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ST1 rule - replacing an OEM frame brace with a bolt-in tube


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I already sent an email to Greg with this question, but wanted to post it here to maybe get a few other suggestions or opinions.

The issue:  I have a Honda S2000 being prepped for ST1.  There is a horizontal brace that ties the front frame rails together in the engine bay, right in front of the engine.  It is a boxed sheet metal structure, welded to the frame.  I’ve found a picture online and attached it, highlighting the brace in yellow.  The Honda parts catalog calls this a “front Crossmember” (but not a suspension cross member)

The purpose of replacing the brace with a bolt-in bar is to make removing the engine / transmission much easier.

the goal is the remain classified as a production car in ST1.

the rules I can find that address this:

6.1.7 Tube-frame chassis conversion (partial or complete) is permitted in ST1, ST2, and ST3, but all tube-frame chassis conversion vehicles will be assessed the Modification Factor for “Non-Production” vehicles, and subsequently, none of the other rules specifically for “Production Vehicles Only” will apply (6.2). If a vehicle cannot be driven safely, at full speed, with any of the added tubes removed, it is considered a tube-frame chassis conversion.

6.2.1 Chassis and Body Modifications to Production Vehicles
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
6) Floor pan
7) Windshield frame location

My conclusions and thoughts fron these two rules:

- 6.1.7 permits minor tube frame modifcations while retaining production car status, and claims as long as the tubes can be removed and you still drive the car, you can avoid being labled as a tube frame conversion.  This rule supports my modification, as many people do drive S2000’s with this brace removed.

6.2.1 - requires an unmodifed unibody.  none of the other components mentioned in 6.2.1 address this brace, but unibody could.

So basically 6.1.7 seems to be written specifically for these kinds of modifcations but 6.2.1 seems to block any attempt at replacing anything with a tube.




Edited by Greyout81
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I don't have an e-mail about this in my inbox, so it may have been lost in the spam folder or lost otherwise.  This would be a specific case that is not common with most other models, and from a rules intent standpoint, would have fallen under this, if the wording had been "non-suspension cross-members other than the rear frame cross beam":

1e) Modifications of transmission cross-members and mounts, differential mounts, and radiator core supports are permitted.

Shoot me another e-mail with this all copied and a formal request for a rule change consideration.  We might be able to change the wording to this or something like it, in the upcoming revision:

1e) Modifications of non-subframe/suspension cross-members (other than the rear frame cross beam), transmission mounts, differential mounts, and radiator core supports are permitted.

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