Screws in the trunk?

[bogey555]

Hello guys,

I placed a flat subwoofer in the trunk of my octy II . (see link)

TS-WX77A Pioneer Car Entertainment

I attached it for the moment with the nethooks in the back but I want to screw it to the floor of the boot against the rear seats.

Does anybody now how close the petrol tank is below the trunk, and if it's possible to use selftapping screws?

Thanks in advance

[encephalopathy]

what about something along the lines of 3M double sided velcro to hold it in place rather than screwing it in. you can get rolls of this ~5cm width - coupleo f strips of this and thats a pretty substantial amount of grip for you

[Birdwell L&K]

Why not no nails it, if you screw to the boot floor would it not invalidate your warrenty.

[bogey555]

what about something along the lines of 3M double sided velcro to hold it in place rather than screwing it in. you can get rolls of this ~5cm width - coupleo f strips of this and thats a pretty substantial amount of grip for you

Could be something, but do you think it can withstand the extreme vibrations? For a small box like it is I was pretty surprized about the bass it packs. That was the main reason why I wanted to screw it down, to let it have real contact with the chassis.

[bogey555]

Why not no nails it, if you screw to the boot floor would it not invalidate your warrenty.

I don't know if this infects the warranty.

[Birdwell L&K]

Thought it might affect the body work warranty.

[cheezemonkhai]

Industrial velcro left to cure properly will do just fine.

You'll need to support it on the base and the back or side of the sub box, but bearing in mind what I've hung off that stuff I doubt it's going anywhere.

Velcro by it's nature doesn't come undone by vibration, however screws would.

[bogey555]

Industrial velcro left to cure properly will do just fine.

You'll need to support it on the base and the back or side of the sub box, but bearing in mind what I've hung off that stuff I doubt it's going anywhere.

Velcro by it's nature doesn't come undone by vibration, however screws would.

Thanks

Isn't the velcro going to absorb the vibrations?

[Birdwell L&K]

I would have thought so, but is boot floor totally flat?

[bogey555]

I would have thought so, but is boot floor totally flat?

Very good question, I haven't even looked at that. I presumed that it was as easy as drilling holes and attaching the thing with selftapping screws.

The sub comes with plastic bars that need to be screwed and belts to attach the sub to these plastics.

[Birdwell L&K]

Do you have the false floor fitted?

[bogey555]

Do you have the false floor fitted?

No, so I can't attach it to that. Anyway I presume that attaching it to a false floor wood give bad resonance.

Even now, I have strapped it down with belts on the side hooks in the back it lets the trunk vibrates a lot. I will certainly need some damping material in some places.

[sebulbus]

The tank's beneath the back seat somewhere.

This being said, I'd epoxy some nuts to the metal, then cut the carpet or pierce it with the screw directly. No pierced metal => no warranty issues.

[sdenny]

Why not no nails it, if you screw to the boot floor would it not invalidate your warrenty.

I've used no nails before to glue wood to the boot to mount things on. Worked very well

[bogey555]

The tank's beneath the back seat somewhere.

This being said, I'd epoxy some nuts to the metal, then cut the carpet or pierce it with the screw directly. No pierced metal => no warranty issues.

Thats a very good idea, can you elaborate a bit further on how to do it exactly, I never used epoxy before. Is there any brand I should consider?

Is it strong enough to withstand the vibrations?

[bogey555]

I've used no nails before to glue wood to the boot to mount things on. Worked very well

So this glue is supposed to be strong enough?

[sdenny]

So this glue is supposed to be strong enough?

I had a vertical mounted cd changer that had you be mounted on a corregated part on a boot floor. The coregations were about 5-10mm (I forget - it was years ago). I just applied a liberal amount of nonails to a piece of wood the same size as the changer foot print and pressed hard, moving the wood arround a bit to make sure I had good contact (like you do with tiling, if you've ever do that).

The screwed the brackets to that. I sold the piece of wood with the car as I couldn't get it out.

I reckon if you use a decent size piece, it'll work well.

[Gizmo]

Before doing any of the above think of the mess it will leave if you intend to take the sub out when you sell the car.

Personally i would bolt it in using either stainless or zinc plated bolts, i would also paint the hole in the bodywork to stop the holes from rusting, then before fitting the bolts place a small amount of silicon sealant round the hole to ensure they are water tight.

