I appreciate the time you’ve taken to describe some of the effects at play here, it’s really interesting, and it’s clearly a far more complex problem than it seems on the surface, but I also understand this isn’t the time to get too deep into it, so I’m not expecting this to spark any debate or warrant more response when there are better things to be getting on with.
I think there are competing things happening when you accelerate in a rear drive car, and the balance of what wins might depend somewhat on the car itself, as well as any fancy electronics potentially stepping in.
My analog RX-7 has wider tyres at the rear than at the front, and quite a linear and gentle power curve, so unless you’re extremely aggressive the load transfer plays a more dominant role in pushing the car out wide.
Which would be a combination of bigger contact patch mentioned here and more force pressing down on the tyre into the road surface.
The same goes for our MX-5 which has a more modest engine, but also equal width tyres front and rear. More power increases acceleration which sends more grip rearward compared to the front—which if at the limit mid-corner means a wider line. I guess an increase in speed in general also dictates a wider line if you were already at the limit, too.
Both of these cars have been used on track days and also at the AutoSolo events that used to be held in Rockingham’s car park. Applying the throttle on either car only induced more front end lift and understeer, as described in Skip Barber’s Going Faster book as what happens with “light throttle” in the context of a racing car. Neither of my cars has the combination of engine power, power delivery, suspension, tyres etc to really break away or even decrease turning radius at the rear under throttle in the dry unless you really unload the rear first. You move the grip front or rearward with your feet, and the car’s ability to change direction adjusts accordingly.
I also had a tuned Polo G40 at one point with a clutch-pack LSD out of one of the 90’s G40 Cup cars. Horrendously aggressive and chassis splitting. But that front-wheel drive car would actually decrease in turn radius as you applied power, and wash out wide as you lifted off, which I can’t make any sense of when I look back at it. Maybe it was some weird torque steer effect turning the actual steering geometry into the corner more. I had that car before I had LFS or any track experience so I doubt I was really at the limit, despite how terrifying it was.
I’d love it if the WIP tyre physics could be toggled on/off in a single player environment so we could give them a go. What’s being described—that feeling—likely really is bang on in that island take off circumstance and it’s just hard to put into words, but we’d all just recognise that feeling and agree it’s a step in the right direction.
Either way, look forward to seeing what you come up with on that side of things when you’re happy enough with them.