How To Fit An Amp In A V36 Coupe

[The Max]

So, here I am with this V36 I've lusted after for so long but knowing full well I was going to have a hell of a project on my hands upgrading the audio to suit my taste. Thinking it was going to be Bose equipped because it was an SP package, I figured it would be relatively easy from a wiring point of view, at least.

Boy was I wrong. Getting an SP doesn't mean you get a Bose as part of the package ... that's still optional and in another thread which I won't bother with now as it has already been discussed enough.

Anyway, in the process of taking out the interior of the boot to figure out how to get to the rear speakers as part of the upgrade, I found the corner where I would typically expect to find the Bose rig if I had one. Thankfully, Nissan were thoughtful enough to still weld in a bunch of M6 studs in the boot floor and this gave me an ingenious idea for mounting my gear. Granted, I'm sure someone else has thought of and done the same so I'm not going to claim the holy grail in this but I am setting out to let everyone else know how it's done if they want to do the same. I also have Autocad drawings in a PDF, mainly for myself if I need to ever make another but also for anyone else who would like to make their own base plate.

So, here's what I prototyped using 1.6mm galvanised steel sheet. The bends aren't the greatest since I don't have a proper sheetmetal bender like we did in my high school. Man that thing was great to work with back in the day! Essentially, the base plate uses four of the M6 boot floor studs, accessible via the 16mm holes drilled in the top side of the plate so a 10mm socket can get in. Once it's mounted, then the amp or other device of your choice can be mounted on top of it, if you have more than one device.

I've gone for a stack, because I'm using a JBL MS-8 DSP and a Rockford Fosgate Power 850.4. Naturally, the amp will be sitting on top because it's generating the most heat. I wouldn't recommend using a stack in this corner for mounting two beefy amps together as there's not a lot of space for decent ventilation if going beyond one amp. Above the JBL DSP will be a second plate which mounts on the three 1/4" studs you see on the left and right as well as the pop rivetted strip sitting in the top right corner. I would have preferred to go with bending a strip out of the same plate itself but sadly I was working with sheets of 300 x 600mm. I should have bought myself a nice big chunk of 1200 x 2400 and deal with the excess. Anyway...

I'm using virtually every millimetre available in this corner underneath the OEM plastic shrouds that form the sides around the spare tyre. This is to allow for additional points where I might like to drill a hole or two for mounting cable management to keep everything neat and absolutely safe from harm. You probably can't see that I've bevelled the edges of the metal as well as the corners but that's an extra measure to then affixing the grommet strip around the edges. I take no chances with my installs - they're built to last.

Here you'll see the plate from the bottom with its four mounting feet ... extensions of strips from the side of the plate bent over in a U-shape sideways. I was in the process of gluing the foam sheet as an additional measure to protect the boot floor from direct metal contact. I know the HICAS, GPS and telephone adapter don't have anything under their steel but I don't give a rat's bum what Nissan do there. This is me.

Also, you'll see the 7 bolts that I have MIG welded to the plate. Yes, the last time I MIG welded was back in high school and I'm a little out of practice. After a few practice runs on some scrap, this is what I came up with and it's solid.

There are three 1/4" x 12mm bolts for mounting the upper plate for the amp on top. The four 3/16" x 15mm in the middle are for the JBL MS-8 DSP.

This is the top view. Note the 16mm access holes which are large enough for most 10mm sockets to fit for screwing down the nuts. Here you will see the fourth support strip which I've pop rivetted in to support the upper right corner of the upper amp plate. This will be affixed to the amp plate with a nut and bolt arrangement for relatively easy removal in service situations.

Here you can see the plate mounted in its final position. There's actually one more M6 stud in the boot floor located approximately in the middle of the plate but I elected not to use it. With the thick aluminium base of the JBL DSP, that will make the whole base plate even more rigid.

Getting the washers and nuts on isn't all that easy if you don't have Japanese mechanic's fingers but it is possible and not an exercise in patience and time-consuming hell. Anyway, the plate has been mounted using machine washers and nyloc nuts. This plate isn't going ANYWHERE.

In this photo, you can see the left mounting in a little more detail, with the washers and nyloc nuts. After test mounting the shroud over it earlier, there's only a few mm of gap in there so it's a perfect fit!

