Karter16

PS5’s came to $1775.94. The fronts (245/40R18) were cheaper than the Potenza Sports, but the rears (255/40R18) were significantly more for whatever reason.

I ordered tires this evening. After much research I decided to go with the Bridgestone Potenza Sport. I had been planning to take the well-trod route of Michelin PS4S's, however they're not available in New Zealand (and importing tires was just going to be too expensive to make sense) in any of the sizes remotely close to what I need (I confirmed this with Michelin NZ directly), this was a surprise especially given I'd checked on their NZ website that those sizes were available here 👎 This meant I then needed to figure out alternative options. In Michelins that meant PSS's or PS5's (no Cup options available in NZ in the sizes I need). The PSS's are too old, and the PS5's while by all accounts very good had me a bit concerned about the softer tire wall than the PS4S. The RE050A's that I'm running currently, are fairly stiff in the sidewall department and while objectively terrible compared to modern options I am used to the stiffer sidewall. By moving to 18's I'm already introducing more compliance for a better ride and road stickability (that's the technical term 🙃), and I was a little concerned about also moving to an even softer sidewall as well. I then looked wider, and after a bunch of research, looking at what is available in NZ, settled on the Potenza Sport. The Potenza Race would be an even better option I think, but they're not available in 18in options. The RE71-RS's while the stickiness would have been giggle-worthy, don't give the same degree of feedback and would be impractical in wet conditions, so the Sport it is. TireReviews.com have a good review of it and on dry handling it's very close to the PS4S, slightly better in the wet, and ranks worse on comfort (due to the firmer sidewall), slightly worse on noise and worse on wear. The wear doesn't bother me as I won't do enough km's anyway, the firmer sidewall I'm okay with and the noise will still be a lot better than the RE050A's anyway. This is all splitting hairs of course, but might as well get the best option I can. Big shout out to @Palazzo for suggesting Costco. Bridgestone NZ direct have the best price out of the rest due to a special deal currently which comes to only $2376.32 NZD for all 4 tires fitted. Costco, for exactly the same thing, is $1379.94, plus in addition you get a $360 store credit as well. Given we regularly shop at Costco for essentials this means the end cost for the tires comes to $1020. Which is quite astonishing to me. That's significantly less than I paid for new performance tires for my 318i in 2007!

Couple of updates: 1: The wheels arrived today 🎉 Mandatory photo, although we all already know what ARC8's look like 🙃 2: The male MAF sensor connectors arrived. I don't actually have need of these for myself, but I finally came across them and thought I'd order some to confirm they're a match and if so share the details with everyone as saves having to pay Turner money for their relocation harnesses. These things appear to be the exact same item Turner are using and they come with the pins and seals. I ordered 5 of these for the princely sum of $9.58USD total including shipping. per-unit price is $1.24USD. You can purchase your own (you can order singles) here: https://www.hdconnectorstore.com/productdetail/32496.html

TunerPro have a bunch of xdf's (definition files for tunes) for the Motronics as well as binary reads of the tunes - might be worth poking in to: https://www.tunerpro.net/downloadBinDefs.htm#BMW

Yeah absolutely. I was going to reply to your thread when I got a chance. The key thing is to figure out what processor your ECU runs - I think you're Motronic 1.0 right which is some derivative of the Intel 8051 I believe. Ghidra has def files for the 8051 I believe so you might be in luck. The second thing which is really needed is some sort of definition file which describes the locations in memory of parameters, etc. so you've got something to start with. From there it's a case of loading in Ghidra, trying to find code blocks, data blocks, etc. In terms of other tools it's pretty much just been Excel, TextEdit, and the like. Do you have a read of the program ROM from your ECU?

