I am once again, following in the footsteps of Fierosound and installing subwoofers in the firewall of my new Fiero. Some of you may remember seeing the pic of the first sub I did:

This sub was constructed of wood. I had a hard time sealing the box and consequently, the bass is not as good as it could be. I had this one installed in my 86 GT and I only did it on the passenger side.

I am now installing subs in my new 87 GT. This time I am putting one on both the pass side and the driver's side. And I will be making them out of fiberglass.

I will try to take you through the step by step processes. The pics are being stored on my own server (to save bandwidth) and I will make a website with as much of the info as I can when I have completed it.

First job, remove the seats, center console, carpet and side trim pieces.

Then I determined where I needed to cut the firewall by tapping on it and listening for the hollow parts. It may be necessary to cut a small hole in the center big enough to feel around in there and then cut some more.

As you can see, on the driver's side, you HAVE TO BE CAREFUL! The gasoline inlet tube runs from the filler spout, down through the firewall behind the driver's seat. DO NOT CUT INTO IT! (just had to warn for safety reasons)

The passenger side is a little easier, but the space you can cut out is also a little smaller. I used a dremel tool with cut-off wheels to cut through the thin sheet metal.

After the holes are cut, I began masking off the driver's side in order to mold the recessed part of the box.

Here you can see the fiberglass already laid into the recess in the firewall. I put two layers of glass in there just to make sure it is getting sealed and to add more strength.

[This message has been edited by 87GTBro (edited 07-15-2002).]

This is what the recessed part looked like after I pulled it from the firewall to let it cure.

That is all I have done so far. As I struggle with this project and a full time job, I will bring you updates as often as I can. Hope this helps somebody!

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[This message has been edited by 87GTBro (edited 07-15-2002).]

None of those pics work for me. But hope you get them up, I get a pair of JBL GT's in a couple of weeks and guess where they are going...

Now I just need an amp.

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^{The Black Beauty (85 GT) - Bustedato (86 SE, Parts car)
Don't sweat the petty things, and don't pet the sweaty things
AOL IM: KSSouter
MSN IM: I_R_Sootah@hotmail.com}

fixed

Looks like your doing an awesome job so far

how much leg room do you calculate you will loose?

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Steven Rossi
2M4 to GT conversion underway

Part of my goals for starting this project is to have full articulation of the seats.

I am 6'2" and I need all the leg room I can get. I will be making measurements and finding a sub to suit the space.

Another thing I might add is that this setup, when complete, might seem a little ricey to some of you guys. The front of the box is going to be part plexi-glass and I will have neon lights inside the sub box. It should add a nice touch.

87GTBro

It looks like your doing a great job with your project and documentation. Mine was done years ago (pre-InterNet and at the time, I never thought to document every step with photos. Watch for magnet size/basket depth on those subs you buy. Keep us posted.

My car's stereo site for newcomers http://www.geocities.com/fierosound/

Here's one of many pics of mine. I use a 10" sub that only needed .6cf of space. That way you don't have to make the "Box" so big. I only used 1/2 the space & can put my amps above the sub. I only took up about 3" of leg room. The subs still handle 300W RMS & 600W peak. Email me or PM for pics if you want. You will like it when your done, your doing a great job.... Keep us posted! Chris.

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88 Formula
WTB White 88 Formula t-tops w/5spd, pw,pl,cc,a/c,tan int.

i got some pointers. glassing the recess in is a good idea. i got my subs last fall to try this but haven't taken the time to work on it yet.

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Phil T.

start where you are,
use what you have,
do what you can.

oh you valley boys...............
Looks GREAT !!!
Maybe cut ALL THE way through the fire wall on the passenger side, Then you can change the spark plugs easier ! LOL
Just playing with ya!!!!

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ttt

Now that's a great Idea!!! LOL! I used a material called Peel-N-Seal. It's used for repairs on roofs. You just cut the size you want & peel off the backing & use a 1" wood or rubber roller, then roll over it to stick it to the metal. It's about 1/8" thick. It also helps in road noise. I sealed it with silicone. Works great. https://www.fiero.nl/forum/Forum1/HTML/019876.html

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88 Formula
WTB White 88 Formula t-tops w/5spd, pw,pl,cc,a/c,tan int.

I glassed in the recess on the passenger side tonight.

[This message has been edited by 87GTBro (edited 07-15-2002).]

87GT, howcome your pass side 'box' looks smalller than everyone elses cut-out??? Did you just not extend the sides as far as they can be cut??