And here we are now with the JBL DSP mounted. Unfortunately, JBL put one bolt hole so close to their friggin' power terminal block that it's now impossible for me to rotate any nut of any profile on it!!! Seriously JBL, we're not all happy to use self-tappers and not all of us are necessarily working from the top down! Anyway, I'm going to start looking around for something cylindrical with perhaps a screwdriver slot in the top. This will at least be able to rotate and just fix that corner down. That said though, the other three are fastened using machine washers, spring washers and dome nuts. The dome nuts are preferable in the event we have a wire finding its way loose, which might otherwise abrade on any exposed thread.

Unfortunately, I screwed up the camera angle so it looks like it's actually mounted past the edge of the plate but I assure you it sits flush. Pushing it further to the left wasn't really possible given the location of the bolt in the top left corner. Any further and I would have had a very weak point in the plate for that bolt to carry any load.

The plastic shroud fits over this and only just. No rubbing, no noise, no modification to the shroud necessary. That said, there's a piece on the side which I'm tempted to Swiss cheese because while it's a structural piece to support whatever is in the boot's cargo area, I want the vehicle's vent to allow some kind of airflow in there too.

So that's where we are at so far. More build pics to come as I get more time off work. It's not easy engineering the move of a broadcast operation from one suburb to another.

Next step will be to do the same for the opposite side of the boot, where I need to mount my four crossovers for the Boston Acoustic speakers. The SPZ series, which are already installed in the front doors, have ridiculously huge crossovers compared to the old ProSeries that I'm still planning to use in the rear. Still, same principles will apply although now we're contending with the telephone adapter taking up some space too.

[t5iv]

Looks great mate! What speakers are you upgrading to?

[The Max]

There's more to come of course. Once I get the interior all out and do the wiring, I'll be able to finish the stack and you'll get to see the DSP + Amp stacked up.

Boston Acoustic SPZ60 in the front have already been installed though I need to re-wire since finding out that the woofers and tweeters are wired in parallel without even a friggin' capacitor inline! I've been keeping the volume low all this time just to avoid blowing the tweeters.

The rears get my old Maxima's speakers which are Boston Acoustic ProSeries 6.5x.

When it comes to car speakers, I've yet to find a pair that sound as accurate as these and still take a shitload of power. I'm happy with 100WRMS per speaker (front and rear) and these guys really take the (clean) power without issue. It's a shame Sony never made a 4 channel amp that was 100WRMS per channel. They only went as far as 75WRMS with my XM-754HX amp back in '99 and while it was a squeaky clean amp, it just didn't have the extra juice I was after.

[The Max]

I finally have an update now that I've had a bit of time off work and decent weather to work out in.

So, the stack itself has been completed though nothing actually connected as yet. I'm going to need a lot more time (and physical space) to start pulling out the interior in order to pass the power cabling and replace the rear speakers, among the alarm, remote starter and some other gizmos I need to add in.

What we have in terms of cabling hanging around on the JBL:

1) Subwoofer out lead (single)

2) Remote In (will check schematics to see if I can possibly get that feed from the Telephone Adapter in the boot rather than having to fish it out of the headunit).

3) Remote Out (to feed the amps)

4) Power (the figure 8 8GA cable)

Then there's the Rockford Fosgate amp:

1) Power (the 4GA cabling)

2) Not in place yet but the 8-core speaker cable to feed the crossovers (front and rear pairs) whenever that arrives from the supplier

One thing you'll notice soon in all this is that I like to use multicore cable wherever possible in the name of neatness and additional protection from the outer sheath. In every other instance, it's mesh and PVC loose-tube.

First up, preparations:

8GA lugs - I insist on using small eye lugs rather than forks. Why? If the screw on the terminal block should ever come loose, the terminal won't go flying out and potentially short against something. For further insurance, I always tie the cable to something on the framework that will prevent it from flying off anyway.

