settings or even 0/0 and an LSD setting of something like 8/15/15. Then tune the suspension for balance, without changing the ride height, as a front/rear ride height differential is not usually necessary on cars that are tuned for balance. Once it's balanced, fine tune with LSD, toe, camber etc.
If you take a balanced suspension tune, adding camber should add grip overall. Toe should help a bit with turning and high speed stability, LSD should help stop the rear tires from spinning and perhaps aid with cornering. I don't use these elements to balance the car, just to aid the balance that already exists with the suspension set up, in most cases.
Good luck and I hope that helps...