Its not as big as Wheels1 did his. I was scared to cut that much off of the firewall... I didn't want to do anything irreversible. But the pic is decieving.. It is actually almost bigger than the driver's side in reality...

I was going for CF (cubic feet) space. I cut mine from the spot welds on the left side to about 2" from the right side. I needed .6cf of space. 87GT is going for magnet size. You can cut it as big as mine or just the size for the sub magnet to fit. Either way it will work fine. 87GT is doing a great job, I might try the fiberglass way next time. I'm going to do it to my 88 formula next week. It will be ready for the FOCA met in M.O. the 1th of aug. I'll take lots of pics also... Keep up the great job..... Chris.

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88 Formula
WTB White 88 Formula t-tops w/5spd, pw,pl,cc,a/c,tan int.

87gtbro, any more updates.
I have a few questions, Where do you run the speaker wire from the sub?, just drill a small hole in the wood framing?
Also how is the box frame attached to the firewall?, with screws or is it siliconed?
Where do i get the fiberboard? stereoshops or can i get it at local hardware stores.
I'm sure i'll have more q's as i go along.
Thanks Mike

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My Crappy Webpage http://www.geocities.com/billfredmike25/index.html

Wow! took awhile for the pictures to come up but pretty nice job.

Jade

The Fiberboard can be purchased fairly cheap at a large hardware store like Home Depot...
You want MDF also called Medium Density Fiberboard. This provides the best material, without increasing sub box resonance and tends to be forgiving when working with it.

Usually 3/4" is what you want to go with, although for less powerful subs I have seen 1/2". I tend to use 3/4" for anything under 1200 watts per speaker, and use the thicker (And heavier) 1" for large 15s and super high powered systems. Attachments to the rear firewall are made with heavy duty angle brackets attached to the box frame, and then mounted firmly to the firewall. Yes, you want a good heavy coat of silicone on the backside when you assemble. The box MUST be airtight...

Just answering some questions. Have done this in a BMW Z3 and did a similar install.

Wow... I'm impressed.

Seriously... I am...

Sorry I have not updated the thread. There are a few questions I need to answer. I am not making my boxes out of wood, but all fiberglass. I chose fiberglass because I can form it to the space behind the seats. This will allow me to maximize the c.f. of air space.

I have already done most of the backing for the driver's side. I will post pics when I get off work. (YES! I am here while at work. SHH!!! Don't tell my boss!)

Another thing I want to mention is that I am going to try to make these boxes removable.

Sweet, can't wait to see how you're gonna make it all out of fiberglass, i'll be waiting to see how it's done. I just started to cut out the firewall now, passenger side only for now.
Thanks Mike

I left those pieces in on my passenger side for support. It is nice strong steel so I figured it was there for a reason. IF it is possible to fit the sub in with those brackets there, I would. The magnet for my sub fit perfectly right between them.

I'd just like to butt in here for a moment to say that clear silicone is not the best thing to use for sealant. The fumes from the silicone will eat away at the glue holding the surround to the cone. I use Liquid Nails for my enclosures as it is not silicone based and still holds really well.

Wheels1 - it looks like you cut that whole bracket out of there, did you, have you had any structure problems with your car?

Okay guys, here is an update on the job. I am starting to feel overwhelmed with all the work I have ahead of me. I have a full poly bushing set, a rear sway bar, Intrax lowering springs, KYB shocks and struts, and my Stage 2 kit arrived today!!! USPS wouldn't leave it without a sig, so I have to pick it up at the Post Office tomorrow!!! I am SOOO excited!!!

OK, now for the update:

I installed the side trim piece and the center console back in the car so I can get an exact figure of the space I have available. I then covered the entire area with masking tape. I used 1.5" or even 2" masking tape.

Then I used the fiberglass matting and resin to form the shell, making sure I glassed in the recess I previously made. The rolls of paper you see were used to hold the fiberglass away from the vent for the computer and the other vent on the door side (I have no idea what that vent is for).

This is what it looked like after I pulled it from the car. I still need to plug up some holes that didn't quite get sealed right. Then I will build up the sides to add strength and enable me to start the front. Not a quick job I might add!

That's all for now! Anyone want to volunteer to install all this stuff on my car?

[This message has been edited by 87GTBro (edited 07-19-2002).]

I'd love to help...but all i can do is watch...and remember my trip through installing subs in my 2M4

I want to buy a fiero and put 8 subs in it. That would be a prject and a half

2 front *ported*
2 trunk *ported
2 besind seats
1 center console
1 footwell

Here is my plan that i've been thinking through.

