E89 3DM Motorsport E89 Z4 Atacama Yellow Build

[fmorelli]

Posted originally on 07-23-2017:

Quote:

Originally Posted by Lurcher Quote: Originally Posted by fmorelli But here's my curiosity. So does the Z4 have a 9-channel DSP/amp? That is, all speakers are powered from that amp? That's the lead question to the next - is the wiring setup on the bimmertech done so the output line to the center channel is dead? Obviously if there are 9 power wires out, this would only push 8? Good question. I'd just say that the center was a summed channel from FL & FR - but then it would be powered regardless. So not the right answer Then I would say the subs are possibly bridged together (so the center gets it's own discrete channel). I'd have to plug my laptop in to my amp to see if this is how it's arranged - but I'm almost betting this is the case. I highly doubt BMW would build anything like that for a low volume car. but... Just checked realoem, the 676 Hifi amp is just for us! The 677 Pro also fits the X5... I'm still betting the amps 8 channels and the subs got a single channel

 

[fmorelli]

Posted originally on 07-23-2017:

Quote:

Originally Posted by Lurcher I'd have to plug my laptop in to my amp to see if this is how it's arranged - but I'm almost betting this is the case.

If you get a chance, let me know. I'm not quite there yet in my installation.

I know it is nuts, but Z4 does seem to be unique. The 6.5" footwells as best as I can tell are completely unique to our cars. So while I have an F30 map supplied by bimmertech for my e89 z4 (and they say they've done other Z4's), I don't buy that it makes any sense to the least of which the speakers are not the same.

If you find we are in a bridged setup I'll eat my Turner Motorsports hat! But you may have called that right!

Filippo

 

[fmorelli]

Posted originally on 07-23-2017:

Quote:

Originally Posted by NoQuarter 8 channels: The center channel is it's own channel The left and right woofer is the same channel Linkye

Super helpful. Thanks much!

Filippo

 

[fmorelli]

Posted originally on 07-23-2017:

Quote:

Originally Posted by NoQuarter 8 channels: The center channel is it's own channel The left and right woofer is the same channel

And just to be specific, the footwell mid-bass woofers are bridged. I gotta say, correct me if I'm wrong but that's some hinky shit. First why on earth did BMW decide that the Z4, the smallest of all their cars, needed footwell mid-bass woofers, when none of their other cars needed it? Next, who bridges a left and right speaker together, at least that is not a subwoofer (since channel separation is a non-issue for very low frequency non-directional)?

It would be better to kill the center channel and use the channel to get the footwell woofers each on their own dedicated line. I digress.

Filippo

 

[fmorelli]

Posted originally on 07-23-2017:

Quote:

Originally Posted by Lurcher Crap, I had to go back and re-read that - and yea WTF BMW? I thought the subs would be "mono". not the 6.5.... OK - I'll get into the software in the morning and see how mine is set-up. 102 F outside and 91 in the garage right now....

THat would be helpful. So bimmertech's existing harness for the E89 Z4 is wrong. It killed the bridged mid-bass footwell woofers. They are fixing that and getting it out to the two (?) e89 Z4 owners of that amp. Insane. Where is the rest of the world, lol.

Okay I've been thinking about this and would like your thought. I'm thinking about making a harness to route the center channel wiring down to the bridged footwell woofer. The bridged woofer as I read the ETK is in the passenger right side. So anyway, I'd run the center channel down there. Then, I'd hook the right-side footwell woofer to the center channel wire instead of the bridge wire. Then obviously the center channel speaker is no longer connected. This would allow the car to have 8 channels, no bridging BS across channels. Mid-ranges bridges seems like a really bad idea. And for that matter, a center channel in a stereo seems like the answer to a question no one ever asked. Given the DSP setup, the car can be tuned appropriately for this setup.

Thoughts? Am I missing something or getting something wrong?

