RexNuts Subaru Forums

There's nothing like sweating your heart out DIY'ing something, and then being able to stand back and go "damn that looks good! and i did it all myself!"

Mate, i couldn't agree with you more, which is why i love doing this stuff...

So now that the tune and performance side has been taken care of - for now anyway - i've finally started to get back into the stereo side. Way overdue i know.

Anyways, i was hoping to keep this thread in some sort of progressive order, showing the stereo in each stage as it was built, and as seen already, the last thing shown here was the A-pillars getting vacuum formed. Well, they've been refitted into the car, allowing me to remount the boost gauge, but for the moment, the tweeter holes remain empty.

I figured there was no point in continuing to finish the front speaker mounts first, because i wouldn't be able to power it all up without the boot done anyway, so i would have been left with no sound until the boot was completed, with amps etc installed.

So for the moment, i continued with the sound deadening of the front doors (which was actually done wayyyyyyy back when i did the rest of the sound deadening on the car! LOL! ), and last weekend installed a set of Crescendo Opus 1v2 splits into the front doors to tide me over for now. These are being run from my trusty Alpine CDA-9835 head unit, which delivers a solid 26wrms per speaker - not bad for an internal head unit amp hey?

Anyways, on with the pics!

Doors sound deadened generously with Dynamat Extreme, more will probably be added for the final speaker installation, along with the rest of the holes being sealed up. These were left open because i still need to access those areas to feed new speaker wiring through the door tubes etc.

Drivers side.


Passenger side.


18mm speaker spacers were made, painted and sealed with gasket tape as per usual.


Crescendo's revised T1RPv2 tweeter resides in the factory tweeter location in front of the door handle, and doesnt sound half bad with a little time alignment to be honest.


Crossovers were mounted on the inner door skin in a void in the door trim.


And then the door trim refitted - and it all looks factory again!


So with that out of the way, lets move onto the exciting part - the boot. As some may already be aware also, i've changed my proposed amp setup, moving away from the 5 Genesis Profile Ultra amps, and upgrading to a trio of TRU Technology Billet amps.

So instead of the following configuration:

Left CH:
1x Genesis Profile Two Ultra (Bridged to left Midbass)
1x Genesis Profile Four Ultra (Bridged to left Midrange and left Tweeter)
Right CH:
1x Genesis Profile Two Ultra (Bridged to right Midbass)
1x Genesis Profile Four Ultra (Bridged to right Midrange and right Tweeter)
Sub:
1x Genesis Profile Sub Ultra

I'll now have the following:

Left CH:
TRU Technology Billet B-4100S (Ch 1 to left tweeter, Ch 2 to left midrange, Ch3/4 bridged to left midbass)
Right CH:
TRU Technology Billet B-4100S (Ch 1 to left tweeter, Ch 2 to left midrange, Ch3/4 bridged to left midbass)
Sub:
TRU Technology Billet B-2200S (Ch1/2 Bridged to sub)

After a month or so wait for a brand new batch of Billets to arrive in the country (special ordered with sequential serial numbers), it then came time to start designing the boot install.

So without further ado, i give you - "Project WRX Boot v1.0"

Design Ideas:
- Retain spare wheel access
- Make hinged false floor to hold the amps
- Have the amps appear to be floating
- Have a 'bath' type setup, with the inside of the bath painted the same colour as the car.
- Utilise space between rear strut towers for the subwoofer enclosure.
- Angle the subbox to the back of the back seat.
- Have both the sub and processor on display on the front of the subbox.

So we can skip some of the build pics, but i made the enclosure out of 19mm marine ply wood in order to save weight also. The angle of the back seat was actually quite sharp, which meant that the subbox ended up bring pretty shallow, but very wide, achieving something like 50L from memory. The downside was that it also severely limited my subwoofer choices to all of about 2 options, due to lack of mounting depth.

You can see what i mean below.


The back was carefully shaped to fit in under the bracing under the parcel shelf too - A LOT of time went into getting the box to sit as far back into that void as possible!


The 'bath' sidewalls marked out onto the 12mm ply wood floor, and fitted once the sub box was put into place.




