Karter16's Silbergrau E46 M3 Journal

[karter16]

This weekend I made a start on preparation for installing the 6 point rear brace. The plan is to get as much pre-work done as possible so that the process of dropping the subframe and bolting through can be as straightforward as possible.

I got this done in a few hours here and there across Saturday and Sunday in between adventures with Mr 7, Mr 3 and Mrs Karter16.

First up is to remove the interior:



I need to get the isopropyl alcohol out and clean up the rear seat and prep it for repainting some rust spots, but I won't do that until the heavier prep-work is done.

Before I got started with drilling I wanted to place the brace in the car just to see, with my own eyes, the placement of the mounting points etc. I had all the measurements from Marin at Yurkan Cages, but figured seeing it with my own eyes would help avoid any mistakes.

I wanted to make sure though that I didn't damage the paint on the brace, so spent some time first taping up all of the contact surfaces:




I carefully dropped the brace into place (obviously sitting higher than it will eventually with the floor sheet metal in the way. But this meant I could sight the approximate locations and reassure myself about the approach.




Note: You don't see it in the photos because I removed some of it to get better lighting for photographs, but I was very careful to ensure that interior surfaces were covered and protected when drilling, cutting, sanding, etc. It's really worth taking the time to protect everything well.


First up to prepare for cutting the top layer of sheet metal is removing the two little brackets that sit atop the locations where the front mounts will go. The diameter of the hole for the spot weld is about 6mm, and I found a 7mm bit was necessary to drill out the weld entirely.






Note that the brackets are stuck on as well (presumable to hold them in place before being spot welded). I needed to carefully encourage them to lift off with a flathead screwdriver (which I taped with masking tape to protect the metal surfaces).




With these out of the way I then moved on to cutting the holes for the rear two mounts. I carefully measured and remeasured several times to make sure I was in exactly the right spot. I used a centre punch (always use a centre punch) to mark the point and then drilled out with a 3mm bit. I had some old, unused, BMW M TwinPower Turbo 10W60 which I used for lubricating on the drill bits and hole saw (only ever 10W60 for my car 😂).




Note: With things like this it's worth taking the time to clean your drill bits after each cut, that way they're clean for the next cut and aren't flinging more mess around than necessary.

I then drilled out to 6mm before making the final cut with the 44mm hole saw.




You can see in this photo that there was some overspill from when the BMW RACP "foam" resin procedure was done. I've only just realised I didn't take a photo, but the way I cleaned this up was to carefully down down as far as I dared with the hole saw (not wanting to damage the next layer of sheet metal) and then use a chisel to very careful chip away at the resin bit by bit. By carefully doing this I was able to completely clear it from the vicinity of the hole without causing any damage to anything else.

Side note: calling this stuff "foam" does a disservice to people's understanding of it. The stuff is much better described a plastic-like resin - It's absolutely solid stuff.

I then did the other side (the resin had only just domed up from underneath so didn't need to clean it up like on the left hand side. Pretty soon I had the rear points taken care of:






Then it was on to the front points, which are certainly the harder pair to do. I realised, as I went to write this, that I didn't take any photos of this in progress, probably because I was cramped in the back of the car and carefully concentrating on what I was doing. Essentially though it's a case of carefully measuring in from the sides and then siting the pilot hole in the right place. In order to do this correctly I used a flat edge on the top of the RACP and measured out and down to find the bottom edge of the pocket. I then split the distance in two horizontally and dropped down to get the centre point at which to drill the pilot hole. I then drilled this out to 6mm and "verticalized" it to guide the hole saw. I then cut down vertically from the top using the hole saw, and then cut out the bottom of the pocket with a cutting disk on the Dremel (highly recommend having/getting a Dremel if you're taking this job on).

Working carefully resulted in this (wife's beauty product as a conveniently sized stand in for 40mm tube steel):



After some careful work on both sides (including removing burrs with the sanding attachment on the Dremel) I then took the time to use a magnet to remove all trace of the cutting, including from inside the cavities. Handy tip - if you use a medical disposable rubber glove as a cover for your magnet it makes cleaning up easy. Each time the magnet is "full" just invert the finger of the glove and move on to the next finger, after 5 goes throw the glove away and grab the next one.