Filippo

 

[fmorelli]

Posted originally on 07-29-2017:

Quote:

Originally Posted by Lurcher My amp (for the record: Audioson AP8.9 bit - same as yours, different software) got installed "correctly", with the 6.5" channels separate and the woofers separate (no change) as well.

So you have the amp installed with stock speakers, but are about to upgrade all the speakers using Jenherts? Can you post what you are installing?

I don't think this is the same amp as mine. The Audiotech Fischer, which bimmertech uses, has the following specs:
8-channels
at 4 Ohms 8 x 55 Watts / 110 Watts
at 2 Ohms 8 x 70 Watts / 140 Watts
THD < 0,02 %
4 x Highlevel, 1 x Aux, 1 x Optical
DSP Processing Power: 172 MHz, DSP Resolution 56 Bit

Quote:

Originally Posted by Lurcher PM me with your email and I'll send you my sound file. The extension is different in the sound files of my 2 amps (A-Fischer PP82DSP in the x3), but I bet they will either work or you may have to change the extension. There is no way to print the config (sucks). Worse case I can take some pics and post here.

Done. What software are you using?

Quote:

Originally Posted by Lurcher Time to get sweaty and install the new speakers (Jenherts...)

Quote:

Originally Posted by Lurcher So, I'd be doing exactly what you are suggesting - use the center channel wiring, run and extension down to the right 6.5" and call it a day. In the software you can rename everything anyway.

I will try and work on that now (I just took a break from the garage to come in and read your note). I'll shoot photos if I figure out the harness/routing/connector.

Quote:

Originally Posted by Lurcher My next question is how are BimmerNav "rewiring" the new harness? Is the old one the right one now to use for this change?

So we didn't get into what's wired wrong. My guess is that it is an F30 type harness or something, that doesn't plumb the footwell woofers (since they don't have them). The cursing part of the E89 Z4 is that, while it uses parts bin stuff from the E9x, E46, or is forward used in the F30 ... there is plenty of stuff that is just ever-so-slightly different.

Quote:

Originally Posted by Lurcher And just to close out - center channel is good for all of the DVDs we play while driving....great marketing...

Really the question is ... why on earth, BMW, would you plumb a near useless center channel, and bridge a mid-range speaker which muddies stereo separation? Spend less money, kill the center channel, wire the footwells correctly, and be done. What a mystery ...

Thanks for your posting ... very helpful!

Filippo

 

[fmorelli]

Posted originally on 07-30-2017:

Buttoning up the front of my car, I wanted to "fix" the headlight leveling setup I had on the car. The setup on the Z4 is pretty hokey. Unlike the E9x which has a boss on the arm to mount the headlight leveling arm, the E89 uses a metal strap (which of course does not fit the M3 arms, and the boss on the M3 is on the driver side versus the passenger side leveling unit on the Z4).

My previous bracket had broken, in part because the bracket has slits which leave very little metal. As a result when trying to wrap the bracket around the bigger M3 arms, and using some other means to clamp it in place (wire ties, coolant clamps, etc) it is easy for the metal to flex and break.

My new setup uses a T304 stainless steel wire tie, which is thin enough to feed through all the bracket slits. This helps distribute the stress (hopefully this one won't break).

A couple things on the install.

1. I flattened the bracket somewhat, where it goes across the top of the control arm. Couple needle nose pliers help.
2. Toward the end of the bracket, on one side, is a big square indent (probably for the clasp. I pushed it through to the other side which helped in running the wire tie through. This is obvious once trying to put this together.
3. I went through two wire ties, having a hard time cinching it the first time. The second time, I used locking pliers to push the bracket tight against the control arm (top to bottom). I then used pliers to help pull on the stainless wire tie while I used a screwdriver pushing against the wire tie clasp, to help cinch everything tight. Unlike a plastic tie, I discovered that one wants to pull the stainless tie parallel (straight) from the clasp. If one pulls at an angle it is easy to bend the inside clasp mechanism, and the tie will not hold securely.
4. As insurance, I put a black plastic wire tie on either side of the arm (stretching it nice and snug) to make sure nothing moves around.