Well it's been an exciting weekend. On Thursday I got stuck into the additional CAN message project. As a recap the idea here is to add an additional function into the 0401 program binary to send an additional CAN message. I've given the new message the ARBID of 0x7D0 which makes it lower priority than all other CAN messages. The format of the message is: There's basically 4 parts to achieving this: 1: Create a new function that replicates the existing function to send CAN messages from the DME. It needs to be recreated as we need space for the extra instructions to call an additional CAN message. 2: Modify the 10ms task to point to our new function instead of the original. 3: Load our new CAN message definition into the CAN config table in the program ROM. 4: Create a new function to assemble the new CAN message and push the frame to the CAN buffer. The fun part is that this needs to be done by modifying the machine code in the binary, no easy way to write assembly or C here! I got the above done on Thursday, spent code-checking it and then flashed it to my car on Saturday morning. As soon as I turned the ignition on I could tell something was wrong as the DSC light was flashing. All modules relying on outbound CAN were throwing errors. A review of what I'd done revealed a dumb mistake. I was trying to use slot 17 of a 15 slot buffer 🤦‍♂️. Anyway it was an easy fix and v1.1 ran without issue, and I connected to the MK60 with INPA and could view live CAN data, so I knew the standard CAN messages were working fine. I'm not actually set up for CAN logging so at this point I shipped the binary off to Bryson for further testing. I was very excited to get this back from him showing the new message being logged: Bryson then setup his logger with the appropriate conversion factors and has been able to log AQ_REL, Lambda Integrator, etc. at 100Hz instead of the 5Hz or so that you get over DS2. He's posted a link to the log which you can find in his post here I'm super stoked that this has worked out. In addition to being very useful for tuning, it also proves that these sorts of modifications are possible and that the disassembly work is good enough to understand what's going on to the degree that it's possible to make working changes and additions to the program. Also - the new wheels are in the country and should hopefully arrive end of next week. Tomorrow's job is sorting out tires.

Well I placed the order with Apex last night. I've taken some good advice and gone with 18x9 up front (245/40) and 18x9.5 (255/40) at the back, which gets closer to square, while also getting me a good offset (ET42) at the front. Why not go fully square? Firstly, I don't drive the car enough km's for it to really matter from a tyre wear perspective - these new tyres will likely go the way of the old ones before I wear them out. Secondly it means I don't have to worry about spacers on the rear wheels like I would really need to if I went square to suit the fronts. In NZ wheel spacers automatically mean you need a low volume vehicle cert which, as previously covered, I am intending to avoid. I used willtheyfit.com to compare this setup with the various stock M3/CSL setups, and got a little concerned about how close the edge of the tyre tread will end up to the front spring perch on the Koni's. As has been identified by others the shape of the perch on the front right strut lends itself to running slightly closer to the tyre, and it's very close indeed. Although the new setup is a few mm shorter it's also closer to the strut and I was concerned it might be too close. When I compared the measurements against my car I couldn't see how it was going to work. Then when running the comparison for the 3rd time I realised I had made the amateur mistake of relying on a (top-google-ranked) post on another forum where that person had misquoted the offset on the 19in Style 67's. With the correct offset keyed in I was then satisfied that the new wheels should be an appropriate fit. The wheels are coming UPS expedited, so will likely be the usual case of arriving in New Zealand in a week or so and then spending the next week sitting in the distribution centre in Takanini. I'll get some quotes for tires this week so that they're ready to go when the wheels get here. Thanks everyone for your thoughts and advice on this, suddenly urgent, project!

Thanks for this - great review!

Thanks heaps for this - obviously my searching last night sucked! Given I've put less than 25,000km on the car in the last 10 years I'd say the 40,000km life won't be a problem lol. Great idea! hadn't thought of that - thank you!

What I really want is the PSS5 but they're not released in anything under 20 inches yet 😛 General consensus from what I've read is that the PS4S is the one to have, so plan to stick with that.

Well I found a circumferential crack in the inside wall of the front right today... The tires are old and I've been keeping an eye on them for this exact reason. I was hoping to get another 6-12 months out of them, but that's not going to happen and I need to get this sorted. My plan was (and probably still is) to shelve the 19in Style 67's and get some 18in ARC-8's (original I know, but quite simply can't come up with a better weight/quality/value/looks combination) and buy the new rubber for those rather than the 19s. I'm focused on driving experience and the 18s will be much better suited to Auckland roads than the 19s plus the weight savings will be very welcome. I'm thinking to go with 8.5" fronts and 9.5" rears with ETs to match to keep close to CSL spec. Apex suggest 235/40 for the fronts and 265/35 for the rears, but Michelin PS4S's don't come in a 235/40R18, so I'm wondering whether 225/45 and 255/40 would be a suitable option as that's very close to OE specs as it pertains to circumference.

