Rule 14.2 G (STX bodywork modification)

"Lower suspension braces must be attached to the lower suspension pickup point locations on the chassis within 2" in any direction of the actual suspension attachment to the chassis"

So, is this saying lower suspension braces that are added must be attached within 2" of any lower suspension pickup points (for example where the lower control arm bolts to the frame) and the other end of said braces must attach within 2" of another suspension pickup point?

OR

Does one end of an added brace get attached within 2" of a lower suspension pickup point and the other end can go anywhere.

OR

Can braces be added at all? By saying where lower suspension braces CAN be placed that does directly imply they can be used. Confusingly enough this rule is listed under the strut bar section. But a strut bar and a lower suspension brace are two different things, right?

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#20 Scion FR-S 6MT Powered by:
Great North Performance, Morine's Towing Performance & Off Road, Jani-King Canada and Blue Buzzard Performance Parts.

2013+14+15 Atlantic Sports Car Club Overall Autocross Champion
2013+14+15 Atlantic Region Motor Sports Overall Autocross Champion
2017-18 BAC Overall Rallycross Champion

I'd say just build this and let if fall into whatever class it may.

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1997 Talon TSi AWD
2008 EVO X MR

I'm working my way towards that, I'm just doing what I can before I go to forced induction and widebody kits (seriously). You could just give me a loan Scott and I'll do it all now?

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#20 Scion FR-S 6MT Powered by:
Great North Performance, Morine's Towing Performance & Off Road, Jani-King Canada and Blue Buzzard Performance Parts.

2013+14+15 Atlantic Sports Car Club Overall Autocross Champion
2013+14+15 Atlantic Region Motor Sports Overall Autocross Champion
2017-18 BAC Overall Rallycross Champion

Ha ha, I'm in the same boat. I have been slowly developing my car for 15 years and still have a long ways to go before I can say it's done (if that's even possible). It doesn't help our obsession when there are teams developing your same car in the World Time Attack, breaking new boundaries and demonstrating endless possibilities.

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1997 Talon TSi AWD
2008 EVO X MR

From what I gather, both ends of a bar will need be bolted within 2" of any suspension pickup point (so a bolt on the "shocks/struts, control arms, steering knuckles,
uprights, tie rods, live axle housings, etc., but not steering racks, subframes, halfshafts, etc."). However, if it's a triangular bar, the third (middle) bolt location must be on the firewall.

So yes you can have a bar. I think the only reason they would even state the 'within 2 inches' rule is for subframe/suspension geometries that are too complicated or not beneficial enough to use the stock bolt locations. So on the FRS subframe pic below, the 'gt-spec' bar at the top of the picture would be fine, it bolts both to the control arm and again within ~2 inches of the same bolts. As far as the 'strut bar rule is concerned, the one at the bottom of the picture wouldn't be allowed.

At the end of the day you can interpret the rules ay way you want. It's up to somebody else to have a problem with it and protest it. I had people come up to me at nationals and tell me they could protest me if I didn't replace my spare tire holddown bolt after I took the spare out. Lol

I would interpret that rule as it must be attached on both ends within 2" of the suspension pickups. 2 points of attachment only, like a strut bar. Triangulated (3pt) bars are only allowed if the car came that way from the factory.

The wording is a bit confusing, but it helps to reference 12.18:



So when they mention "Strut bar" they are covering any transverse suspension brace whether or not it actually mounts to a strut. SCCA

The top bar in Greg's post would probably not pass a protest, I doubt the upper set of bolts are within 2" of the control arm mounts.

I actually run a lower brace on my M3 similar to the lower one in that picture, but it is legal only because it came on M3 convertibles and I can make use of the update/backdate SP rules. Not ST legal.

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'99 BMW M3 / "Elvic"

Yeah I think 2" might have been a bit generous for those upper bolts. I wonder how much of a difference these would actually make on a car like the BRZ/FRZ. For comparison, people don't seem to think they have any benefit on the S2000, and that's a 15+ year old convertible design. Regardless, Devon, you should put one on and we'll put a strain gauge on it to see if actually does anything

Thanks Scott, that bit you posted really cleared that up for me.



Before I build anything I will be datalogging (via sensor and PC) the actual deflection to see if anything I can build would be worthwhile. On all the forums there is generally only estimates as to how much everything flexes, so I will be getting the community some hard data. If I can build my own brace(s) that work you may see it go into production for sale.

After bracing my own LCAs I remembered how much I love doing this stuff. Expect to see a lottttt more once I make the Jump to SM.

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#20 Scion FR-S 6MT Powered by:
Great North Performance, Morine's Towing Performance & Off Road, Jani-King Canada and Blue Buzzard Performance Parts.

2013+14+15 Atlantic Sports Car Club Overall Autocross Champion
2013+14+15 Atlantic Region Motor Sports Overall Autocross Champion
2017-18 BAC Overall Rallycross Champion