Filippo

Here's how I routed the wire tie. Note that the top is flattened, and the little tab at the top is now pushed out versus in, so the wire tie goes through easily.

Mounted. (yes the arm looks oddly bent - that's how these come from BMW)

Here's the part number, for those looking: 37146783206

 

[fmorelli]

Posted originally on 07-30-2017:

Quote:

Originally Posted by Lurcher Amp is all but the "same". Bimmertech changes something on the board to call it "special". All the plugs and harnesses are the same - I'm using their wiring harness on my A-F amp in the X3 (per Nelson - even though A-F manual says not to use factory harness for power. Hmmm....) All of the BMWs with the 676 amp/speaker package us the same plug (I'd bet even the HK system uses the same plug). Most people probably see the value in the center (having one in a a home theater makes a difference) and with the ability to play DVD's - it's pretty much needed for "surround sound" (again - marketing the Logic 7 system) I'm using the audioson software - each manufacturer puts their own spin on it - I should have pulled up the A-F software to see if it would connect to my Audioson - something for another day. http://www.jehnert.de/shop/doorboard...woofer-system/ Just the mids-tweets - bought them used without woofers for a steal ...

[TBODY] [/TBODY]

 

[fmorelli]

Posted originally on 07-30-2017:

Alright, so today I worked on fixing the ridiculous bridged mid-bass woofers in the footwell. This is a surprisingly bad violation of basic principles for stereo sound. Effectively passing the left side encoded sound to the right speaker muddles the stereo separation in the mid-range. The following photos should help for anyone looking to do this. Simply since I am programming my own DSP, I am routing the dedicated center channel to the right footwell mid-bass woofer so it is now on its own dedicated channel (as it should be).

I pulled the center channel, ran a steel snake down from the small slot on the right side of the center channel frame until the snake came out of the passenger side footwell. I had a spare connector (thanks to Bavsound) for the new harness.

Filippo

The undertray panel is already removed below (3 torx bits), and the footwell woofer panel is also removed. Here I show the dash side panel removed. A plastic removal tool will help - it's just 3 clips and pulls out. I pulled the door rubber molding as well. Note the snake has already been pushed through and I've taped the extension wire to it so the wire can be pulled back up to the center channel.

Here you can see the snake heading down to the passenger side. The snake is what one would buy at the hardware store to snake a clog in plumbing.

Here is the snake coming through passenger footwell. Photo is taken from the floor upwards.

I ran the wire up behind the glove box.

Ok ... about 3 inches above the speaker hole is a 1" body hole and then into the speaker hole. This photo is taken from the floor upward.

Here's the speaker connection at the center channel.

Bavsound has connectors. I had this spare harness which I clipped off the male connector and used to make the center channel harness extension.

 

[fmorelli]

Posted on 07-31-2017:

Quote:

Originally Posted by Bstears Also, I was wondering about disconnecting the center channel and reassigning it for the midbass woofer. My understanding is that the head unit on the 676 sound system is always processing music in surround sound. We can't turn it off. So how much of the left and right channel is being sent to the center speaker? Is it redundant sound? Or will is it filtering sound out of the left and right channels for the center channel? I'm wondering if you will be missing out on sound by removing it. I believe the bavsound stage one upgrade includes a center channel replacement speaker which could mean it's important enough to upgrade.

I had a sneaky suspicion the "other" Z4 bimmertech amp guy would surface

... @Lurcher ostensibly has the same amp, and also a unique set of speakers, so helpful to have him in the mix as well.

General reading I've done, any number of folks have had positive results getting rid of their center channels (for whatever reason). In our case we have the need to do that as sending mid-range left side stereo signals to the right side footwell woofer is guaranteed to muddle stereo separation. To me, reprovisioning the center channel to create a proper right mid-bass woofer channel is a no brainer.