And now we have the amp stack plate mounted after having connected everything to the JBL DSP. Note the use of dome nuts, which can be seen from one of the mounts in the lower right corner. Again, this is to avoid any possible cabling getting loose and rubbing against otherwise potentially sharp edges on ordinary nuts and exposed screw threads. Here, we have the cabling for the RCA's (using 4-core individually shielded audio cable - Canford HSJ4 for those who are interested) to feed from the JBL's channels 1-4. This one has been passed through a grommet to avoid any unwanted abrasion from the sheet metal. Then we have the 4GA power cabling as well as the remote wire from the JBL's remote out. This has been passed through a gland as opposed to a grommet for not only avoid abrasion but to also clamp the cabling in place. To further remove any stresses on the power cable, I softened the insulation with minimal heat to make it a little more malleable and then cooled it at the right angle. The key here is zero stress and full protection of our cabling.

The 4GA power cable then tucks under the bottom plate, running along the boot floor and up towards the backseat where I have yet to plan the power distribution block mounting.

After which, we have the amp installed. It is held down using 50mm long M5 bolts and using spring washers to keep the nuts firmly in place despite road vibrations.

As stated, I haven't yet received my 8-core speaker cable so there's only 2 out of 3 parts taken care of here. You can see a little more detail with the RCAs and power cables. The two small holes you see drilled out to the right of the gland is for passing through a cable tie to hold the 8-core speaker cable when that arrives. This cable will be coming from the left of the amp and will pass along the top plate before going across the back of the boot to meet the crossovers on the other side. I figured there was just not enough room left for another gland or grommet to pass it underneath with the other cables.

A side view of the stack shows how closely packed together the two devices are. We've only got about 5mm spacing between them due to the little space afforded in this corner. Still, as the DSP isn't going to be doing anything more than just handling line-level signals (albeit the higher powered signals driving its input since we have no line level audio from the headunit), heat is expected to only be an issue with the amp. Hence, the gapping needed to be greater above the amp rather than the DSP. Here you can also see the single RCA lead for the subwoofer amp box hovering in the background. The idea will be to have the 8GA power, remote and audio cabling entering a Harting industrial connector which will have a Han A two-pole power connector and Han D multi-pin connector for the remote and audio signals. The connector would have been a bit smaller in the end but because my original plans were going to involve just a simple board sitting on the completed boot floor (as opposed to going internally like we are here), I had the 16-pin Han D ordered in for carrying a bunch of signals. Anyway, it's here now so may as well use it rather than let it go to waste.

A closer look at the gland taking in the power cable for the amp:

And a view of the stack from the front. Once cable paths are determined, expect these to be sheathed in some PVC loose-tube (as in flexible stuff).

So that's the update so far. When a little more time permits, I hope to have pulled out the interior for the various gizmos as well as the 2GA power cabling that needs to be fed back there and then the speakers back out to the front too.

Edited December 16, 2012 by The Max

[The Max]

Finally a bit more time and a lot more space (thanks to a good friend who kindly allowed me to use his home garage). The tasks were mighty difficult and I really didn't even consider taking any photos (let alone breakfast and lunch). I'll try to update in later stages with photos. The only thing I managed to do today was to replace the rear speakers with the Boston Acoustics and the wiring involving the following:

1. 2GA power cable (passenger side)
   

This was a bastard but only for the feeding through the grommet. Many posts I've seen on other forums suggested simply poking a hole into the rubber cap of the grommet behind the battery and then sealing it up with silicone. The perfectionist in me thought otherwise. I eventually managed to get the grommet cap off and pulled off the self-amalgamating tape one fragment at a time. The 2GA cable was a hell of a tight fit but I managed to get it through with no damage to my front guard thanks to the soft and fluffy blanket I covered it with out of sheer paranoia. Once I managed to roll the rubber cap back onto the grommet, I realised something. I broke one of the clips and that meant it wasn't clipping in. DAMN!! I'm going to order another one in from my favourite dealership and see how I can replace this without pulling out the loom. I'm thinking cutting a fine slit down the side so that I can slide it around the cabling and then tie it back together with a thin sheet of aluminium and a couple screws (pointing upward, of course). This is definitely not one of my proudest moments like I envisaged it to be. At any rate, I haven't yet sealed the engine bay side of the loom with self-amalgamating tape as I'm thinking I might have three more cables that need to be passed through that grommet if I can't find another grommet in the firewall.

Otherwise, passing the cable itself into the cabin was a piece of cake. The channelling on the passenger side of the vehicle was sufficiently generous to accept it as well as three other cables I'll mention later.