This way when you remove the sub, just replace the bolts back in the holes.

[bogey555]

Before doing any of the above think of the mess it will leave if you intend to take the sub out when you sell the car.

Personally i would bolt it in using either stainless or zinc plated bolts, i would also paint the hole in the bodywork to stop the holes from rusting, then before fitting the bolts place a small amount of silicon sealant round the hole to ensure they are water tight.

This way when you remove the sub, just replace the bolts back in the holes.

You have a point there, but how do you get the bolts inside? You need to drill holes in the floor, what leaves me with my initial question, what about the diesel reservoir? And if you use bolts don't you need access from under the car?

[Gizmo]

You would of course need assistance to bolt them in, the fuel tank is located under the rear seat so that will not be a problem.

Before any holes are drilled into a car the underside of the car should be inspected to make sure there are no pipes, filters, tanks etc under where you are about to drill, also remember that if you drill into a box section (chassis rail etc) then you are going to have to use screws (not an ideal or correct way - IMO) as you will not be able to get the nuts on.

Remember:

Prior Planning & Preparation Prevents P155 Poor Performance

[bogey555]

Thanks for all your replies guys,

I will pass by the garage and ask them for some assistance in drilling the holes. I think the bolt system of Gizmo68 gives the best attachement to the chassis. I guess I will bolt, sort of holders in the trunk and then pass a belt trough them. I will remake the plastic ones delivered with the kit in stainless steel.

[cheezemonkhai]

Thanks

Isn't the velcro going to absorb the vibrations?

That isn't a bad thing even if it did (which it won't do in a huge amount)

You don't want to vibrate the car body, you want to vibrate the air in the car using the cone of the sub. The cone and any ports will do this just fine.

If you're bothered I'd cut a few flaps in the carpet and use the industrial velcro directly to the metal for a better bond, then put the hooks on the sub side and the loops on the other side. To be fair the hook side sticks pretty well to the carpet anyway, so as long as the carpet wasn't moving you might be ok with that.

[sebulbus]

Thats a very good idea, can you elaborate a bit further on how to do it exactly, I never used epoxy before. Is there any brand I should consider?

Is it strong enough to withstand the vibrations?

Pierce the carpet in the places intended for the holes and with a sharpie mark the places where the nuts will go.

Then pull the carpet apart a bit, get some clean, degreased nuts, and also degrease the spot. Put any decent bicomponent adhesive on the nut and body per the package instructions.

Put carpet back and put the screws through the carpet, threading them in the nuts and through some eyelets of some kind your sub should have. Otherwise just fashion some straps to go over/around it. The carpet will seat very neatly around the screws.

I use Bison stuff for everything from repairing pipe work round the house to fixing a friend's gas tank. Works very very well and only costs 1-2 Euros a piece.

Time to take it all off? Get a sharp chisel, lay it flat against the body and strike briefly, the epoxy should fly off leaving the body clean. Put carpet back.

[bogey555]

That isn't a bad thing even if it did (which it won't do in a huge amount)

You don't want to vibrate the car body, you want to vibrate the air in the car using the cone of the sub. The cone and any ports will do this just fine.

If you're bothered I'd cut a few flaps in the carpet and use the industrial velcro directly to the metal for a better bond, then put the hooks on the sub side and the loops on the other side. To be fair the hook side sticks pretty well to the carpet anyway, so as long as the carpet wasn't moving you might be ok with that.

You have a point, velcro is easy to use but I have used it a lot at work and if you apply it generously it sticks better then glue;)

If you need to take the sub out for any reason you need a crowbar to get it out:D

I didn't know it was only the air displacement that was important, I thought that the vibes should also be passed on to the chassis.

A few weeks ago I listend to a Hertz democar and there they placed a sub in the spare tyre hole. The guy told me the reason why it sounded so great was that it was fixed to the chassis. :confused:

Anyway I will go over to the dealer and see if it is easy to get bolts trough the trunk as Gizmo68 says and if it's to much hassle I will check the Velcro solution , but maybe try it on the carpet first.

[cheezemonkhai]

Well the less the box can move, the more forge the air in the box and the boot will be moved.

If you have too high a sound pressure level you will start making the boot and various parts of the car vibrate. This will sound sh*te to you and make the rest of the world p*ss themselves with laughter as they drive past.

Edited 7 October, 2008 by cheezemonkhai