On the head unit, how is it that you know this center channel wizardry? In looking at the TIS, it seems to say that 4 channels come out of the head unit to the DSP. Here's the TIS description.

Here is the wiring out to the speakers, which was linked here before but the image is dead in the prior post.



(link to 676 HIFI speaker output schematic)

Filippo

 

[fmorelli]

Posted originally on 07-31-2017:

Quote:

Originally Posted by Bstears Sorry, I shouldn't have said head unit. You guys are much more knowledgeable about this stuff. Is the center channel simply outputting a combination of the left and right front speakers? Or is it processing the signal and pulling out voice?

Once you have the new amp in play, whatever BMW does with the center channel becomes moot.

Maceij @ bimmertech agreed with me - that the center channel should be repurposed to solve the bridging issue on the Z4. Hopefully the above photos help. The only trick is that you need to aquire a connector. One way to do it is to clip it off your stock center channel speaker (one can always resolder that on). I'm just adverse to cutting the factory wiring harness itself.

BTW I don't know that I know that much more ... I'm pushing my way through this bit by bit, and thankfully others here are providing some information and help. A high tide raises all boats.

Filippo

 

[fmorelli]

Posted originally on 07-31-2017:

Slight diversion. I purchased an Asus Zenbook a few weeks back, upgraded it to a 512SSD, and started working on getting a garage laptop set up so I can tune the stereo system DSP, and also so I can do programming and diagnostics on these modern BMW's. I need to sort out the software installs, but the hardware arrived from China today from a reputable seller and just over $200 shipped. Hard to beat,and this will pretty well talk to every BMW in a 20+ year span I've got sitting around here. In case anyone is interested, here's the seller's listing on Aliexpress. There are a few coupons which can drop the price. This is about $100 less than on eBay I believe.

I wish I had this when I was recently trying to diagnose the top issues on the Z4 ...

Filippo

 

[fmorelli]

Posted originally on 08-01-2017:

Quote:

Originally Posted by Bstears Those are good questions. First of all I just know it is a basic violation to send the left side signal to a right-side speaker. Only A/B testing of two configurations would tell us how much of a difference it makes, and I honestly have no guess. Bavsound's suggestion is not a bad one (low frequencies are non-directional), but really kills that speaker pair's contribution ... not to mention it is a mid-bass woofer, not a subwoofer. And if one had a factory speaker in the footwell, I don't even know if its performance specs would lend to the Bavsound suggestion (though they would know).

Sorry I don't have any clear answers. With the car apart for speaker installation, this is not a lot of work - that is, to run the wire as I did.
Filippo

 

[fmorelli]

Posted originally on 08-01-2017:

Quote:

Originally Posted by Lurcher I'd say that most people would put the amp in and call it a day - that is - if a specific sound file is installed/available for the z4.

To my knowledge there isn't a specific Z4 file, at least from bimmertech ... they sent me an F30 file, which we know doesn't have 6.5" footwells and the woofers are under seat, et cetera. Hopefully when I'm done, I'll be able to post my file with my specific configuration. And I may have someone with significant DSP experience, locally, do the tune. That's TBD though, as I'm not there yet.

Quote:

Originally Posted by Lurcher Or be lazy like I was and have a shop do all of this for you...

I actually considered this, but given the alcantara interior in my car I was concerned about someone screwing up panels ... and I know how these cars are assembled so I was more comfortable doing the work myself. BTW for those doing their own speaker installs, the Bavsound E89 Z4 video for Stage 1 coupled with the Z4-forum post on the subs ... I think the DIY is doable. But yeah I quality sound shop would do a great job I'm sure.

Quote:

Originally Posted by Lurcher Putting this amp in with zero configuration drove me nuts, as I tried it . It actually sounds worse than stock (as expected). Obviously Bavsound does not have a file for our cars, and they have only sold 2 of these amps, so they are probably not too concerned about any of this. I'd dare say 75% of the people getting this amp will never tune it farther than the stock configuration, regardless.

