heinzboehmer's 2002 Topaz 6MT Coupe

[bmwfnatic]

Well, bad news. Looks like a detail was overlooked in my conversations with Carphonics.

Turns out Alpine CD53 headunits can't receive the stage 2 upgrade, so no nicer amps for me. As far as I can tell, only euro Siemens CD53s can be upgraded? Not entirely sure...

I still want to do some semi-scientific A/B testing against the junkyard unit, so my unit is on its way back. Would be nice to know if the increase in sound quality came from the maintenance done to the HK amp or from the headunit.

This also means that driving the speakers directly has been put on the back burner. If I'm really itching for some extra weight savings in the future, I'll stuff a modern amp into the CD53 and do it that way.

I have a mint, last revision euro siemens CD53 if you want.
They should work fine in the US, I think?

[heinzboehmer]

Anyway, back to more interesting things.

(Forking this off from this post in Bryson's build journal, to avoid clutter over there: https://nam3forum.com/forums/forum/m...909#post305909)

Was having trouble getting the CSL duct to fit, so I figured I would take the opportunity and fix my bumper fitment. Most of the foam on top of the carrier has been missing for as long as I can remember, so first order of business was to replace that.

I was too lazy to go out looking for a suitable material and the printer was already loaded with TPU, so I figured why not. Quickly designed some foam replacement pieces and printed them out. My recreation incorporates both the radius of the stock pieces and the draft on the top surface to butt the seal up against the rest of the front end assemblies:


First test fit:



First attempt was very close, just needed a couple tweaks to get the fit where I wanted it.

While V2 was printing, I prepped the carrier. Started by removing the old adhesive, which was as fun as it usually is. With all that mess gone, I gave the surface a quick scuff and mixed up some epoxy.

Bonding went smoothly. I even had some adhesive left over to form a bit of a fillet on the pieces. Hoping that helps make it a permanent repair:



Final touch was to add some Krytox to the surfaces that the bumper will slide over, in an attempt to avoid ripping these pieces out in the future.

Of course, I forgot to take pictures of everything reassembled, but trust me, it looks way better!

[heinzboehmer]

Well, bad news. Looks like a detail was overlooked in my conversations with Carphonics.

Turns out Alpine CD53 headunits can't receive the stage 2 upgrade, so no nicer amps for me. As far as I can tell, only euro Siemens CD53s can be upgraded? Not entirely sure...

I still want to do some semi-scientific A/B testing against the junkyard unit, so my unit is on its way back. Would be nice to know if the increase in sound quality came from the maintenance done to the HK amp or from the headunit.

This also means that driving the speakers directly has been put on the back burner. If I'm really itching for some extra weight savings in the future, I'll stuff a modern amp into the CD53 and do it that way.

[Obioban]

Would love to upgrade from the shitty mk4

Ha. I vastly prefer MK4 to any of the variants of iDrive I've owned (including 6, which I had in my i3). Adding wireless carplay to it would make me never want to change it.

Just because it amuses me every time, the iDrive in my current M5 (e60) racing the MKIV in my old (and vastly better car overall) e39 M5:

[0-60motorsports]

I'm working on retrofitting iDrive 6 if you're not in a rush. Closing out a dev project and then I'll have more time for it. You'll have to be comfortable with a bit of wiring depending on the level of integration you want, but nothing too crazy

Would love to upgrade from the shitty mk4

[heinzboehmer]

I'm working on retrofitting iDrive 6 if you're not in a rush. Closing out a dev project and then I'll have more time for it. You'll have to be comfortable with a bit of wiring depending on the level of integration you want, but nothing too crazy

Oh cool! You should definitely post about that on here once you get it working, sounds like an interesting project.

Personally, I want to keep my M3 screen-free, so I think I'll stick with the CD53. If I ever need more, I'll gut the headunit and just use it as a control interface for a modern amp.

[YoitsTmac]

I'm working on retrofitting iDrive 6 if you're not in a rush. Closing out a dev project and then I'll have more time for it. You'll have to be comfortable with a bit of wiring depending on the level of integration you want, but nothing too crazy

[heinzboehmer]

I did do that, yes.

