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trunk support stops for high downforce wings

i3igpete

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problem statement: high downforce wings (AJH, V1X) generate enough downforce to compress the adjustable support pads for the trunk. this causes the trunk to press into, and shatter, the tail lights from the top. if there is paint wearing away along the edge, it's making contact.

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Brian on the track supra facebook group (sorry don't know your name on here) noted that Verus provides a delrin support, but only 3 threads are engaged when mounted. while delrin is stiffer, there isn't enough thread engagement , and the trunk also begins to slide rearward on the pad due to delrin's low friction coefficient. Other wing vendors (adro, speed engineering, street hunter, etc) likely don't make enough downforce to even be aware of the problem needing a solution.

IMG_20250512_083752~2.jpg


brian pointed me to some solid rubber furniture feet:

https://www.amazon.com/gp/aw/d/B07L...JOHvgckdgm2lCNyEh6_aem_aVUGv4SjRPXhcluVnX-_Hw
Screenshot_2025-05-10-15-26-24-72_a23b203fd3aafc6dcb84e438dda678b6.jpg


and i added these aluminum spacers (1 per side) to spread the load so the threads aren't taking the entire load. this should also increase the stiffness even further.

https://www.ebay.com/itm/125206781352

ID: 3/8"
OD: 1"
length" 1/4"
IMG_20250510_151342~2.jpg


install pictures:
IMG_20250510_151134.jpg
IMG_20250510_151108.jpg


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i3igpete

i3igpete

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Addendum for those with the updated AJ Hartman reinforcement plate.

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The plate itself at about 1/8 inch of thickness to the trunk, so the 1/4 inch spacer will be too high. I recommend getting a stack of 1/16 inch spacers (again, 1 inch OD, 3/8 inch ID) and using 2.

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Since the bottom surface of the pad will now sit lower than the plastic cover trim, you will need to trim the rubber for it to rest flat on the spacers

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124Supra

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With those feet somehow my trunk can’t fully close, pls lmk if you have a solution? Should I cut the feet?
 
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i3igpete

i3igpete

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What wing are you using? Also, can you measure your rubber foot thickness? It's possible that the supplier on amazon changed and you'll need a different set of spacers
 

124Supra

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What wing are you using? Also, can you measure your rubber foot thickness? It's possible that the supplier on amazon changed and you'll need a different set of spacers
It’s not the spacer’s problem, the rubber is too thick, I will measure it later.
 
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i3igpete

i3igpete

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It’s not the spacer’s problem, the rubber is too thick, I will measure it later.
Not sure I follow why using a different spacer wouldn't change the total stackup height, will wait for picture
 

lucky phil

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Maybe a Supra GTS 2023 MT, Kia Stonic GT, Mazda CX5 GT SP
My Sydney composites wing came with a pretty neat solution for this.


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Nice engineering. I often wondered about generating aerodynamic downforce with a wing attached to flexible plastic bodywork/trunk hatch and what the implications were of doing that. Looks like here they have thought about it as well with some struts to transfer the aero force directly to the chassis where it should be going.
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