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Transmission Tunnel Modification Clarification


weenrock
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Plain question, what is the Transmission Tunnel defined as regarding rule 6.2.1 5)?

https://nasa-assets.s3.amazonaws.com/document/document/23457/ST1-4___SU_Rules_2022--v16.1--12-1-21.pdf

"Other than the listed exceptions, every Production vehicle must retain its unmodified:
1) OEM frame rails/rear frame cross beam, and/or Unibody, and Sub-frames/suspension
cross-members (in their OEM locations).
2) Strut/shock towers
3) Inner/inboard side of the fender wells (any non-horizontal aspect)
4) Rocker Panels
5) Transmission tunnel

5) The transmission tunnel may be modified for the purpose of installing a competition driver seat. The floor pan must remain in its original position."

 

In an S2000, there are two pieces. 1) The tunnel that is part of the unibody and floor and the 2) bracing that is spot welded on top of the transmission tunnel to provide rigidity. This adds weight and is not necessary with a cage. The space the the transmission fits within will have an unmodified shape, only the bracing would be removed, which I argue is not modifying the tunnel itself, if removed.

With bracing: 97056d1501325081-insomnia-build-lightwei

Bracing removed: attachment.php?attachmentid=14057

 

Is there an official ruling on this situation?

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2 hours ago, weenrock said:

Plain question, what is the Transmission Tunnel defined as regarding rule 6.2.1 5)?

https://nasa-assets.s3.amazonaws.com/document/document/23457/ST1-4___SU_Rules_2022--v16.1--12-1-21.pdf

"Other than the listed exceptions, every Production vehicle must retain its unmodified:
1) OEM frame rails/rear frame cross beam, and/or Unibody, and Sub-frames/suspension
cross-members (in their OEM locations).
2) Strut/shock towers
3) Inner/inboard side of the fender wells (any non-horizontal aspect)
4) Rocker Panels
5) Transmission tunnel

5) The transmission tunnel may be modified for the purpose of installing a competition driver seat. The floor pan must remain in its original position."

 

In an S2000, there are two pieces. 1) The tunnel that is part of the unibody and floor and the 2) bracing that is spot welded on top of the transmission tunnel to provide rigidity. This adds weight and is not necessary with a cage. The space the the transmission fits within will have an unmodified shape, only the bracing would be removed, which I argue is not modifying the tunnel itself, if removed.

With bracing: 97056d1501325081-insomnia-build-lightwei

Bracing removed: attachment.php?attachmentid=14057

 

Is there an official ruling on this situation?

The "bracing" appears to be welded to the trans tunnel and to the rear floor by the manufacturer, which would arguably make it part of the unibody.  There is no rule that differentiates parts of the unibody that are spot welded in place versus seam welded.  I'm not sure where this exactly ends if the rule states to leave the unibody unmodified, but then parts that are welded in constructing the unibody are being modified and/or taken off.  We would be willing to hear arguments either way, but a Race Director could end up with this as a protest, and just make his/her own ruling anyway unless there was a rule revision that clearly permitted removal of spot welded parts which seems like a Pandora's box. 

Next question, who's car is in the bottom picture?  Is it a case of better to ask forgiveness than permission (or rather, risk losing a protest and get DQ'd and have a car that is no longer legal for the class)?

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On 1/13/2022 at 6:08 PM, Greg G. said:

The "bracing" appears to be welded to the trans tunnel and to the rear floor by the manufacturer, which would arguably make it part of the unibody.  There is no rule that differentiates parts of the unibody that are spot welded in place versus seam welded.  I'm not sure where this exactly ends if the rule states to leave the unibody unmodified, but then parts that are welded in constructing the unibody are being modified and/or taken off.  We would be willing to hear arguments either way, but a Race Director could end up with this as a protest, and just make his/her own ruling anyway unless there was a rule revision that clearly permitted removal of spot welded parts which seems like a Pandora's box. 

Next question, who's car is in the bottom picture?  Is it a case of better to ask forgiveness than permission (or rather, risk losing a protest and get DQ'd and have a car that is no longer legal for the class)?

Thanks for the reply Greg!

These were just example photos I found of other racers who have/have not removed the bracing. The bracing of my trans tunnel are still intact. I am dropping off my car to the cage builder this coming week and I am making all of my modifications before they build the cage. I also see your point that someone could still protest even while I tried to operate in good faith. It would be easier to remove it all together to allow for easier fitment of a seat, but I'll just notch it for now like others have done. See below image.

The reason for my question is trying to keep my S2000 in TT4. The changes for 2022 TT4 are very much welcomed to allow for more cars to fit and increase competitiveness. My S2000 sits at 219avg HP/2550LBS min weight and adding a cage was important this year for safety. I have one the lightest S2000s in TT4 from 2021 and removing weight to offset the cage is not feasible so adding power would require an engine swap or FI. Or, move back to TT5. Arguably, TT4 is more fun.

Cheers!

AM-JKLUFuGC98cqH_agnV0bBGRxD4jGFCsu95Qqt

 

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