The problem:
Tesla's seats have a squab (base) that is too short (in front-to-back length, not height) to properly support the thighs of some above-average-height drivers, depending on how they're proportioned. This problem exists in many cars, but some of them allow a range of adjustment to the squab tilt angle that can help compensate for the lack of support. Tesla's design choice, at least for Model 3, doesn't allow significant front-high tilt of the squab, and the design of the seat adjusters also means that raising the whole seat rotates it forward, which removes what little tilt exists.
Proposal:
Force the front of the seat higher, thereby moving my center of gravity further back and away from the front edge of the seats
Proposed method:
The basic theory comes down to "add washers between the front of the seat tracks and the floor of the vehicle".
Points of consideration:
Lifting the front of the seat tracks will change the geometry of the seat relative to the vehicle, and the forces that are applied to the seat in all situations. It's essential to do the math and make sure that the force applied to each of the four bolts securing the seat rails to the vehicle is not changed to an extent that it becomes unsafe in an accident.
Additionally, adding materials will cause the tracks to no longer sit flat on the floor of the vehicle. It will be necessary to use leveling washers to accommodate the angle that will be created, and use longer bolts to account for the additional hardware.
I haven't found leveling washers in an M10 size that will compensate for more than a 3° deviation, and the ~14.5" length between the existing bolts means that I'm limited to roughly an additional .75" lift on the front edge of the seat. I don't yet know if that's enough to make a significant difference. I'll likely just unbolt the seat from the tracks and shim the front just to sit in the garage for a while and see if it's worthwhile to continue the effort.
Lastly, I haven't measured to see how far past the bolt holes the tracks extend. It's possible that I might have to lift the front AND back of the seats (just lifting the front further) to avoid bending the tracks due to the angle. Every mm higher the seat goes, the more the force changes on the bolts (and washers), though.
Alternatives:
It seems conceptually possible that I should be able to fabricate something to make the changes necessary in the seat adjuster hardware/mounting, but I can't get a good enough look at the underside of the seat while the seat is in the car and I'm not quite bored enough to pull the seat out just to get a good look.
Anyone done this sort of thing before and/or have constructive input? If you're happy with the seats already, I'm happy for you and I understand that you don't think these sort of changes are necessary.
Tesla's seats have a squab (base) that is too short (in front-to-back length, not height) to properly support the thighs of some above-average-height drivers, depending on how they're proportioned. This problem exists in many cars, but some of them allow a range of adjustment to the squab tilt angle that can help compensate for the lack of support. Tesla's design choice, at least for Model 3, doesn't allow significant front-high tilt of the squab, and the design of the seat adjusters also means that raising the whole seat rotates it forward, which removes what little tilt exists.
Proposal:
Force the front of the seat higher, thereby moving my center of gravity further back and away from the front edge of the seats
Proposed method:
The basic theory comes down to "add washers between the front of the seat tracks and the floor of the vehicle".
Points of consideration:
Lifting the front of the seat tracks will change the geometry of the seat relative to the vehicle, and the forces that are applied to the seat in all situations. It's essential to do the math and make sure that the force applied to each of the four bolts securing the seat rails to the vehicle is not changed to an extent that it becomes unsafe in an accident.
Additionally, adding materials will cause the tracks to no longer sit flat on the floor of the vehicle. It will be necessary to use leveling washers to accommodate the angle that will be created, and use longer bolts to account for the additional hardware.
I haven't found leveling washers in an M10 size that will compensate for more than a 3° deviation, and the ~14.5" length between the existing bolts means that I'm limited to roughly an additional .75" lift on the front edge of the seat. I don't yet know if that's enough to make a significant difference. I'll likely just unbolt the seat from the tracks and shim the front just to sit in the garage for a while and see if it's worthwhile to continue the effort.
Lastly, I haven't measured to see how far past the bolt holes the tracks extend. It's possible that I might have to lift the front AND back of the seats (just lifting the front further) to avoid bending the tracks due to the angle. Every mm higher the seat goes, the more the force changes on the bolts (and washers), though.
Alternatives:
It seems conceptually possible that I should be able to fabricate something to make the changes necessary in the seat adjuster hardware/mounting, but I can't get a good enough look at the underside of the seat while the seat is in the car and I'm not quite bored enough to pull the seat out just to get a good look.
Anyone done this sort of thing before and/or have constructive input? If you're happy with the seats already, I'm happy for you and I understand that you don't think these sort of changes are necessary.