Drove you nuts, eh? So just to be clear, Bavsound won't sell this for the Z4. They actually sent me to bimmertech directly. Who sold two of these (at least that I know) and are rectifying a cabling issue.

Quote:

Originally Posted by Lurcher Lots of rambling, but on the e38 board, we saw a lot of new blood coming in when the price point got below ~$10k, and the modding was much more active. Will be interesting to see what happens here....

It is ironic (about these E89 Z4's) that they are no longer in production and we are still discovering these nuances in the cars. I'm kind of amazed, actually ...

Filippo

 

[fmorelli]

Posted originally on 08-02-2017:

Quote:

Originally Posted by Bstears So I disassembled the the area around the rear subwoofers, following that the post, which was so helpful. I didn't completely remove the large carpeted panel that covers the rear subwoofers as it has extensions under the center console and it seemed like I would break something to pull it completely out. But by unboltong it and releasing the tabs, it has plenty of movement in it. I put some sound deadening on the metal panel behind the subwoofer area just for good measure. After switching the factory woofers out of the housings and putting the new bavsound ghost woofers into the housings with a new seal, I installed the housings back into the car. I turned the system on before putting all the panels back together and quickly realized two things: one is that the bavsound ghost woofers definitely sound better, but still distort pretty easily. Maybe the new amp will help with this. Right now I'm using the stock amp. The second observation is that the bavsound woofers move more air because I got the annoying whistling sound when they would it hard. At first I thought the seal around the speakers must be leaking, but when I removed the housing from the car, the whistling stopped. I then considered a leak from the housings to the car where there is a space used for air flow. A new seal there didn't stop it either. I went to the trunk area where it sounded the loudest and put my finger over an empty bolt hole and the whistling stopped. I closed it with some sound deadening. Today I will install the rest of the stage one speaker upgrade and put the car back together!

That's good to know! I'll make sure to run my setup with everything apart. I will tell you, I did the Bavsound speakers first and then concluded that the amp didn't sound so great ... and then ordered the amp. Kind of how I dug myself into this hole.

I've not seen the Bavsound Ghost speakers (nor know their specs). The Rainbow IL-S8F (which is what was recommended to me by a German shop that sold several woofers which fit) are not particularly heavy nor have particularly large magnets. They are 90 db/w, 35hz-5k hz, 150W max @ 4ohms. Curious to see how they work. I hope to get to the woofers this weekend, once I get back from NYC.

Filippo

 

[fmorelli]

Posted originally on 08-02-2017:

Quote:

Originally Posted by Bstears I took pictures but they are too large to upload. I'll see if I can figure it out tonight. In the end, I may look into having a custom subwoofer enclosure installed in the depression in the trunk in between the existing woofers. I'm not looking for car rattling bass, just want it to be able to hit without distortion if I turn it up, especially with the top down. I have burmester in the C AMG and HK in the GL. I think I'm going to have to be ok with just ok sound out of the z4.

What problem are you having that makes you think you need a cabinet in the back? Also have you changed the 6.5" in the footwells?

I can't speak to the results yet, but with high quality 6.5" pair and a corresponding high quality 8" pair in that little car, driven by an amplifier with good, clean power, I expect it to pass muster. Also just remember that every 3db/w improvement in the speakers efficiency is like doubling amplifier power. I expect both replacement woofer sets to be far more efficient ... coupled with more power from the amp, should have reasonable headroom to push without breaking up. Being both small and in a reasonably sealed environment (though not tuned to anything ... lol) it should be pretty tight.

Okay ... I"m being hopeful!

