Flat Floors

[Halcyon925]

In real life the floors help. In GT it's harder to say.

Rear downforce helps all cars, including FF. All four tires are used for cornering and FF's are prone to lift off oversteer because of the lack of weight on the back. Rear downforce will prevent the back end from sliding out during a sudden release of the throttle at high speed and allows you to run more front downforce.

A full flat underbody panel also doesn't produce downforce solely at the rear. It's produced all along the floor. There are low pressure peaks though, usually the splitter and the diffuser entrance. (blue in the image below)

The relative strengths of the peaks can move the center of pressure forward or backward and change grip balance.

This could all mean nothing in GT though. We already know floors incorrectly produce drag, so they may be modeled poorly in other ways. The fact that they add drag is not only bad for top speed, but potentially also for handling. It depends on where the drag force is compared to the center of mass.

Race cars have wings mounted low even though the air is cleaner up high because the drag on a wing produces a moment that lifts the front wheels. If the GT6 flat floor adds drag above the center of mass of the car, you will end up losing some front grip (but probably not enough to negate the benefits of downforce). This can be made up for with some suspension tuning to put less weight on the front tires.

Which ever way the GT floor works, all cars should see a benefit, at least when tuned properly.

Thanks a lot for your input. If that is true with the loss of tire grip in the front, then I should consider removing flat floors off most of my cars; although, this needs to be proven for me, and possibly others, to remove our flat floors.

 

[Otaliema]

Thanks a lot for your input. If that is true with the loss of tire grip in the front, then I should consider removing flat floors off most of my cars; although, this needs to be proven for me, and possibly others, to remove our flat floors.

The pp hit on the cars from the flat floor is pretty serous so you will notice an improvement in lap times unless your running maxed out cars.
You will notice a reduction in turning ability w/o the flat floor but better acceleration.
Even with the "reduced" grip on the tires you are getting an even downforce fiction across the length of the car and there for better turning and braking.

 

[Halcyon925]

The pp hit on the cars from the flat floor is pretty serous so you will notice an improvement in lap times unless your running maxed out cars.
You will notice a reduction in turning ability w/o the flat floor but better acceleration.
Even with the "reduced" grip on the tires you are getting an even downforce fiction across the length of the car and there for better turning and braking.

I wouldn't say that it would give you better turning or braking, but it would just make the car more stable during those scenarios. For example, if your car slides in the rear when hard braking without a flat floor, the car will have better traction than it would with a flat floor; but at the same time, it would have worse stability when you brake without a flat floor.

For cars that drive well without sliding, then a flat floor is not needed since it would make traction worse. But for cars that slide, like any MR or RR, then a flat floor will be needed since these cars need more stability; but not as much as they need traction.