Time for a quick update on a few things. I've been doing a bunch of playing around with the VE tuning process for a couple of reasons: Firstly when I was working through documenting how the CSL MAP Sensor is used in the DME it occurred to me that it was probably a good idea to take the MAP Sensor out of the loop of the RF calculation while performing the VE tuning process, as otherwise it would be compensating for underlying inaccuracies in the VE table and otherwise masking and making things more difficult. Secondly when going through the disassembly in detail I uncovered that the AQ_REL value that is logged from DS2 (in TestO) is not in fact the value that is used for the CSL AlphaN table. Rather a modified form of AQ_REL is used which inflates the AQ_REL value by a varying amount below 2400 RPM. Addressing the first piece is a case of changing a parameter in the partial binary to disable the MAP sensor, and I solved the second piece with a spreadsheet to convert TestO logs before putting them through the rest of the VE tuning process. This has been a great success. In the space of 3 tuning runs I've gone from something that (even after earlier VE tuning without addressing these two things) felt like an AlphaN tune (which it absolutely is with the MAP sensor turned off), to something so good, it feels like the MAP sensor is enabled, even though it isn't. (of course this won't extend to changing atmospheric conditions, etc. but gives you an idea of the improvement). Particularly low RPM rev matching is superb now with the AQ_REL values that are logged being accurately used to adjust the VE table. After just 3 runs everything is consolidating beautifully around a lambda of 1.0. (the couple of cells that show greater change are cells that I didn't manage to hit in previous runs). I've also been doing some investigation into adding an additional CANBUS message for the DME to send to allow for high data rate acquisition of key variables that currently aren't on CAN. This is a project that requires modifying the program ROM and as such will be a decent chunk of work to get done, but there are a few people keen for this and it seems like a fun winter challenge to figure out. I do want to spend some time working through the safety concept mechanisms to ensure that the safeguards in place in the DME would appropriately handle any edge case bugs or timing/performance issues that might be inadvertently introduced by such a change, but both the Master and Slave CPUs independently handle all key safety functionality, so given the changes will be only to the Master program ROM the risk should be manageable. I'm also satisfied now that the CF-Nylon version of the MAP sensor adapter is up to the job. I'll try mailing (rather than couriering) one to bmwfnatic as a test to see if the postal service accept it (it's right on the 10mm thickness limit). If that all goes okay then it will be practical to make these available to others at a reasonable price (no one will want to pay the $$$ for courier shipping from New Zealand). I'm pretty staunchly of the view that I don't want to make money out of this hobby and its community. I'd much rather contribute in ways that we can all openly benefit and learn from. But also I have a bag of these things sitting on my desk that won't get used otherwise and it seems a few people are keen. I'm thinking that I'll work out a price that covers the portion of the printing cost + postage + a few bucks to cover my time to package and send (and share that cost breakdown with everyone for transparency) and that way people who would find it easier to pay to get one of these can. Important to note that the CAD file for this is freely available here so if you have a printer / have a mate who has a printer / want to order your own from somewhere else you should totally go do that instead 🙂

Finally made it to this thread! As soon as I saw your car I knew today was the day! here’s the matching photo I took:

Pretty sure I've finally found a source for the male MAF sensor connector that allows for MOQ of 1 (and it's cheap to boot). This is what I'm talking about: I've ordered a couple to check and confirm, but if it is then this is the missing piece for people to be able to build their own harness extensions (and IAT relocation extensions I guess, not that I think they're good idea) without having to pay Turner mark-up. It also means anyone wanting to do what I did (keep the MAF connector and wire up for MAP sensor) doesn't have to buy a Turner extension just to then hack it up to add on the Bosch MAP sensor connector, etc. I'll wait til these arrive and I've confirmed and then put up a post with all the various part numbers needed to do this.