The front now looked like this:




I then dropped the brace back in to check the fit. Fitted into place first time! (obviously still sitting higher as it's resting on top of the rear shock mount nuts).






Having reached this point and confirming the fit I then took the brace back out and cleaned up the cuts and area around them (inside and out) with isopropyl alcohol, before applying a coat of kill rust undercoat to the exposed edges of the cuts. I have an enamel top coat in the same colour as the e-coat BMW used which I will apply as well, but only after confirming the fit once the new extended subframe bolts are in and I can check the fitment exactly. Until then the undercoat will protect the edges from rust.


I'm glad that I decided to tackle this part of the project separately, as it took a number of hours to do and means the top side is ready to go when we drop the subframe.


Oh, and in an entirely expected and predictable turn of events, the top side of the front right RACP mount has cracks in it. I'm unsurprised given the cracks that we welded on the bottom side when Dad and I did the reinforcement plates. We'll stop drill the cracks and weld prior to dropping the subframe. I wish it hadn't been quite so long between doing the plates and getting to the top side, but such have been the realities of dealing with medical kids. On the plus side the car has done very few km's since the plates were done!

[karter16]

My son and I spent some time this morning removing the rear bumper and having a look at why it sits so badly and with a view to affixing the replacement speed clip brackets to the kevlar support.



Unfortunately the reason is a little more serious than I was expecting. The rear bumper had been replaced prior to my ownership due to a collision (something I was aware of when I bought the car). I suspected that the reason that the bumper didn't sit well was because it wasn't installed properly. This was indeed the case, with the foam screws missing, etc. and the lower brackets of the rear bumper cut up, presumably to make the diffuser fit. I was expecting to have to get these items sorted and plastic weld the bumper, but I wasn't prepared for the fact that the kevlar support is damaged (in hindsight I should have realised it likely would be). The kevlar support has several folds/tears toward the centre of the piece which has broken the resin. This in turn appears to have allowed, over time, moisture to absorb into the kevlar weave. As a result the support appears to be beyond practical repair. Also as an integral part of the collision system I'm keen not to skimp on it.

The red outline in the photo below shows the affected section.




In the meantime we have reinstalled the bumper as-is, while I source a new kevlar support and a couple of other bits and pieces. Oh, and it's time to replace the exhaust hangers again...

Aren't old cars just the best!

[karter16]

Gave the car a quick wash this afternoon and was finally able to put the door trim back on the driver door. I took the trim off several months ago to adjust the drivers door window, but the rubber grommets on the clips were too hard and brittle to be able to use again, so had to wait for replacements from Schmiedmann (I ordered a significant amount for the future). Anyway, here the trim is with new clips ready to go back on.



And reinstalled.

[karter16]

Hell yeah, excited to see the results of the tuning. Don't forget the flap tables if you end up getting an aftermarket snorkel.

I just set all the flap opening tables to 100 rpm with Bryson's tune and it's been working great

Yeah I'm looking forward to having all the stuff here so that I can really get into it. Am doing what I can in advance in terms of getting my calculations in order etc. :-)

Good reminder thank you on the flap tables. I shall definitely make sure I don't forget them

[karter16]

Haimus snorkel is a good alternative. The only annoying thing is that the partition in the center opening for the upper and lower air feeds needs to be removed. They really should print it without that part.

Thanks yes I saw you mention this on someone else's thread - will definitely keep this in mind if I go the Haimus route!

[heinzboehmer]

Hell yeah, excited to see the results of the tuning. Don't forget the flap tables if you end up getting an aftermarket snorkel.

I just set all the flap opening tables to 100 rpm with Bryson's tune and it's been working great

[Slideways]

Haimus snorkel is a good alternative. The only annoying thing is that the partition in the center opening for the upper and lower air feeds needs to be removed. They really should print it without that part.

