Foaming doors for spl competition

[shizzzon 461]

I just got done applying SPL tiles to the outer shell and inner frame of the door.

The door itself sounds a lot better but now i would like to prevent the door from flexing within reason.

I have the idea of rolling the window all the way down so i can then make a form with cardboard in between the window and the outer shell of the door, then just fill it in with expanding foam.

I'll do probably about 80% of the outer shell so it doesn't interfere with anything on the far ends of the door such as wiring or door locks, etc...

As far as i know, besides that, i just gotta make sure i do not block the drain holes on the bottom of the door and i should be good, right?

i've never attempted to brace the outer shell so severily before so i need to make sure i'm not about to make a mistake.

[///M5 2,833]

Not sure you've thought this through

[TRP 42]

I am not sure if it would work as well as you are hoping, but then again i have never done it myself!!! If you could some how block the foam from not coming past where the window is and only do the outer skin, i dont know why it wouldnt work? But GL anyways!!

[BanginGMC 23]

Did you think about using The Second Skin Sludge

[shizzzon 461]

actually, spl sludge would be for my application but it's not marketed yet and i dont even know if i want any.

[shizzzon 461]

i guess u guys are implying that placing foam to the door without any back pressure(no chamber to fill) that it will basically do nothing? Is that what you guys are getting at?

[iamamp3pimp 34]

I just got done applying SPL tiles to the outer shell and inner frame of the door.

The door itself sounds a lot better but now i would like to prevent the door from flexing within reason.

I have the idea of rolling the window all the way down so i can then make a form with cardboard in between the window and the outer shell of the door, then just fill it in with expanding foam.

I'll do probably about 80% of the outer shell so it doesn't interfere with anything on the far ends of the door such as wiring or door locks, etc...

As far as i know, besides that, i just gotta make sure i do not block the drain holes on the bottom of the door and i should be good, right?

i've never attempted to brace the outer shell so severily before so i need to make sure i'm not about to make a mistake.

the expanding foam will move your cardboard around, and then you will lose use of the window anyway.

id recommend foaming inbetween the brace that is in (most) doors that runs lengthwide with the car, and the outer skin.

another thing the foam can do is if you use too much, it can distort the shape of the outer skin of the vehicle by either expanding too much, or expanding to the form of the metal, and then shrinking after it adheres to the skin......pulling it down from the inside.

[iamamp3pimp 34]

i guess u guys are implying that placing foam to the door without any back pressure(no chamber to fill)

you dont need to create a pressurized cha,mber so to speak...but i do see how trying to make it dense would help. Edited April 2, 2010 by iamamp3pimp

[Impious 1,476]

Are you trying to strengthen the door from the pressure of speakers in your door, or from your subwoofers?

[shizzzon 461]

the subwoofers.

I need it rigid, but within reason... This is my daily driver so i can't permanently do something to the door that would render normal functionality of the door useless.

[outhopu 70]

You could add some more bracing to the door if you have a big enough opening to get it in there. There are panel glues out there that are strong enough that they use them to glue door hinges on. A good autobody supply place should be able to help you select the right one. Then you could bond a piece of steel tubing to the skin. A piece long enough to tie into the front and rear of the door frame would be ideal but may not be practical to fit into the door. Just an idea I've been kicking around for something I'm working on.

[///M5 2,833]

Did you think about using The Second Skin Sludge

I hope not, that is basically crap.

actually, spl sludge would be for my application but it's not marketed yet and i dont even know if i want any.

And that would be even worse.

the subwoofers.

I need it rigid, but within reason... This is my daily driver so i can't permanently do something to the door that would render normal functionality of the door useless.

I think there is a bit of a misconception problem here.

[Randal Johnson 544]

I wouldn't do this to a daily driver, but i've seen this in competion vehicles.

Take the door pannels off and replace them with a sheet of 3/4 mdf cut to the shape of the door pannel. I was told it helped sealing the cabin better.

The truck was a 1500 chevy single cab with the wall cut with 2 RD audio 15s with a Rd Audio D9. 4 batteries.

154 db at 54 htz every time it went thru the lanes.

I know this will not help you with you specific problem but possibly, maybe give you some ideas.

[shizzzon 461]

i can always remove it.

I am allowed to build out 0.75" from the door and leave the panel off so it is legal.

I have been thinkin about doin that... just using a LOT of duct tape every time i install it so i don't have to clean up silicone every time.

[iamamp3pimp 34]

i dont think it would be worth it.

[Randal Johnson 544]

I've seen one suburbon with the roof(headliner) changed to 3/4 mdf, doors, and the floor ...

Guess you got to do what it takes to put up a high number.

I'm not sure about the others, but USACI has limitations on battery power, alternators, and number of amplifiers per class.

Depending on what class you run in, You have to modify your vehicle to keep up with (strictly)competition vehicles.

We seen a guy the other day runing 0 - 1000 modified class hit 163 db at 57 htz. Thats insane ...

[mlstrass 1]

just deaden both sides of the inner door skin and also the back of the door panel. Should be enough for a 160 vehicle. After that most guys fill them with sand/cement which isn't very practical for a daily driver...

Also dbDrag lifted the limit on layers of deadener, so you can go crazy if you want. But air tight should be more important then some flex, assuming you meter sealed up. If it's USACI or MidWestSPL and you can have a door open then I wouldn't worry about it...

[SUNDOWN/FI BEATIN 0]

i wouldnt go on and do that... the way im reading the rules for MECA you can do a buildout up to 3/4'' thick... however sprafoam, resins and stuff are done by the general deadening rules which isnt very thick..