Whole family (including myself) are sick this weekend so took the opportunity to try out doing a VE table tuning run with the MAP sensor turned off. I've been wanting to do this for a while as theoretically it's another variable that can be removed from the process. With the MAP sensor taken out of the RF calculation path the car is essentially running in "Alpha-N Mode". My theory behind this is that depending on point in time conditions the MAP sensor is adjusting the final RF either up or down from what's calculated from the VE table. While this is desirable in day to day use, for the VE tuning process it's an unwelcome additional variable. Unfortunately I can't really think of an objective way to measure the impact of it to the VE tuning process, so it's really just a subjective assessment I guess. The difference with the MAP sensor disabled is immediately noticeable in the part-throttle conditions the MAP sensor targets. The car is less responsive and throttle input is jerkier and less consistent. I found a couple of RO/RPM conditions which I hadn't previously been able to flush out. I intend to do another tuning run tomorrow or Monday on a day when I can get further out and up the RPM range more to get a more complete test. It would need more people to try this out and get their subjective feedback as well as to whether disabling the MAP sensor positively influences the VE tuning process (I think it will mostly be about the speed at which one arrives at the end result), but I am pleased to have finally proven out that changing the configuration byte from 0x12 to 0x02 does behave as expected. Oh and also gave the nylon MAP sensor adapter a couple of good heat cycles and then took it off and inspected it - appears to be unaffected by the heat so far, so off to a good start.

The MAP sensor adapter printed in CF-reinforced Nylon arrived today. Minimum order value applied so I'm now the proud owner of 12 of these. I'll try to install in the next couple of days. HDT is significantly higher than the CF-PETG I used previously.

Well yesterday and today I tackled a job I've long been putting off. Yesterday I took the headlining out of the car, and dropped it (along with the sunroof cover, etc) plus the BM-134 fabric off to a professional headliner upholsterer. The dude was a legend and had it ready for me to pick up this morning (think he was grateful that I'd done the hard work of taking it out of the car!). He was very complementary of the BM-134 fabric - he said it's a quality fabric with quality foam and was lovely to work with. I'll tackle pretty much any job on the car, but this is one of those few things I'm very happy to leave to a professional - the work is flawless and it looks incredible. For those wondering about the fabric match - I took some photos of the re-wrapped headliner against one of the interior trim pieces which has the original BMW fabric on it (non-foam-backed): It's a very close match and certainly once it's in the car you can't tell at all - the slight difference really only shows up in photos. Likewise it matches well against the new A/B/C pillar trim I bought (which fortunately all match each other as well - as that was a problem for a while): While the headliner was out I took the opportunity to pull out the wiring a PO had put in for a radar scanner - I removed the T-Tap connectors, insulated the wires and wrapped in Tessa tape: In order to remove the sunroof cover to retrim it I also had to remove the sunroof glass - I took the opportunity while it was out to give the frame a good clean and re-lubricate with graphite lubricant: I reinstalled the headliner and then got on to installing the new pillar trim - shiny new B-pillar covers: Then the C-pillars, along with the foam insulated clips: And lastly the A-pillar trims and inserts with the airbag logo on them. Notably the A pillar inserts are a significantly different shade to everything else. (which is hilarious given this is all new OE parts). If it annoys me too much I might order replacements and hope for a better match. I'm very happy to have this done - it's not a particularly fun job but very satisfying to have everything refreshed and like new. You can see the huge difference in shade between the new a-pillar and the insert 🙄.

Well 2 days of driving an excavator, 4 months of weekends, 300m of rebar, 14 tonnes of concrete, 232 CMU blocks, and a lot of manual labour my retaining wall is complete - finished backfilling it today. Starting to get a bit wet here for the winter so great timing. Bit of a general update on the car. The latest version of the SMG reservoir bracket is in use, I've got some more tweaks to make to it so will do that and print the latest iteration. The MAP sensor adapter in CF-PETG shows some evidence of softening. It seems, under the clamping force of the bolts, it's not quite up to the ~100 degree C temperature that the rail hits. Plan is to get this printed in GF-Nylon which should be able to handle beyond 150 degree C temps. I'm doing some preliminary work on the reinstallation of the trunk interior with the RACP brace in place. Working through a few things to get to a lightweight, high-quality solution that meets my need to make it look as OE as possible. The version of the CSL tune I've been running the last while seems super stable. Even as it's got colder here it's remained super smooth. Seems I've got the warm-up maps pretty much spot on. I still want to do some more fine-tuning, and in particular am keen to try out running the fuel tuning process with the MAP sensor integrator turned off, but it's not top of the priority list given what I'm currently running is so good. Planning to get the headliner out and off to the pros to redo with the BM-134 fabric that I have stashed. I've also got brand new A/B/C pillars to go in once it's reinstalled. Intend to make more progress with the 0401 disassembly as well - especially as the days get shorter and the weather gets worse. Lots of little bits and pieces on the go. I've also been enjoying driving the car. The refreshed diff bushes have eliminated any remaining clunk in the drivetrain. Combined with the smoothness of the CSL tune it makes for lots of enjoyable downshifts with no need for the manual throttle modulating that I'd previously gotten used to to minimize the thunk. Secondly the RACP brace has, in addition to providing top-side support to the RACP, made an enormous difference to the torsional rigidity of the rear of the car. It's a very significant improvement and I'm getting itchy to give the front of the car similar treatment 😛

