I really couldn't say, because I never kept any sort of a log of what I changed. Any combination of the DX/Y values, flex, xmu, friction limit angles, relaxation length, hub masses.. Sorry, I can't be any more specific. Besides, the Jag may not even have a problem as such. It could be down to individual players' wheel settings and such. Various people with the same wheel seem to have very different opinions on some of the cars in AC :-\.
It's really quite complex the way the values interact with each other. When I was tweaking my tyres I found that anything more negative than -0.02 for the DX/Y1 values were undrivable, yet I've seen tyres that work fine at 3x that. Crazy.
Hmm, I think I'll send a pm to aris to see if he responds. As far as I know he was one of the guys doing tires and physics for the gtr2 power&glory mod so he should have good bit of info about the tires these suckers have.
I'll check that reducing dy0 but again I just don't want to it blindly. So I need to figure out if it works why it works.
I did check some rf mods. And nope. I don't see such pattern.
It is odd because on my car I can pretty much change the dx1/dy1/xmu values in a major way without causing big difference to the car handling. What I have found is that my tires seem to be (or were at one point) somewhat camber sensitive.
To me it feels like there's very little or no caster angle- is that set independently or simply a result of the locations of suspension attachment points?
Meh. I just drove around vallelunga and noticed the wheel holes show through. For some reason ac doesn't show the bits behind the wheel but shows what's behind the car...
I have played around, and I think this is better control wise for a FF wheel, but each to their own I guess. Also changed the sound ( just because I can) as I watched some V8 video's on U tube
Let's say that a V8SC has
- 24 degrees of steering angle
- 400 degrees of rotation (so a bit over 180 per side)
Steer ratio would be 400/24 = 16.7
By using the below method to get the rod length, I get 0.00261.
So the final values for control would be as below, feels alright.
STEER_ASSIST=0 ; Variable steer assist, speed relative STEER_LOCK=200 ; Real car's steer lock from center to right STEER_RATIO=16.7 ; Steer ratio LINEAR_STEER_ROD_RATIO=0.00261
A bigger problem is that as far as I can tell, real V8SCs run a minimum of ~-14 degrees of caster. The current geometry only gives -6.4. Perhaps that's why it lacks feel that upping the FFMULT can't fix.
I want a clean post for this so no edit. I was told that the iRacing V8SCs have a steering ratio of 13.56. Assuming 400 degrees of steering wheel rotation, 400 / 13.56 = 29.5 degrees of steering angle.
- All of the AC console INIReader errors fixed.
- -15 degrees of caster.
- 400 degrees of steering lock (lock to lock, 200 per side).
- 29.5 degrees of steering angle.
- 13.56 steering ratio.
- LINEAR_STEER_ROD_RATIO is 0.00296.
- FFMULT is set to 1.5 from because I suspect that the increased caster will help with feel.
I worked on the steering issue a bit more, changed some values. Now it feels better for me, of course take such comments from me with a tablespoonful of salt considering my steering input device.
suspensions.ini changes:
WBCAR_STEER= 0.390, -0.180, 0.122 ; Steering rod car side attach point WBTYRE_STEER= 0.108, -0.193, 0.149 ; Steering rod tyre side attach point
suspensions.ini original:
WBCAR_STEER=0.390, -0.180, -0.122 ; Steering rod car side attach point WBTYRE_STEER=0.108, -0.193, -0.149 ; Steering rod tyre side attach point
---
car.ini changes:
STEER_RATIO=12.5 ; Steer ratio LINEAR_STEER_ROD_RATIO=0.00248 ; Because of AC complex suspension geometry, you need to calculate manually the steer rod ratio
car.ini original:
STEER_RATIO=-12.5 ; Steer ratio LINEAR_STEER_ROD_RATIO=0.00216 ; Because of AC complex suspension geometry, you need to calculate manually the steer rod ratio
In summary, changed the steering rod attachment points to invert the steering ratio to be positive and adjusted the steering rod ratio using the method in the file comment.
Out of curiosity, where did you get the dimensions of the car? A modern V8SC's height is quoted to be
and just by looking at images, the Jag doesn't look taller.
I noticed that sometimes the car gets into very severe oscillations that takes ages and ages to settle, after hitting kerbs. I reduced the car's height by 0.2 to be close to the height of the road-going XJ12C which I saw quoted to be 1372mm, and these huge oscallations reduced noticeably while retaining the boat-like characteristics intact.
Also found that some of the vagueness in the handling was down to the setup as well, I used the one attached (remove .txt).
Well the box method is not supposed to be the exterior dimensions of the car exactly. But you also need to take into consideration the location of the cog (box becomes longer, wider or taller if the cog is further away from the geometric center). And also like phil said how much is the mass centered near the cog or more towards the edges. So the jag has more weight on the outer edges than the v8sc. Thicker steel (maybe), more heavier bodyshell, heavier windows, bonnets, doors etc.
And that steering of yours is antiackerman . Basically the outside wheels turns more than the inside wheel. Why it feels more stable and wonders less is because you have several degrees of toe and even more in corners.
eI found the car dimensions in various ways. First I just took the stock xj12c. Then in blender after I had finished the model so the exterior dimensions should be fairly close I then measured it in blender. I did lots of cross referencing to get the blender model correct so I now I have measured most of the stuff from that. Frontal areas for aero, dimensions of the car...
Well, this is odd. Yesterday I did steam integrity check for ac and now for me the car seems to have a lot more bouncyness. Before the bouncyness was not an issue for me but now I'm getting oscillations which causes the car to jump around. In the nordschleife the parts which used to not be problems (the early part of the track where you use those concrete/tiled runoffs to cut corners a bit. Or the super fast left hander into schwedenkreutz. Before I noticed there was alot of bodyroll and some bouncing but never so much I'd miss my lines. Now I'm bouncing off the track...).
Also I think I have solved the numb steering issue in the center. Scrub radius. I never assumed it would make such huge difference! First I moved the whole suspension sideways 10millimeters. A lot heavier in the center. Reduced to 6 millimeters and now it feels better I think. There is more weight and resistance in the steering. Which of course makes sense considering what the scrub radius does but I never assumed even 6mm can make such big change. I also moved the steering arms a tad.
If you want I can share the files.
Next I need to go back and double (quad-something-check actually...) those inertias. This time I'll go all out and decide that box system so I can get as accurate as the positioning of the individual parts on my calculator.
Lol I calculated the box dimensions.
What I have now in ac: INERTIA=2.4,1.5,5.2
What I should use according to my calculations: INERTIA=1.89,0.56,3.75
I think I've made a mistake... The actual inertias for the car were 2130 yaw, 469 roll and 1738 pitch. With mass of 1450kg.
I'd assume it is yaw. So if you calculate one you can probably use the same multiplier for the other inertias as well. So if the yaw dynamic index is too low then raise it and raise the other 2 as well using that same multiplier?