2. Jaycar 4-core speaker cable (passenger side)

This one was to take the front output of the head unit and feed it to the JBL DSP. Very easy to pass but not yet wired up as I've only taken out the kick panels and glovebox today.

3. Remote wire (passenger side)

I'm hoping the Clarion unit in these SPs actually does apply a remote out signal from pin 1 of their main connector. If not, I'll have to take the covers off the unit and see if I can trace a signal somewhere on the PCB that does act as a remote. The good thing about the JBL is that it can work with signals as low as 4V (from memory) so even a 5V logic signal would be sufficient. That saves me having to make a buffered switch to supply to the JBL.

4. JBL MS-8 display wire (passenger side)

As the JBL is remote controlled, there's an LCD display to connect as well. Mounting location at this point is not yet decided but I'm thinking either in the console cup holder (since I have a no liquids rule in the car) or otherwise mount it just ahead of the auto shifter. I'm more inclined to go with the cup holder. I may need to take out the bottom half of the back seat if I decide to slip it down the middle straight to the console rather than from the side.

5. Klotz 8-core speaker cable (driver's side)

The mutt's nuts. A bit too thick though to pass with the outer sheath on the driver's side past the halfway mark along the door sill. Passenger side has already been taken up by the 2GA and 4-core speaker cable there. Only option left was to strip the sheath off to allow it to be sheathed up to the middle point along the door sill and the rest in convoluted/split tubing. This is because inside the cable are 4 nylon ropes which keep the 8-core cable in an even circular arrangement. I would have preferred it to be a tighter loom but I can't find any 8-core that isn't for professional/PA use and given they drive 100VAC, that's why they're spaced out that way. Still, better this way than with 4 pairs of ordinary OFC cable or even 2 x 4-core cables because I have a proper colour code that I can use across all 4 speakers at the front (they're splits and the crossovers had to go in the boot due to their ridiculous size).

6. Rear parcel shelf speakers

This is definitely not for the faint of heart. To be able to merely slide out the rear shelf, you need to:

1. Remove the upper boot interior finishers
   
2. Unplug the brake light
   
3. Get inside the car and remove the front kick panels along with their side panels along the door sill
   
4. Remove the bottom and top halves of the backseat (in that sequence)
   
5. Remove the striker plastic cover for the backrest holding the seat in position when upright
   
6. Unclip the lower side covers
   
7. Now it gets difficult as you need to remove the upper side covers which involves:
   

• Unbolting the seatbelts up top
  
• Removing the side garnish which reveals the airbag curtains - this is the bastard part. There's a series of clips along the bottom to hold the garnish along with the side cover. There's also a clip closest to the B-pillar. However, there are two clips which are there to hold the panel in place so that when the curtains pop out, the panels stay where they are rather than smack you in the head. They don't just unclip. You need to somehow get a pair of pliers in there to twist them 90 degrees so they can then just slip out of their keyed hole. Pain in the bum.
  
• Then you can remove the rest of the upper side cover which then frees up the parcel tray cover to just slide off.
  

I hated this process with a passion. You definitely need a good set of trim removal tools (I use Bojo - they don't scratch and they don't break anything). Once it was done, speakers were mounted on a set of Scoshe ABS plastic 6x9 adapters slightly shaped with a Dremel to accommodate the slightly larger basket of the Boston ProSeries 6.5 as well as the accompanying tweeter along the side. The tweeters were placed at the outermost points for better separation. The adapters were screwed back down with some roofing sponge to absorb vibrations (none audible in the cabin when I drove off tonight) and using the same bolts (8mm hex heads) as with the original 6x9's. You don't have a lot of clearance from the windscreen so be sure to have a nice low-profile 8mm hex socket and a small low-profile ratchet for the job.

The key here was NO DRILLING OR CUTTING. I didn't want to butcher the panels like a mechanic friend of mine did back in my teenage years with the Maxima. Finding rattles after that was a mongrel of a job and proof of what happens when it's not done properly.

So in short, if you're planning on changing the rear speakers in a V36 coupe, it's definitely not for the impatient! Set aside a few hours for it and be very patient or you will definitely break something in the process!

[Chris Rogers]

fun car to work on eh?

good description of how its done btw.