And the proposed amp layout is as follows. Once the amps are mounted, the floor will be able to be lifted to still access the spare tyre.

So on with the pics...















And thats pretty much as far as it got. I then tore it all out and have decided to start from scratch.

So what now?

Looks good.. How easy would it be to access the spare wheel? Wouldnt it be fairly heavy?

Yep, you're right Mikey. Not only that, the range of motion was severely limited due to the sub being on the front of the box there.

Hence why the last sentence says i've scrapped that idea/layout entirely and will be starting from scratch! Its going to be nothing like that now. lol

You want something crazy..

Under the boot lid!

Very challenging but i think would look great..

On to some stereo updates for once.

So here it is - "Project WRX Boot v2.0"

Design Ideas:
- Get the sub into the spare wheel well to give me more room and mounting options for the amps
- Figure out the rest later :silly:

So i started with my Dynamatted boot floor from ages ago.


Then added some 3mm Dynaliner in the 'main' contact areas, curves and high spots of the wheel well, to help decouple the fibreglass mould/shell from the car itself.


Taped up the boot generously with some 2" masking tape.


Then foiled the whole thing.


Cut up the fibreglass matting ready to lay - notice that its thicker matting than normal (600gsm i think, may be 750gsm, i can't remember now!)


First layer complete - the thicker matting REALLY drinks the resin!


Skipped some steps and pics here, but this is now layer 3, just before the mould was 'popped' and removed from the car.


With the mould out of the car, its a bit easier to add more layers. In between each layer, the dry fibreglass was scuffed up with sandpaper to help each layer stick to the previous one.


This is after layer 5. Scuffed up, ready for the last layer!


A 6th and final layer was added, then it was time to find out the internal volume of the wheel well. A cardboard 'back plate' was made and taped in.


Poured in some foam bean bag beans, and scooped them out 1 litre at a time. A tip for anyone wanting to try this, keep a hand written tally, because you WILL lose count if you try to count it in your head. It took me 3 goes to get it! haha...


Total internal volume is pretty much smack bang on 49 litres. Then i drew on some more outlines ready for the mould to be trimmed and cut.


Once trimmed, i measured some of the offcuts to see the overall thickness of the mould. A solid 10mm thick, sturdy enough to stand on without flexing and will easily take the punishment almost any sub can throw at it! That other offcut in the background measured 13mm thick in one area, so that should be more than enough!


Thats all for now. More pics to come this week.

Cheers for looking.

Rick.

More Pics slick Rick

Ask, and ye shall receive, my friend!

Anyways, on with a little more progress...

The boot mould was then trimmed and any excess fibreglass removed. This is it back in the car to make sure it still fit nicely - and as expected, a very snug fit.


Now for the frame 'build up'. I experimented with some different thickness woods, and ended up with 19mm x 42mm strip to level off the mould to the boot. You can see that the diff hump behind the rear seat is actually higher than the rest of the boot. This worked perfectly and gives me a level floor once the sub box 'lid' is in place.


A piece of 19mm plywood makes up the back plate of the enclosure.


Holes countersunk into the fibreglass to ensure precise fitment into the wheel well.


The frame complete. Generous amounts of liquid nails seals the uneven gap between the fibreglass and the wood, and the frame pieces are secured with screws.


First layer of liquid sound deadening of Fhrx Studios fame. This stuff is unbelievably good.


Second layer on and set.


Third and final coat, then the frame was sanded with a board file to ensure its all level, and again refitted to the car. You can see i cut the top corner out of the frame to allow for cabling to pass under the floor - also the reason i chose to build the 'frame' on top of the fibreglass, rather than mould the fibreglass to it.


More 19mm plywood makes up the floor - and gives me a blank canvas to work with now - and HEAPS more room!


More soon...

Cheers for looking,
Rick.

How much weight would this complete sub enclosure add you recon ??

Hard to say, all depends on the thickness of the fibreglass. Its reasonably heavy, not has heavy as an MDF enclosure though.

I am kinda concerned with weight, so have been saving where i can, but this car is being built with stereo in mind first, performance second.