I'd begin with the Center Console
I would put a Pioneer 10" in there. Because the Pioneer have the sound of a 12" they don't *pop* as much, i like that because it would distract you less while driving. The Pioneers have a low hertz response and i find that PERFACT for the center console.

For behind the seats i'd go 12". I would want lower sounds to back up my Pioneer. I'd get 2 12" cerwin vegas. They have the best low range and almost no POP. It would be great for low bass parts. Great for in car stuff. But i'd get the lower powered ones. Maybe 400 watts Peak!. I'd make a rosewood box for them because rosewood (i fee) has a great 'resenation' and carrys that sound great. Plexy glass or Fiberglass would be great for the *pop* woofers.

For the footwell i would get the highest powerd 8" around. I'd go for a MTX. To support my ported subs. Anything will do

And all my porteds would be MTX. MTX is know to have the best *pop* sound from their 10" models...every one of them. So i'd get the MTX for the 10" under the hood and in the trunk.

This is all a dream...if anyone has a few grand to spare...i'll help!

[This message has been edited by stevenrossi (edited 07-19-2002).]

quote Originally posted by stevenrossi: I want to buy a fiero and put 8 subs in it. That would be a prject and a half 2 front *ported* 2 trunk *ported 2 besind seats 1 center console 1 footwell

I expect you're not in your 20s yet?Here's a Fiero with 2-10s and 2-12s, and yes, I've heard it personally. http://www.angelfire.com/ab4/fierostereo/

Don't forget that you'll need some Mids and Tweets for musical balance, otherwise your system will sound like nothing but cannon fire or thunder. You will also need some MAJOR amplification to drive all this stuff. And think about WHERE all this stuff will have to fit.

You may have to do what's been done here http://www.perigee.net/~lunapark/
Front trunk - all subs, rear trunk - all amplifiers.

Check out the installs here. You will see many cases of "the stereo that ate the car".
http://www.sounddomain.com/member_pages

My car's stereo here http://www.geocities.com/fierosound/

[This message has been edited by fierosound (edited 07-28-2002).]

I did cut the lower brace, I made 2 cuts in it & then pounded it down flat. I need the extra space for my magnets. I also used foam for all holes..here are some more pics of mine. Sorry for the late reply. Been busy working on my 88 Formula....If you need pics or any questions please email me. c1irsik1@swbell.net Thanks, Chris.

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88 Formula
WTB White 88 Formula t-tops w/5spd, pw,pl,cc,a/c,tan int.

[This message has been edited by Wheels1 (edited 10-26-2002).]

Oooh, the "pounding bass" versus the "acoustic perfection" argument.. acoustic perfection!

I just spent the better part of an hour cutting my hand(and my firewall) to hell. Got me a big old hole, now I just need to know how to mold fiberglass.

And yeah, this project needs to be completed by Monday, 7am, so I can drive it to work.. Muwahaha!

How much does sound deadening material cost?

I used a material called Peel-N-Seal. It's made for repairing roofs. It cost about $.08 squ. foot. It comes in many sizes. I got a roll 36" wide & 33.5ft. Cost about $80. & I have enough to do the doors & apply 2 layers to the floor. It has a adhesive backing so you can use a 2" roller to apply it to the metal. Works Great!..

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88 Formula
WTB White 88 Formula t-tops w/5spd, pw,pl,cc,a/c,tan int.

[This message has been edited by Wheels1 (edited 10-26-2002).]

I love that saftey fan!

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3800SC Poly, Koni, Enkei

Me Too!!! My dads shop...It was one of these "Look at what I found at the dump today" "It works great, but the shroud is bent, so just keep your fingers out of it".......Things...

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88 Formula
WTB White 88 Formula t-tops w/5spd, pw,pl,cc,a/c,tan int.

~Bump~

how's the install coming? We get an update Please.. Very interested in doing this to one of my fiero's

Sorry guys, I took a break to install the new suspension on the car. I have not done any additional work on the sub enclosures.

But now I have new KYB shocks and struts, Intrax lowering springs, Poly bushings all around and rear sway bar...

Well then, you get picks on the suspension install?

Not step-by-step, but I did take a few while installing them. I will show some later...
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Edit:

As promised, these are some shots I took while installing the suspension...

Passenger side, front

Driver's side, front

Rear wheel well gap...

Side shot of vehicle. This car has not been driven on the new poly bushings yet. I am expecting the front end to relax a little after driving it around. It looks close to normal stance in this pic.

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[This message has been edited by 87GTBro (edited 07-30-2002).]