[The Max]

I keep reminding myself that I'm doing this for the music I love.

No doubt you've had your share of fun with these vehicles and for that, I'm glad it's you who does it as a profession and not me. I'll stick to my broadcast job.

I just wish the firewall grommet was a little friendlier to access and work with. By the way, while I've got your attention, is there a second grommet of some reasonable description on the driver's side of these vehicles? Preferably behind a wheel well would be nice as it would be covered (and hidden) all 'round like the Maxima was.

Edited February 2, 2013 by The Max

[SMOKEYV35]

Nice install - similar to the way I did it also. I chose a 5ch amp so that I only needed to do one amp install in the boot. I can agree with you on how long it takes - I've done two full weekends on amp and headunit - and still no speakers hooked up!

[The Max]

Except you probably didn't break the firewall grommet behind the battery like I did.

Good thing I've got Raj from Steve Jarvin Nissan to rely on for all my spare parts needs.

[SMOKEYV35]

Hah - nah previous owner had already run 8ga through the grommet - so I used it to pull through 4ga and then sealed up with hot glue.

Have a look at my cooling fan setup - it might be a good idea for you with two amps stacked.

Can't attach pics from iPhone tho......but they're in the 'what have you done today' thread

[The Max]

Looks like you read my mind. Once all else has been finalised in the back there, I'll be doing the same. Only difference being though, I'll have to have my fan closer to the back of the vehicle which will mean taking the plastic shroud to a fabricator in order to get a duct fitted so that it has the same curve on the outside to accommodate the wheel but will still have the fan pointing straight at the equipment.

The Alpine is a nice solution to your problem and very well executed. Kudos. The only reason why it wasn't my solution is because I want more power. I chose to keep my sub in a removable box rather than integrate it into the boot space to allow for the bigger volume required behind the sub as well as the additional power all 'round. Otherwise, your solution would have been the ultimate.

[Chris Rogers]

re grommet. not really. that is one of the key ones in the car.

[The Max]

Chris, that's a bummer. Sounds like I'll need to extend at least one cable then as the device needs to take residence on the driver's side. I'll do some exploring when I take the wheel well covers off to do revert my headlights back to their factory HIDs (and finally have the AFS working again!). I'll be sure not to work on replacing that engine loom grommet until I've got that all sussed out. I don't want to have to pull the replacement one out again if I can avoid it. Thanks for responding to my queries mate. It just makes my homework that little bit easier when someone else has done the same work and is happy to share the information.

[The Max]

Well, after almost 2 months of too much stuff to do and not enough garage, what does an anti-theist do on a Good Friday after finishing work early? Work on his car with whatever limited space out of desperation and boredom.

I fixed - no, replaced - the firewall grommet I was talking about before. Found the part number on the part itself, ordered two of them through my highly esteemed spare parts guru Raj at Steve Jarvin and formulated my plan to try and replace it without having to extract the loom from inside the cabin (which was why I bought two, in case that hairbrained scheme was plain stupid). The key to removing the grommet ring is to peel off the rubber cap around the edge to expose the grommet ring, after which you can get in a screwdriver to push back the two clips so that the ring can be safely removed.

After getting a good look at the workshop manual, I found it was only 3 plugs on that loom inside the cabin with two intermediate connectors in between. The intermediate connectors were just another point at which the harness could be disconnected, allowing for easy replacement of the grommet. However, what I figured was with the limited space behind the ECU and SMJ (Super Multiple Junction) connector, it was better to just pull the whole length of the loom with the ECU connectors and SMJ connector as well.

So, away we went. Unplugged the three ECU connectors which are lever-action locking types. Press the small tab facing towards the rear of the vehicle and the lever will be free to glide in the same direction. This pushes out the connector, freeing it up from its receptacle. Repeat for the second one behind it and then the third one behind that. Note the different colours on each one so that you can plug them back into their correct order. Of course, the cabling itself is also varied in length which will help you if you forgot the order. In my case, it was (front to rear) grey, brown, black.