I still have a metal amp rack, about 18kg worth of amps and a second battery to go into the boot yet! Thats not including any cabling or the sub itself yet either!

Once its done, i'll get it weighted (won't be looking forward to that! haha!) and then look into more performance upgrades - bigger turbo and a retune is what i'm thinking!

And stiffer rear springs to hold it all off the ground

Coming along very nicely though!

The more updates i read the more impressed i am, well done Rick, i might give you a yell next time i'm down that way and finish work a bit early to come have a look.

Looking good Rick!

Why did you not link me to this before?!!

and it looks like you are using alot less Dynamat than your last car

haha, that too mate!


No problems mate, you're more than welcome anytime! Just give me a heads up.


Thanks Nath! Yep, a fair bit less than the last car i think.

Anyways, continuing this on...

I did some fiddling the other day in the boot with a couple of possible amp layout options.

Thoughts are welcome! Option 1?


Option 2?


Option 3?


Option 4?


Option 5?


Then thought i'd share my collection of Stinger HPM goodies that i've had slowly growing for the past 12 months or so! Special thanks to the boys at Stinger Australia for helping me with everything needed to wire up the WRX! wave.gif


Then i got a bit excited, so i took a pic of the interior...


And an hour later, it looked like this...

Speaking of collecting equipment, I've decided to retire my trusty Boston G5-12, and Santa was good to me in 2011, delivering one of these for me:



I spent quite a bit of time demo'ing one after reading nothing but good things about it and instantly fell in love. That was only off modest power too, and my TT amp will be feeding it even more. That bass that it produces is phenominal - i recommend that if anyone has a chance to demo one, do so!

Anywho, there has been some progress made once i decided how i want to have the 3 amps look.

Basically the idea is to have them pretty much floating, and laid back toward the back seat on an angle. Then when the back seats are folded down, you can look in through the back seat and see the amps internals (since they have perspex backing plates), which will also be reflected off the mirrors on the floor.

Its a little hard to explain and the pics at this stage won't do it justice, but it'll all make sense once its together and finished.

First of all, its made from metal. Mild steel. Yes it adds weight to do the car. I'll live with it, and if it slows the car down too much, i'll do more performance mods later to compensate. So no need to remind me about how much weight its going to add - i already know. That said, surprisingly, the frame i have thus far isn't too heavy, so as long as its strong, and holds everything in place how i want, i'm happy.

So, it begins with two pieces of 6mm x 50mm flat bar that will be the 'feet' as such that get secured to the car itself. These will be secured through the body and into the chassis. A quick inspection under the car revealed two spare M12 nuts welded into the chassis, so some holes were drilled into the body in order to utilise them. A piece of 25mm x 25mm RHS tube runs left to right across the width of the car, and two 4mm x 40mm flat bar pieces extend from that to provide a further two mounting points to the top of the diff hump.


Test fitted in to the car, you can see that the added height of the RHS tube allows the middle supports to sit level and extend to the top of the diff hump which is raised from the factory.


There were two holes in the diff hump from the factory, so we welded in some nuts to allow us to use these as mounting points. Two M8 bolts hold the amp rack to this point.


From there, we had to space up the next two supports in order to 'level off' the rack and clear the service holes for the fuel pump. Some more RHS tube and 4mm flat bar was used.


Leveled off perfectly - now we have a flat area to play with!


Out of the car so you can see it properly.


So with the 'base' frame tacked up and solidly mounted with a combination of M8 and M12 bolts, now it was time to add the 'auxiliary' frame work that is destined to actually hold the amps. Some more 4mm flat bar was used between the framework, which also acts as reinforcement.


Close up of left and right. The 4mm flat bar pieces that run front to back are what the vertical amp supports are going to weld to. A little hard to understand now, but it'll all make sense soon.



The 20mm wide flat bar piece that runs along the back of the rack, closes off the rack nice and square, allowing me a point of reference to finish to, have the mirrors cut to, and also make a trim piece that will extend from there, to the back seat, to hide the hinges and mess when the seats fold down.