pretty sure this breaks moderation rule #18...

Today I also finished up the repainting of the v brace and rear sway bar brackets project. I top coated them a week and a half ago and they've been resting while the enamel fully cured. Today I reinstalled them along with new hardware to match.

Another rainy day here so retaining wall is again on hold. I took the opportunity this morning to finally redo the matte screen overlay on the Xtrons head unit. I got the Xtrons about 16 months ago and have had a much better experience with it than I was expecting. I'm well decided that I'll be keeping it. one of the downsides of it, and many head units is the glossy screen. About a year ago I purchased a matte screen overlay to see if I liked it better. I did my best to line it up nicely but because I had to cut it to size the edges were visible and annoying to me. I've long intended to take the head unit out and disassemble it so that I could replace the overlay over the entire LCD screen so that the edges would be hidden by the bezel if that makes sense. Today was that day. Head unit out: Rear case off: Disconnect the two big ribbon cables between the chassis and the display and remove the 4x screws holding the display shield on. Then the display and shield pop out of the bezel: The screen with the old matte overlay on it: Old matte overlay removed: I didn't get any photos of applying the new overlay as both my wife and I were employed in getting it on and keeping the screen completely free of dust. We succeeded and the overlay went down perfectly: The new overlay with the protection layer removed: Then it was just a case of reinstalling back into the bezel: And reconnecting the ribbon cables and putting it all back together: I'm super happy with how this has turned out - we got the overlay to go down perfectly and it looks fantastic: While I had the unit out I took the opportunity to plug in the USB extension and install the latest firmware to address the issue with a greater than expected difference between volume levels 4 and 5. This was straightforward and did indeed fix the issue. Now that it's reinstalled I'll give the screen and the head unit a clean to get the fingerprints from install off. Good, quick rainy day project 🙂

Sill waiting for the ground to dry out a little bit before I progress the retaining wall so spent a couple of hours this afternoon taking the rear sway bar brackets and v brace off and cleaning them up. When Dad and I did the underbody refresh in 2017 we used an enamel black paint for most of the pieces, and 8 years on they still look amazing - wipe the road dust off and they look brand new still. There were a couple of pieces (the sway bar brackets and v brace) which we painted with exactly the same stuff, only silver instead of black. Unfortunately the silver kind of sucks in comparison to the black - presumably whatever they put in it to make it silver makes it more susceptible to surface rusting. So anyway - I took them off, stripped the enamel with acetone and then cleaned up the surfaces with some fine sandpaper before cleaning again with acetone and then undercoating. The pictures are a bit average because it's pretty late in the day here, but I'm sure you've all seen undercoated things before: Had something interesting happen when I was spraying the undercoat on. It went on beautifully and then I noticed along some of the edges that it looked like it was bubbling. *Cue confusion*. The surface was prepped well and was very clean so I wasn't sure what was going on - I've used this undercoat a bunch of times and it's always been lovely. Closer inspection revealed it was moisture beading on top of the paint. Actual paint surface is fine and the moisture evaporated again. I'm guessing that it must be close to dew point here right now and the propellant from the spray paint has cooled the surface of the metal just enough at the edges for moisture to condense. Anyway - the moisture evaporated after some minutes and the paint surface seems good. I'll double check it when it's set to make sure it has good adhesion.