Then the same thing for the SMJ connector. There are two next to the ECU. The second one (i.e. on the right) is the one you need to pop the grey lever. You may need a little flatblade screwdriver to help you gently pop the lever off the tabs. Once you have those three connectors free (because the grey ECU cable actually is part of another harness that's unrelated here), you can then start with the engine harness protector sitting between the air inlet and the firewall (just under the windscreen). It's a long rectangular object with two locking tabs. First, you'll need to move the battery clamp hook. After which, once that's out of the way, you can remove the air vent inlet shroud which is held down by two plastic hand-nuts. This will give you the necessary clearance to start moving the engine harness.

Now, insert a small flatblade screwdriver into each tab and pull each end towards the front of the vehicle. Once freed, you can pull it forward and away from the windscreen to give you the slack you'll need to pull the loom out of the interior.

Ggently start pulling out the harness into the engine bay, paying particular attention to the connectors inside the cabin so that they don't get snagged onto any of the fixtures. If you can, get a second person to assist with the gentle pulling of the loom while you guide the connectors up to the firewall cutout. The cutout isn't big enough to accommodate all 3 plugs at once so pull them out one by one. Start with the SMJ connector as it has the most slack and will give back some real estate for the larger ECU connectors to pass through, one by one.

Once out, you can then slide off the busted grommet ring. Here's how mine was broken from my initial stupidity.

So, slide on the new one taking the same care.

Feed the cables back through the firewall cutout in the reverse order and again, take the same care in guiding the loom and connectors back to their rightful home. AND NEXT TIME DON'T BREAK THE FRIGGIN' GROMMET RING!!

I haven't clipped it back in as yet because I still have a couple more cables to pass through including the power cable for the amp. A key bit of advice for this is to have four things handy:

• Electrical tape (black)
• Self-amalgamating tape
• Cable lubricant or sewing machine oil
• Isopropyl-1 alcohol, preferably of the aerosol variety

The electrical tape is self-explanatory.

The self-amalgamating tape, I'll talk through for the uninitiated. This tape actually fuses to itself to form a homogenous rubber seal which is what you already have at the tip of that rubber cap that sits over the firewall grommet ring. Simply put, in this situation, it's better to use this than silicone sealant.

The cable lubricant is vital for passing through the cables, especially the fat ones or anything with a connector. This is a tight rubber opening. Sure, you can stretch it a bit over time using a blunt instrument but even then, you still risk unwanted friction against the existing wiring loom and that means a dysfunctional engine. You're messing with something pretty serious here so don't take the quick and dirty approach. Show some love to your V36 and it'll show you some love in return. All you need is a very thin coating over the first inch of the connector or cable that you're passing through. It's best to go from rear to front when inserting the cable (sounds kinky, I know) because you don't risk the rubber tip getting drawn in on itself and folding up. That'll only add to the friction.

When the cable has passed through and you've got it to the length you're after, wipe down the harness at the exit/front point, get a rag underneath and squirt some isopropyl alcohol over it to clean off any remaining lubricant. This will be important for the self-amalgamating tape to form a good seal.

Once I've completed the passing of the cables into the cabin, I'll be sure to take a photo every step of the way to demonstrate what I've discussed here.

Edited March 29, 2013 by The Max

[Chris Rogers]

Well written. I tend to pop the grommet off the lock first the pop the lock out.

Most if those are a bitch anyway. Mazda are the worst .

[The Max]

Maybe I was picking the wrong terms but that's exactly what I learned after I broke the original one. Rubber cap first, locking ring second. Steep learning curve.

[The Max]

And so the learning curve just gets steeper. In the process of installing the alarm and pulling out the AV unit to get started on the additional wiring to un-parallel the speaker connections in the doors, I made a startling discovery ... there are no longer grommets in the side panels passing wires through to the doors. Instead, they're all now IP67 connectors mounted directly on the panels and no spare wires that can be used!!

So, I've hit a temporary roadblock with this project having asked the question in the Modifications section to see if there is a better option than sacrificing the little light at the bottom of the door for the tweeter wires.

It's a shame I can't edit this thread because now I would preface the whole thread with "If you want to upgrade your stereo to its fullest extent, be sure to get a factory-fitted Bose system which will have all the wiring to accommodate this!!"

[Chris Rogers]

Or buy the matching harness

[The Max]

Or buy the matching harness

Is the interior side of the harness even interchangeable though?

[Chris Rogers]

Interchangeable yes. Pins are not on the other side from what I seem in the fsm