[karter16]

Got a chance this morning to quickly sort out and consolidate the various parts that have arrived over the last 6 weeks. I now have most of what I need to commence on the 6 point RSM/RACP brace install. I still have a few bits and pieces to get:

• Replacement diff fluid
• LH side tray to go with the non-CD changer trunk lining
• End caps for the 2x exposed tube ends on the brace
• Rubber seals/grommets for where the brace goes through the top layer of sheet metal to the rear RACP threaded sections

I'm looking forward to getting the new rear diff cover on and enjoying the new bushes. I'm curious to see if/what difference it makes.

Not pictured below is the brace and the LH side trunk lining.








I also now have in hand most of the OE items that I need for the airbox install. I'm still waiting on the CSL dipstick tube (that's currently slated to arrive sometime in November), and I have a few more bits and pieces to get for the wiring side of things, but most of the key bits are now in.



Edit: there's some bits missing in this photo but oh well...


I also ordered the airbox itself yesterday from Karbonius. With their standard 12 week lead time the theory is that it should arrive around Christmas or so, which will then mean I can play round with it over my (southern hemisphere) summer break. There'll be some downtime while I work through the install, get the wiring install just how I want it, iterate on the one piece SMG expansion tank bracket, etc. so summer break will be the perfect time for that.

I'll also be working on my own M3/CSL hybrid tune (basically doing a worse job of the amazing work that Bry5on is doing). This is probably the part I'm most excited about to be honest - as someone who studied as an embedded systems engineer (and now spends their days as an IT consultant) it's great fun getting into the weeds of the DME.

The one thing for the install that I haven't 100% committed on is the snorkel. I'm 85% sure I'll go with the Haimus resin snorkel, but keep holding off actually ordering it. I like the idea of the OE snorkel, but given my approach of keeping everything reversible/as unadulterated as possible, I'm not super keen on having to add the H-Bridge and associated componentry to the DME, plus the significant additional expense for something that I'm not confident would make that much difference to the end result.

I love the OE snorkel look (flat black contrasts well with the CF intake) and for this reason am not a fan of the Karbonius snorkel (if I went this route I'd want to paint it black and that's just silly). The Haimus snorkel seems to be the closest to the OE look, without the added complexity and cost of running a functioning flap. Maybe I'll convince myself that the flap is purely for noise control (even though I know it isn't really), and that therefore a simple snorkel with no flap is what BMW would have done in an alternate universe anyway.

Anyway - shaping up for some fun projects to work on in a few months!

[karter16]

Well I haven't had many updates the last couple of months - it's mostly been a case of hurry up and wait on parts deliveries, I've now received most of the parts I ordered back in June both for the rear shock mount brace install, as well as the OE parts needed for the CSL airbox install (just waiting on the factory to do a run of CSL dipstick tubes). A few weeks ago I also ordered a set of A/B/C pillar trims. I had been planning to go down the route of covering with BM-3109, but then discovered that the plastic mounting points on my current trims are damaged, and that I was therefore going to have to fork out for a new set. I ordered those a few weeks ago and looks as though they should arrive at the end of the year or so.

Last Friday I also dropped off the RSM brace to be powder coated, and yesterday it was ready to be picked up. I opted for matte black, as it matches the OE powder coat finish on items like the front strut bar, etc. My goal with this install is to make it look as OE as possible.

[karter16]

Another piece of the RSM/RACP brace puzzle arrived today.

As part of doing the brace the rear trim and carpet needs to be cut for the brace. I'd rather not cut up my original pieces so am sourcing spares. This one though I had to buy new as finding one in New Zealand was too much of a struggle. The left hand side trim that came with my car includes the larger space for the CD stacker, etc. Given I've removed the stacker and am just running the hi-fi amp I wanted to get the left hand trim to go with it so that I have more boot space (plus it will be an easier cut for the brace.

I was fortunate to find one on eBay at a very reasonable price with $39 international shipping (which was about $250 cheaper than shipping via Schmiedmann or the like) so I jumped on it, and it arrived today.

Also apologies to anyone who is upset by me planning to cut up a brand new item. It upsets me too 🙃

BNIB

[nyc951]

I took a small, and carefully controlled amount of flame to the buttons on the front seat belt latches today.

First up - please note that this process works to remove white oxidation and restore the red colour, but it will not work if the surface of the plastic has degraded too far. do not do this if you have any breakdown of the surface of the button.