The completed 'base' frame out of the car.


Now i'm just waiting on the vertical uprights to be cut via water jet from some 15mm plate. As mentioned, these will then be welded to the frame pieces that run front to back, allowing the amps to be bolted to the front, and achieve the floating look i'm after.

Once thats all tacked up, i can then mount the rear amps, and start making the brackets to hold the last amp infront of it all. Then it'll be off to the welders to get TIG'd up nice and strong!

Hopefully it all makes sense? More pics soon.

Cheers,
Rick.

Heres a little more progress of the amp rack - vertical supports finally arrived.

Firstly, a HUGE HUGE thank you to Henry/'audioquest' on MEA for helping to put me onto the right people in order to get the following pieces made for my amp rack - I cannot thank him enough for his efforts with this, even going to the lengths of picking up the pieces and delivering them to Fhrx so it'd be easier for me to pick them up. Thanks Henry! You're an absolute legend! wave.gif

So without further ado, a couple of water jet cut, 15mm stainless steel vertical uprights, destined to be welded to the amp rack, and hold the amps up. I now just need to get them drilled and threads tapped into them.


And a couple of custom CNC machined, TRU Technology badges made - but more on those later!


Once its all welded together, i'll weigh it, with and without the amps, and then decide if i go ahead with it all or not. I am conscious about the weight to a degree, but we'll see what happens.

More pics soon, comments welcome!

Rick.

Insane. Just so awesomely insane!

Thanks mate, i appreciate the comments.

Still not 100% sure if i'll end up using the metal rack etc, but the option is there.

More updates to come very soon!

Anyways, here's some updates with the car. Yet again, there stereo has been put on the back burner to make way for some performance upgrades. What can I say, the performance bug has bitten hard too, so there's just no stopping it now.

This upgrade is probably one of the best i've done to the car so far, and a handful of people do already know about it.

So here goes - the 2005 STi 6 speed gearbox swap.

To cut a long story short, the decision to do this upgrade wasn't really planned or expected, things just kind of fell into place and i had to run with it because the opportunity was too good to pass up. The ad for the gearbox package went online on a Sunday afternoon, at which point, knowing the price for the whole package was a bargain, i sent a message to the seller to just inquire and find out more info. Monday morning rolls around and - coincidently! - i get a call from a fellow WRX owner saying he'd blown his 5 speed gearbox and asking if i knew of anyone with a 5 speed for sale. Then the light bulb went off in my head, if i could time this right, i could pull my working 5 speed gearbox from my car, sell it, and replace it with the STi 6 speed!

As most people know, the early GC8 5 speed gearboxes are notoriously well known for being made of "glass and paper mache", so it made sense to get some money back from my working gearbox before it inevitably broke and was worth essentially nothing - and having broken one 5 speed before, i knew it was the smartest thing to do, and a wise investment for the car.

Again, long story short, the 05 STi 6 speed package - which included; STi 6 speed gearbox and shifter assembly, DCCD auto/manual switch and scroll wheel, STi tail shaft, matching ratio STi R180 plated LSD rear diff, starter motor, 6sp clutch kit, 6sp flywheel, front and rear STi drive shafts - was purchased, 5 speed gearbox and diff was removed and sold.

This post documents the process, and also shows some of the aftermarket goodies i picked up for the conversion along the way.

Firstly, we have the gearbox itself after arriving. A dodgy pic, as it was from my phone! Its a 2005 STi gearbox featuring DCCD (Driver Controlled Centre Differential). 35:65 Front:Rear torque split, with helical front LSD.


