Just thinking about it, do you think there would be any benifit to filling the front strut brace with expanding foam? maybe make it a little stiffer?

 

Nope, strut bars are not even really needed on the RX-8. Strut braces are designed for macpherson strut suspension systems which the RX-8 does not have. I'm not sure why the RX-8 has one.

 

It may not be needed for autoX, it surely is on a track
Yamaguchi's rx8 book says it's meant to be there and renderings of the stock chassis show it too.
Filling the stock upper brace would be a waste of time and money though. Its shape makes it very hard to fill and the results would be negligible. I'd either keep the oe one or buy something used from the fs section.

 

Maybe Chassis Rigidity for the front of the car. Help prevent flexing in the upper part of the engine compartment is my guess? oh what He^ said.. lol

 

What about filling the stock engine cradle?

 

The engine cradle on the Shinka, 40th Anniversary and the R3's are urethane foam filled. I don't think that is available at your local Home Depot. If it is and it was used, I don't know how much it work.

 

I'll have to take a look at the Yamaguchi book and see what it says. I did not have mine on for a long time and didn't notice a difference. I do like strut bars though, I have three of them

 

With three of them, it must be really rigid.
I have the MS bar for the looks and the brake brace.

 

The oe subframes can be reinforced by seam welding them after adding 2 layers (1 up, 1 down) of sheet metal (2mm thick) to the border\perimeter.
Looks ugly as sin afterwards but weighs considerably less than autoexe braces.

 

Just for looks brah, just for looks...