spray foam will kill the flex if the roof is broke off from the supports like mine was. deadener will kill the rattles on the outside too. My roof use to flex just as much untill i put 5 layers on the roof and foam in between every brace, nice and quiet and alot less flex.

 

Spray foam should work..depending on what density/concentration you use. It hardens up pretty well, and will fill a void between anything. Plus it acts as insulation so it cuts down on noise.

 

you are talking about 2 different things here. Flexing and rattling are not the same. Your roof can flex all to hell and not have any rattles. Same with the vise versa. Foam is a sound absorber. It does not help with flexing. Deading helps with some flexing since all it does is add weight to the surface it is applied to which lowers the resonant frequency. The only way to absolutely stop any flexing is to reinforce the surface with material strong enough to widthstand the sound waves and forces of air which is causing the surface to move.

 

well apparently spray foam reenforces it enough to stop flexing, my roof flexed just like blazinlouds did if not more before I foamed it, now its alot less flex. the deadener did nothing for the flex, the foam cured it.

 

lol the video does no justice on my $160 camera. its pretty violent in person.

 

Thanks! I just sold the flipout and sub, so my truck is back to stock. But good news! I've got a buddy with a Charger who has 2 15" Alpine Type R's in a 36x32 ported box with a Capacitor that he'd sell me for $400 (which is what the box cost alone since it was custom made). I've got a spare Kenwood deck laying around so this may be my weekend project.. I'll post pics if it happens!

 

Go for it! With all you are saving on gas over there, it practically buys itself!

 

Hahahah good point :P I'm installing my deck tomm and taking the subs on a "test drive".. will take pics!