Since it was a couple of weeks before it went into the car, i also collected a few goodies for the conversion:

• Exedy Heavy Duty clutch kit (the 6sp can take it, you wouldn't dare put one of these in front of a 5sp though!)
• DCCDPro DCCD controller (all the way from Canada, because the DCCD controller is a part of the ECU in the 2005 STi)
• Kartboy front and rear shifter linkage bushes (replaces the soft rubber OEM bushes for a firmer shift feel)
• Kartboy 6 speed gearknob
• Cobb Tuning double adjustable short shifter (this was bought primarily for the height adjustment. In GC8's the OEM shifters tend to sit very tall due to the shallower centre console)
• OEM Subaru front and rear diff seals (always worth replacing seals in times like these! Much easier when everything is out of the car)

So we'll start with the installation of the aftermarket bits and pieces first. Here's a close up of the new parts - all of which possess amazing feel, ingenuity and flawless build quality. Thanks again go out to Scott from Shift Auto Parts and Dan from Car Mods Australia for hooking me up with these bits and pieces!


This is what the OEM shifter assembly looks like.


And then the shifter assembly built with the aftermarket parts


And finally, in comparison to an OEM one. As mentioned, i went for the Cobb Tuning double adjustable short shifter, as it allows me to lower the height independently from the throw - which is a necessity in the GC8 since the centre console is shallower than it's 2005 GDB counterpart (meaning that the OEM shifter would sit very high!). I've left the throw adjustment in the factory position, as the STi throw is quite short and tight as it is.


Moving on to the DCCDPro installation. Since my car obviously doesn't have the OEM plugs necessary for the DCCD auto/manual switch and scroll wheel, the only logical choice was to solder some fly leads directly onto the pins and add my own plugs.


On the plus side, i conveniently had a couple of useless 'coin slots' in my centre console that perfectly accommodated the addition of the new switches for that 'from the factory' look.


And in they went - who'd have known they weren't meant to be there?


The controller itself uses a combination of a dual axis G-sensor and throttle position references to calculate the best ratio of torque split between front and back wheels (diffs) - all in real time. So i made a small alloy bracket for the G-sensor so it can be fixed firmly to a handbrake bolt under the centre console.


The DCCDPro controller was sourced from Jeff from DCCDPro in Canada, he's honestly such a great person to deal with and just have a general chat to about cars - i cannot recommend his service and product enough, especially after all the questions i asked over email! Here's the controller installed. Explanations below.


Then i also decided to fit up the stronger R180 STi plated LSD rear diff. When most do this 6sp conversion into a GC8, they compromise and use a matching ratio WRX R160 rear diff (weaker!), and that's because traditionally you need to do the rear STi hub conversion in order to fit the wider R180 diff and driveshafts/CVs. This means you then need to run the rear STi Brembo brakes, which is where it turns into a costly exercise!

I then got onto a bloke in the US, that produced some custom drive shaft 'races', that use the WRX/R160 driveshaft spline count, with the STi/R180 driveshaft ball bearing count, that allow you to make 'hybrid' drive shafts that are WRX on the hub side, and STi on the diff side. So i ordered those too and away we go!

And then these are the differences in the 'races' inside the CV joints. The left one is the WRX one (22 spline/6 ball) and right is STi (32 spline/8 ball). The middle is the 'hybrid' race (22 spline/8 ball). Slide the hybrid race onto your WRX driveshaft, and this allows you to then use the STi inner joint to fit the STi R180 diff! Meaning you keep the WRX hubs/brakes and don't need to swap anything else.


A pic of the WRX R160 diff (left) vs the STi R180 diff (right) - you can clearly see the size difference between the two.


Luckily, i also had a spare set of WRX driveshafts laying around, so i could build them outside the car all ready to do the in and out diff swap. Got some brand new CV boots, grease and clamps, so its all new under there!


Rear diff swapped in, and filled with Nulon oil (as was the gearbox).


Kartboy gearknob fitted.


Then i swapped it for the OEM STi one. Not sure why, but i prefer the slightly bigger and leather feel of the STi one over the Kartboy. But believe it or not, i alternate between the two on occasion. Keen eyes will also notice the change from the rubber gear boot to an MY00 WRX leather one, which was much easier to fit over the larger 6sp shifter.


And that's the 6 speed swap 95% complete! The last thing to do is a custom LED array that displays the DCCD output in real time. I'm working on that at the moment, and figuring out the best way to fit it into the dash. A bit of custom work is necessary to 'massage' that into the dash to make sure it looks factory.

More pics to come soon!

Cheers for reading,
Rick.