Filippo

 

[fmorelli]

Posted originally on 08-03-2017:

Quote:

Originally Posted by Bstears So I should have clarified, the reason the woofers don't sound great is due to their physical limitations. Because of the narrow platform, they hit their limits quickly. So as the volume goes up, the woofers can't extend anymore and start slapping instead of thumping. If they were traditional 8" woofers, the bass would probably overwhelm a car that small. And I'm not cranking it way up, just moderate levels. As far as the kick panel speakers, I've read many times on different forums that most of the bass comes from them, but I can't see or hear that. I've watched them while playing music and I don't see much movement, especially compared to the 8" woofers. There's only so much air a 6.5" speaker can move. I think the only way to get the tight, low end bass is with a full sized 8" or 10" powered subwoofer. But I would only do that if I could get a nice, custom enclosure that isn't noticeable and doesnt take up a lot of room.

Got it. On the 6.5's I don't believe they are used on other current BMW's. I believe they were in the E85 and feedback on those speakers would be relative to that configuration (which I've not researched, but doubt is the same as the E89).

I've not looked at this in detail, but remember our 6.5's are bridged from BMW. Looking at the wiring diagram they bridge in parallel. Someone can check me on this but given the same amplifier that is not in bridged mode, when the speakers are run in parallel one is basically going to share the same power with two speakers (the resistance drops). Given all channels on the amp are the same, this means half the power output to each speaker. Not going to do a lot for moving air, right? If one goes to a dedicated channel to speaker configuration, you'll get more power ... kinda twice the power. If the speakers are also 3 or 6 or 9 db/w more efficient, two to four times the power again, efficiency-wise.

The Hertz 165.1's I've installed are 97db/w efficient ... I'd be surprised if the factory units reached 90db/w ... so my new speakers are like doubling to tripling amp power. And then ... I changed my amp, which I suspect about doubles the clean channel output ... and I went dedicated channels to the 6.5s ... doubling output to each speaker. They are 100hz to 10k ... so they don't go down so deep. I guess I'm saying, I expect a much greater contribution from the new configuration.

I'm curious to see where all this lands. Just need to get back home and do some more installation work!

Filippo

 

[fmorelli]

Posted originally on 08-04-2017:

Quote:

Originally Posted by Bstears So have you tested the 6.5" woofers with your new configuration? I'm interested to hear if you notice a big difference. Also, I'm interested to see how you like your new 8" subs. I ordered a combox from bimmer tech and just got it in the mail today. I hope to get it installed tonight and wrap up the 2 other speakers so I can be done with the audio phase! I bought the combox because I want to be able to Bluetooth stream music and have it integrate into the iDrive. Did any of you have the combox from the factory? Do you like it?

Quote:

Originally Posted by Lurcher I can tell you only some of the bass comes from the 6.5, as I can mute all of the other channels and see what they really add. I don't remember if separating the channels when the amp was installed sounds different - too long ago. They won't move too much regardless (especially mine) due to the frequency and the limited range I have them running at. Filippo - I'm betting you have to crank these down (spl wise) - but I'll take an efficient speaker any day. Hurry up and finish this - will ya - I'm waiting on your feedback to buy them. Another vendor making speakers for BMWs (just to have all this info in one place) is ETONhttp://www.eton-gmbh.com/en/products...o/bmw-upgrade/ No US distributors, but guy on 3 series forum gets these from Europe via ebay seller/distributor: acr-bad-hersfeld_de

Sorry guys, work travel is cramping my style but I head back from NYC tonight. I'll make progress on the weekend, but vacation next week and another week (it looks like) in NYC after ... so it's going to be a few weeks out, not to mention that I am waiting on a cable from bimmertech. The Hertz stuff is great - I ended up on that 6.5" because jake169 got a custom Hertz-based installation done on his car (separate amp and separate DSP), so he laid the tracks for that purchase.

I don't have iDrive. Bluetooth integration is moronic from BMW, who claims to be a technology company. mid-level VWs do better than my Z4 without iDrive. For non-iDrive I tried lots of stuff and settled on the Tune2Air WMA1000. Also sold as "Bovee WMA1000" I believe. Don't try the 2000 or 3000 ... won't work (ask me how I know). The WMA1000 does drop connection some times, but mostly works. Mostly. Argh.

