TT4 Chassis mount rear wing allowed?

[weenrock]

The rules for tt4 are unclear whether a chassis mounted wing violates the 6.4.2-4 rule:

 

6.4.2 ST4 Aerodynamic Modification Restrictions and Limitations If not using the BTM Aero Modification Factor, aerodynamic parts/devices/aides shall be limited in ST4 to the following: 4) Single rear wing or spoiler that does not exceed a height of 8” above the roof line, or width greater than the vehicle’s body width, or end plates with area greater than 144 square inches each, or 12” protrusion from the rear of the vehicle. Body width does not include flared fenders, mirrors, splitter, door handles. 

Is the 12" protrusion referring to the end plates or the wing position in relation to the rear of the vehicle?

For reference, I am looking at this chassis mounted wing so I can avoid having my trunk deformed and changing the AoA. This is a common issue for S2000s.

 

Cheers!
Eric

[427R]

Pretty sure the below rule can be applied to rear wings as well, even though nothing in the rules specifically address this.  A question was raised about a year ago on how far diffusers could extend/protrude past outermost edge of bumper and Greg G., responded, 12" was about it.  So, it makes sense that wings are limited to the same 12".

6.1.1 Active aerodynamic devices and/or modifications (including, but not limited to,
computerized, cockpit adjustable, self-adjusting, and OEM) are not permitted. Aerodynamic
devices and/or modifications may not protrude more than six (6”) inches from the vertical plane
from the ground to the widest part of the right and left sides of the vehicle’s body. Front
wing/spoiler/foil/splitter may not protrude more than 12 inches in front of the outermost edge of
the front bodywork/fascia, and may not be higher than the lowest part of the vehicle’s hood.

[weenrock]

I thought the same thing. I'd assume the wing foil can't be more than 12 inches back, but does it also apply to the mount itself knowing the mount doesn't create an aero advantage? The issue is with s2000s and trunk deformation. They often deform under downforce and its hard to reinforce the trunk. So, a chassis mount can avoid it. It decided to go another route entirely to avoid any rule issues. 

On 1/18/2021 at 2:42 PM, 427R said:

Pretty sure the below rule can be applied to rear wings as well, even though nothing in the rules specifically address this.  A question was raised about a year ago on how far diffusers could extend/protrude past outermost edge of bumper and Greg G., responded, 12" was about it.  So, it makes sense that wings are limited to the same 12".

6.1.1 Active aerodynamic devices and/or modifications (including, but not limited to,
computerized, cockpit adjustable, self-adjusting, and OEM) are not permitted. Aerodynamic
devices and/or modifications may not protrude more than six (6”) inches from the vertical plane
from the ground to the widest part of the right and left sides of the vehicle’s body. Front
wing/spoiler/foil/splitter may not protrude more than 12 inches in front of the outermost edge of
the front bodywork/fascia, and may not be higher than the lowest part of the vehicle’s hood.

 

[Flip]

Nine Lives has a (much better looking, imo ?) chassis mount the goes through the trunk rather than mounting off the back (ie: Battle Aero style). I had concerns with water getting into the trunk since I have an open trailer, so I went with the trunk mount and did the CR reinforcement. I'm still waiting on my wang to ship, but the trunk is much more solid after adding the CR parts. 

They also have a swan neck version, but not sure how far that protrudes from the bumper line.