I realised I never really updated on the bracket for the SMG reservoir. Since I installed the CSL airbox I've been running a prototype version of the bracket. Given it's a rainy Thursday here I thought since I'd proved the concept that I'd design up a more final version of the bracket. This is still a development version and you'll note there's a few things that need to be tidied up, but didn't want to go to too much effort until I've confirmed fitment of this latest version. I started by using my previous prototype to confirm the location of the bracket itself and mark where I wanted it with some blue masking tape. I then scanned the strut tower and loaded the (fairly untidy) mesh into Fusion to help with placing reference planes, etc. Because the tower is an irregular shape the bracket needs to account for this: Note that the final unit will have rubber stand offs on the back to help it sit well on the tower and not rub. The mounting point where it's attached to the stud on the strut tower also has a raised, angled boss as the stud is not perpendicular to the strut and this needs to be accounted for so that the nut clamps the mounting point properly. I'll get this version printed up and do another round of test fitting and any final adjustments before I tidy up the rough edges. Given my goal of not wanting to drill holes in my strut tower I think that this should be a pretty tidy end result.

Torrential rain yesterday and today so I can't do any work on my retaining wall at home. Got round to a little job I've been wanting to do for a while. The trim around the SMG shifter boot makes an annoying plastic on plastic creak sometimes when shifting, which isn't particularly pleasant from a driving experience point of view. Today I took the trim apart and used some tesa tape to insulate the clips and mating surfaces. I also gave everything a good clean while I had it apart. Put it back together and the squeaks are completely gone (unless I press very hard directly on the plastic trim), shifting is now a satisfying mechanical click, rather than the annoying creaking sound it could be before.

Had a great weekend working on the car. On Saturday morning Dad and I got the car up on stands and exhaust and driveshaft out. Unbolted the exhaust at the headers and dropped the whole thing, then the same with the driveshaft. So much faster than last time given we're just removing and reinstalling rather than taking it all apart to clean. I'm super happy with how everything under the car is holding up, it's 8 years since we did the underbody refresh and everything is looking really good under there. I did the new gear position sensor first, access is a bit of a mission but the mutilated allen key approach does work. The old sensor was extremely notchy and rough after 20 years of service. Worth noting that we ran the first part of the SMG adaption (up to the point it wants the car started) to make sure it was happy with the new GPS. After that we moved on to lowering the rear subframe to facilitate the installation of the Yurkan Cages 6 point brace. We took off the brake calipers and rear trailing arm pockets and lowered the entire thing about 100mm on a couple of jacks (to give us more control over forward/rearward weight distribution). That gave us enough access to unbolt the front RACP studs and get them out. We then jacked the subframe back into place and loosely bolted it, which gave us a better safety factor while working under it. At this point we drained the diff, swapped out the rear diff cover for a new one and reinstalled with new bolts and drain plugs. I've mentioned previously that I'd long experienced some clunkiness when shifting/loading/unloading the drivetrain. This was vastly improved by adapting the SMG. I wasn't sure whether what remained was the diff getting a bit tired or whether the rear bushes needed replacing but I was pleased on checking the diff that there is no detectable lash in the diff at all, likewise with the driveshaft. I was therefore pretty hopeful that it was just the rear diff bushes that were the culprit. The rest of the process was pretty straightforward, we unbolted one point at a time and using a threaded drill guide that dad turned on his lathe and an extra long 6mm drill bit we went up through each of the 4 points in turn. Then it was simply a case of come down from the top with a 10.5mm bit before running a tap on a long extension up from underneath to complete the thread the whole way through. With that done it was then a case of bolting in each of the 4 points and torquing to spec. The rest of the reassembly took a couple of hours and we had the car on the ground again. The install of the brace was super quick - fitment of the brace was absolutely perfect - Marin's fabrication is spot on. Then it was just a case of running the complete adaption on the SMG and going for a test drive. Today I drove the car on a route I'm very familiar with and I'm extremely pleased with the end result! The last of the clunkiness when shifting is now resolved. Even under heavy acceleration in S5/S6 all you get is the sound and surge of power. I'm super stoked. And the brace. Well, I know others have reported a big improvement, but I wasn't completely sure if I'd find the same. Suffice to say the improvement is not subtle! For me the rear has always felt slightly less co-ordinated than the front (not to say it's not objectively excellent to begin with, but it's always stood out to me that the car is just a little bit more put together in the front). Now with the brace it's the other way around! The change in stiffness is hugely noticeable even just driving around town. As soon as you get to a roundabout or uneven tarmac it becomes very apparent how much more rigidity there is. The car really feels glued together in the back now. I love it and am excited to go for a decent spirited drive.