Spool Diff

[gti_sdn]

Is the closest we can get to a spool diff to set the settings on the custom diff to Initial:60/Accel:60/Brake:60
Does this offer a full lock-up, or is there still the possibility of wheel speed differences across the axle?

 

[gti_sdn]

So i can confirm that setting all the values (Initial:60/Accel:60/Brake:60) on a Fully Customizable differential will make it act like a spool diff.

This first shot shows a car with its open differential, we can see the wheel speed difference across the rear axle during corner entry/mid/exit. Especially the inside wheel on exit.

The second shot shows a car with a customizable diff with the default settings, this shows the wheel speed across the rear axle a lot closer during the corner phases.

This last shot shows a car with the Customizable diff with the settings set to their maximum (Initial:60/Accel:60/Brake:60).
It clearly shows there is zero variation across the rear axle, acting exactly like a spool diff where there is a complete lock between left and right at all times.

 

[Greycap]

Excellent info! When I first saw the thread yesterday my idea was to dig into the wheel speed data but you got there yourself first.

Now, another question, since you have good software for it... how to make a Detroit locker for example. It would require 60 for acceleration and 5 for deceleration of course, but the initial value is a bit of a mystery. Logic says that 60 is always locked and 5 is open (well, as open as it can be) until either acceleration or deceleration occurs but you have the tools to see if that's the case.

 

[gti_sdn]

Excellent info! When I first saw the thread yesterday my idea was to dig into the wheel speed data but you got there yourself first.

Now, another question, since you have good software for it... how to make a Detroit locker for example. It would require 60 for acceleration and 5 for deceleration of course, but the initial value is a bit of a mystery. Logic says that 60 is always locked and 5 is open (well, as open as it can be) until either acceleration or deceleration occurs but you have the tools to see if that's the case.

If i have my theory right then the Detroit locker will only lock on throttle (acceleration), while all other states are open (deceleration/coast)
If this is correct then i would assume that the diff settings would have to be Initial:60/Accel:60/Brake:5
https://www.gran-turismo.com/au/gt7/manual/carsettings/02
Reading the manual the initial Torque is how responsive you want the locking up of the diff and with the Detroit it is instant from what i have read.
Now this instant lock up we want to happen only on acceleration so that has to be set to 60 as we know this is locked.
As you say with the customizable differential the lowest we can set the Brace sensitivity to is 5 (As open as possible).

Interested in what your application is as i assume this would make a car very nervous on the brakes and any acceleration mid corner would create a lot of understeer?

Older 60's and 70's Muscle car seems to be the only fit.