I have someone I'm dealing with in Germany to buy German HIFI stuff. If you need contact info, send me a PM so I can provide his web site (he carries lots of German brands that have BMW fitment) and his Facebook ID so you can message with him. As a USA guy, he gave me a priced shipped with no VAT - Paypal invoice ... worked great.

Filippo

 

[fmorelli]

Posted originally on 08-07-2017:

Quote:

Originally Posted by Lurcher Quote: Originally Posted by fmorelli Sorry guys, work travel is cramping my style but I head back from NYC tonight. Filippo Damn that work "stuff"... As a road warrior myself - completely understand. Spent last ~yr up at National Grid out in Hicksville NY. Trying to get all of this stuff done (and housework) before I have to hit the road again. This gives me time to play some as well - next week getting by buddy's portable A/C for the garage and will be playing with some speaker options. I'll take some pictures of the software settings so we can compare notes.

Quote:

Originally Posted by Bstears So an update to the sound: after spending a week in the z4 l, I can tell you the bavsound stage 1 speaker upgrade made the sound significantly better. It's much clearer, and again, with the factory amp still. I highly recommend them. The ghost woofers were a lot of work to install, and although better, probably not worth the expense or work. I do want to add an 8" or 10" woofer to that space between the back seasts and behind the center console. There is a square indentation of about a foot by a foot in the wall behind the seats and in front of the trunk that exists for those that have the pass through option. I don't have that option, but I think it would be an excellent space for a nice subwoofer. With that addition, the sound system would be very good. What do you all think about open air subwoofers, where they are just mounted to the frame without an enclosure. Is the trunk small enough to act like an enclosure? I know a lot of factory subwoofers on the rear deck are open without an enclosure. It would make installation very easy and take up minimal space. Probably wouldn't sound as good as enclosed, but maybe if the trunk wad lined with sound insulation? The volume would also change depending on if the roof was up or down. Thoughts?

Not my specialty so I can't help. I'm sure you could build a small sealed box for a woofer in the ski compartment. It would not take up much trunk space and reality is our trunks are not super useful ... especially toward the rear bulkhead as you can't reach in there easily. My bimmertech amp (Audiotec Fischer) has pre-amp outs which would allow for an easy amp/sub add without any mods to the factory wiring.

Filippo

 

[fmorelli]

Posted originally on 10-20-2017:

I have posted here for a while as I've been on travel. The car had been off the road in early summer as I worked the stereo, but then I just wasn't around since late July to drive it. Given the nice Fall weather in Virginia, I'm trying to get some driving time, so I've delayed finishing the stereo.

Giving I'm driving it, we've started back up on getting tuning done, with B-Q Tuning doing his thing. I had been seeing some strange CEL codes, but an adaptation reset seems to have taken care of that.

I just ordered bimmerlife coils which you can read about on other forums (e.g. spool street). These are R8/Lambo/BMW Motorsport "smart coils" that change how ignition is provided to the plugs and significantly increase the charge power. This allows running different plugs and a bigger gap. I plan to run NGK SILZBR8D8S plugs for the BMW N20. Two quicks notes: if you consider ordering a set, the Z4 needs a different harness so you want to give Alex a heads up so he gets your the right setup. Second, my understanding is that today these can only be run if you are tuning with MHD - there is a checkbox for this ignition in the options screen. I'm not sure what gets changed in the DME but I do know the smart coils sort out their own dwell (versus in the DME) and I don't require multi-spark (which I believe the BMW DME performs). Anyway we are out of my realm of knowledge on that, but Cobb does not support these coils today.

So my hope is to finish up tuning in the next six weeks or so, at least on pump gas (hint hint). Then when it gets cold the car will go on stands to get the rest of the stereo installed, and the KW V3s along with camber/caster plates.

With some luck, I have more planned for next year, but right now its time to finish the in-flight items. As usual there are a few Z4-owning suspects that have been super helpful in this journey. I won't name names as they know who they are.

Filippo