Cage question--(rear strut tower bar content)

#1

Question on rear strut tower braces for SpecE30

So, lets say we have this pad (pre cage tubes installed):
http://www.izzyscustomcages.com/images/CustCars/BMW/E30/SpecE30/KKSpecE30/P1010005.JPG

99.5" of pad, no side longer than 12"

Then we add the cage:
http://www.izzyscustomcages.com/images/CustCars/BMW/E30/SpecE30/KKSpecE30/P1010006.JPG

Now we get into the SpecE30 strut bar rule:

9.3.8.9. Any bolt-in or welded strut or shock tower brace is permitted, unless specified in these regulations. Attachment points are limited to the shock towers. This single bar is not a part of the car’s roll cage structure and is not bound by CCR section 15.6.

What I’m reading there is that the strut bar is specifically allowed, and not bound by any cage rules. What a potential customer is concerned about is the “limited to the shock towers” part should we go with the large pads of the type pictured (which hit the floorpan and go horizontally for 2.5").

Whle I have you scratching your head, if I had moved the bar up onto the cage downbars, would it be considered a strut bar if it’s not directly attached to the strut towers?

My thoughts: The bar would not be considered attached to something other than the tower just because the plate extends horizontally along the floor. And as to the second question, it would not be considered a strut bar. What do you guys think?

#2

When I read the rule I interpreted it to say that the cage cannot be welded to the strut tower… To be honest, even Jeff Ireland saw no benefit from it…

A cage should serve to protect the driver, and any unibody rienforcement should be shelved in favor of safety… Welding the tubes to the tire well next to the rear seat keeps the tubes shorter, stiffer and therefore marginally more safe.

Just my 2 cents… Ian and Seth Scally at Midnight Oil Motors in San Diego are go-to guys on cages for these cars, you might want to seek their opinion. They actually know what they are talking about. Better than listening to me guess my way through the question.

#3

I’m solely interested in the legality, not whether it is a good design.

#4

It looks like the tube across the top is a strut bar already. I goes to the same location on the other shock tower right? You want to add another tube?

#5

Not sure that would be legal. The mount isn’t to the shock tower, it is to something else attached to the shock tower.

The rules are such that they also include a host of “as long as it serves no other purpose” clauses. The “other purpose” does not have to be intended, it just has to be present.

I would think that this could be considered illegal. I concur with Mr. Gobey, I would contact seth at Midnight Oil Motors in San Diego, CA. I think he might have a more technical persepective.