I didn't do a before/after, but I did weight the pile of all the stuff I took out (battery cable to the trunk, entire stereo harness, trunk module scaffolding that holds the modules, all the stock modules (amp, bluetooth, DVD drive, MKIV display, etc), all the speakers other than the door speakers (which are now directly powered by the heat unit)-- and it was 46 lbs.

Can confirm two speakers plugged directly to the head unit is a sound quality downgrade- but I just listen to podcasts 99.9% of the time, so.... don't care.

Oh! Didn't realize you were only running on two speakers. In my case, if the radio is on, it's playing music, so two speakers probably won't cut for me. But, even half of the weight you saved is significant...

I guess project added to the ever growing list. Or, really, two projects (ordered by priority):

1. Shift weight balance rearwards by losing weight from the front or shifting components backwards (the front bracing should help with this as I want to remake the firewall plug and cabin air filter housing in CF)
2. Remove HK amp and redo audio harness to drive speakers directly from headunit

The only other thing to consider is sound quality. I bet it'll be fine in my semi-track-car'd out car, but I would like to confirm before permanently ripping things out. Simple patch plug connected to the HK amp harness connector should be good enough for the initial evaluation. Maybe I'll start there once I get my CD53 back.

[Obioban]

Yep, mostly sound quality.

Although Baris does advertise 50 Wrms per channel, so might be possible to drive the speakers directly. The weight savings potential is there, but redoing the entire harness sounds like a lot of (boring) work. My car's weight distribution is also a bit skewed towards the front right now (it's at something like 51:49 with me in it), so not exactly keen on making it even worse by removing the HK amp in the trunk. Maybe at some point in the future I'll revisit the idea, but for now, I just want the sound coming out of the speakers to stop being static-y

IObioban you did something along those lines in your car, right? Do you remember what the total weight savings were? Did you also get before/after weight distribution measurements?

I did do that, yes.

I didn't do a before/after, but I did weight the pile of all the stuff I took out (battery cable to the trunk, entire stereo harness, trunk module scaffolding that holds the modules, all the stock modules (amp, bluetooth, DVD drive, MKIV display, etc), all the speakers other than the door speakers (which are now directly powered by the heat unit)-- and it was 46 lbs.

Can confirm two speakers plugged directly to the head unit is a sound quality downgrade- but I just listen to podcasts 99.9% of the time, so.... don't care.

[heinzboehmer]

What are the benefits of amp upgrades in the head unit?

Yep, mostly sound quality.

Although Baris does advertise 50 Wrms per channel, so might be possible to drive the speakers directly. The weight savings potential is there, but redoing the entire harness sounds like a lot of (boring) work. My car's weight distribution is also a bit skewed towards the front right now (it's at something like 51:49 with me in it), so not exactly keen on making it even worse by removing the HK amp in the trunk. Maybe at some point in the future I'll revisit the idea, but for now, I just want the sound coming out of the speakers to stop being static-y

IObioban you did something along those lines in your car, right? Do you remember what the total weight savings were? Did you also get before/after weight distribution measurements?

[Obioban]

What are the benefits of amp upgrades in the head unit?

Sound quality.

[D-O]

What are the benefits of amp upgrades in the head unit?

[heinzboehmer]

I am, generally, a sucker for passively cooled electronic components. If you can skip having a fan, you have my attention.

No moving parts or dust accumulation ftw.

+1. Love the reliability of having no moving parts.

[Obioban]

I am, generally, a sucker for passively cooled electronic components. If you can skip having a fan, you have my attention.

No moving parts or dust accumulation ftw.

[heinzboehmer]

Drove the car around today. Amusingly, the junkyard radio sounds significantly better than what I sent out to upgrade, regardless of the worse aesthetic condition and broken display driver. Both were manufactured in 2004, so I don't think it actually matters which one gets the upgrade.

It'll be nice to have a decent reference point to compare the upgraded unit against, though. Pretty much anything is gonna sound better than the buzzy/static-y unit that was in there before (as proven by the junkyard radio).

Edit: I just realized I changed two variable at once, duh. I guess the only thing I can say for sure is that the system sounds better as a whole. Can't really attribute to the junkyard radio, as the HK amp could have also been playing a role.