Physical mounting of an Amp in trunk

dickeypevo · Aug 19, 2007, 07:19 PM

I've got an amp set on a sheet of mdf, and I'm looking to mount it to the trunk. I know this is a stupid question, but what's the best way to mount it??
Do I just take some number 8 screws and power drill them on down? I've got a bad feeling that I'll hit something.

I'm putting the board flat in the trunk right behind the seats (all the way forward).

tia!

JohnnyBoy427 · Aug 19, 2007, 07:24 PM

Well that would mean you would drill right through your cars floor and your gas tank is directly under there. I dont know how much room there is between the floor and the gas tank but I personally wouldnt risk it. Im not much of an audio expert but most people mount their amps either under their front seats or on the seat back of your back seat if you want in in your trunk.

dickeypevo · Aug 19, 2007, 07:49 PM

Yeah that's what I figured.... just what i need, a nice explosion in the garage

I know I've seen several mounted back there so there's gotta be a way??

It seems like the foam on the back of the seat wouldn't hold much weight.... is there a structure accessible in there that may work?

housedj · Aug 19, 2007, 07:55 PM

i fabbed amp stands to resemble LCD monitors so that they weren't flat on the floor. i also removed the stock carpet & board & replaced w/MDF which is the same shape as the stock carpet. i then bolted my amps to the mdf. the sheet of mdf had to be used since i removed the spare & have an Alpine Type-X 12" back there. i had them under the seats originally but amps are normally designed to be mounted vertically & the sub amp would overheat even with my 1farad cap.

it's alot heavier back there now so i just run higher boost to make up for the weight

buddha1320 · Aug 19, 2007, 08:03 PM

im not sure how the ix looks but on the 8 they're are two thin bars that x on the back seat just remove the seats and you should see it screw the mdf on to that then you will have a sturdy enough place to mount it to and it will be towards the back of the trunk

JohnnyBoy427 · Aug 19, 2007, 08:04 PM

Quote:

Originally Posted by housedj

i fabbed amp stands to resemble LCD monitors so that they weren't flat on the floor. i also removed the stock carpet & board & replaced w/MDF which is the same shape as the stock carpet. i then bolted my amps to the mdf. the sheet of mdf had to be used since i removed the spare & have an Alpine Type-X 12" back there. i had them under the seats originally but amps are normally designed to be mounted vertically & the sub amp would overheat even with my 1farad cap.

it's alot heavier back there now so i just run higher boost to make up for the weight

Yup. You could just take that sheet of mdf you have it mounted on and slide it under that part of the carpet and then bolt the amp down to it through the carpet making it look clean IMO.

I am not sure if the evo has an X shaped bar going across the hole between the trunk and the seats but i have seen a lancer with that.

dickeypevo · Aug 19, 2007, 08:09 PM

Just checked, and yeah, there's a huge metal x right behind the seats that I can use and will work great.....

Thanks! This will be easier and cleaner now than drilling the floor- Think I'll use clamps or just drill through the X.

Thanks for the info- makes this stuff way easier when someone else has some advice.

fostytou · Aug 19, 2007, 08:10 PM

Quote:

Originally Posted by JohnnyBoy427

Yup. You could just take that sheet of mdf you have it mounted on and slide it under that part of the carpet and then bolt the amp down to it through the carpet making it look clean IMO.

I am not sure if the evo has an X shaped bar going across the hole between the trunk and the seats but i have seen a lancer with that.

Both the VIII and IX have this bar, Alot of people mount their subs to it... just watch out on spacing if you plan to get a rear strut tower bar.

mikesevo8 · Aug 19, 2007, 08:18 PM

Quote:

Originally Posted by dickeypevo

Just checked, and yeah, there's a huge metal x right behind the seats that I can use and will work great.....

Thanks! This will be easier and cleaner now than drilling the floor- Think I'll use clamps or just drill through the X.

Thanks for the info- makes this stuff way easier when someone else has some advice.

That's how I mounted mine ...
Use spacers to get a piece of plywood of MDF to butt up to the trunk lining.

JohnnyBoy427 · Aug 19, 2007, 08:19 PM

Quote:

Originally Posted by mikesevo8

That's how I mounted mine ...
Use spacers to get a piece of plywood of MDF to butt up to the trunk lining.

oh man that is extremely clean!

fenriq007 · Aug 19, 2007, 08:37 PM

Quote:

Originally Posted by mikesevo8

That's how I mounted mine ...
Use spacers to get a piece of plywood of MDF to butt up to the trunk lining.

Looks nice i was just wondering if you read your amp's instruction manual b4 you did that. I worked at a local install shop for about a year and one of the firsts things i was told was never to mount amps at more than an 90 degree angle. What you got there looks like a 105-110 degree angle. The problem is that most amps heat sinks are desing to disapate heat from the top so by doing more than 90 degrees the heat comes back down to the circuits which are now higher than the heat sink. You probably won't run into a problem right away but if you play the system hard you will over heat them faster.
Just my 2 cents no harm intended

mikesevo8 · Aug 19, 2007, 09:10 PM

I rarely run the system at anywhere near rated capacity. The amps are seldom, if ever, even warm to the touch.

boostinpsi · Aug 20, 2007, 03:43 PM

What type of screws would you recommend using to mount the MDF to the metal bars? Just self-tapping metal screws?

I would mount it under my seat because i carry things in my trunk quite often, but I'm afraid that it would get wet and fry the amp.

theCybe · Aug 20, 2007, 04:11 PM

Quote:

Originally Posted by fenriq007

I worked at a local install shop for about a year and one of the firsts things i was told was never to mount amps at more than an 90 degree angle. What you got there looks like a 105-110 degree angle. The problem is that most amps heat sinks are desing to disapate heat from the top so by doing more than 90 degrees the heat comes back down to the circuits which are now higher than the heat sink.

They're fine like that; The MOSFETs line both of the long sides of the amp, so even if you mount it at a perfect 90 degrees, there are FETs above the heatsink (at the 'bottom' of the amp, when mounted sideways.) Ideal position is flat, but really, the heatsinks on amps have much, much more surface area than they really need to cool those transistors anyway. If it's getting hot, it's either clipping or under impedance.

There are heatspreaders on the back side of the FETs also. Main issue with thermal dispersion in amps is that they're using that cheap-ass, thick thermal compound tape to mate the FETs to the heatsink, instead of something decent like Arctic Silver, or even a liquid silicon based goop.

Those amps will be fine.

Quote:

What type of screws would you recommend using to mount the MDF to the metal bars? Just self-tapping metal screws?

I'd drill the metal, then the MDF, and just sling some skinny bolts in there. Don't want that MDF rattling the metal