To begin with I carefully cleaned the surface of the button. If you're going to heat up the surface of the plastic you do NOT want any dirt, skin oils, grime, etc. to be on the button. To ensure that I cleaned this well I used a small piece of magic eraser (note that magic eraser is abrasive and wouldn't normally be recommended on car surfaces, however in this case because we're effectively resurfacing the button the slight abrasion doesn't matter and helps make sure that all the dirt is removed). For the cleaning step I used the magic eraser with warm water with dish soap in it and gave the button a good scrub (be careful to not let water get down into the latch), making sure I worked carefully around the raised "PRESS" letters. I then rinsed off the remaining soap with several rounds of clean water, before carefully drying the button with paper towel. I then left it a few minutes to ensure all moisture on the surface of the button had evaporated.

Next step is to carefully use aluminium foil to shield the rest of the latch. I was very careful to make sure that the foil wasn't touching the button surface as we don't want to be accidentally bonding things to other things that they shouldn't be. I then used a towel to shield the wider area.

This resulted in something that looked like this:



The next step is to apply the fire. Firstly, ensure that you take all normal precautions around the use of fire. Secondly, make sure that your fire is clean burning. I used one of these because no matter how long I had a go at a piece of tin foil I could not get it to leave any carbon residue. If your preferred fire source leaves any carbon residue (black soot) at all, do not use it.



I did not take photos of applying the fire. My advice is to go slow and carefully get closer with the flame jet until you see the surface change. I made sure to keep the jet moving the entire time and I took several breaks to ensure that I didn't get any part of the surface too hot. You do not want to end up applying too much heat in one place for too long and causing bubbling or smoking, you want just enough for as short a time as possible to get the surface to glass up. By being careful and going slow I was able to get a perfect result with no mistakes, it's a straightforward process so long as you carefully prepare and take your time.

Hopefully it goes without saying to not touch the button or the foil for some minutes until the plastic has cooled.

I'm very happy with the end result:






And the passenger side:





I don't need to do the rear seats as they already look perfect, so this job is done!

Thanks for posting. Great job

[karter16]

I took a small, and carefully controlled amount of flame to the buttons on the front seat belt latches today.

First up - please note that this process works to remove white oxidation and restore the red colour, but it will not work if the surface of the plastic has degraded too far. do not do this if you have any breakdown of the surface of the button.

To begin with I carefully cleaned the surface of the button. If you're going to heat up the surface of the plastic you do NOT want any dirt, skin oils, grime, etc. to be on the button. To ensure that I cleaned this well I used a small piece of magic eraser (note that magic eraser is abrasive and wouldn't normally be recommended on car surfaces, however in this case because we're effectively resurfacing the button the slight abrasion doesn't matter and helps make sure that all the dirt is removed). For the cleaning step I used the magic eraser with warm water with dish soap in it and gave the button a good scrub (be careful to not let water get down into the latch), making sure I worked carefully around the raised "PRESS" letters. I then rinsed off the remaining soap with several rounds of clean water, before carefully drying the button with paper towel. I then left it a few minutes to ensure all moisture on the surface of the button had evaporated.

Next step is to carefully use aluminium foil to shield the rest of the latch. I was very careful to make sure that the foil wasn't touching the button surface as we don't want to be accidentally bonding things to other things that they shouldn't be. I then used a towel to shield the wider area.

This resulted in something that looked like this:



The next step is to apply the fire. Firstly, ensure that you take all normal precautions around the use of fire. Secondly, make sure that your fire is clean burning. I used one of these because no matter how long I had a go at a piece of tin foil I could not get it to leave any carbon residue. If your preferred fire source leaves any carbon residue (black soot) at all, do not use it.



I did not take photos of applying the fire. My advice is to go slow and carefully get closer with the flame jet until you see the surface change. I made sure to keep the jet moving the entire time and I took several breaks to ensure that I didn't get any part of the surface too hot. You do not want to end up applying too much heat in one place for too long and causing bubbling or smoking, you want just enough for as short a time as possible to get the surface to glass up. By being careful and going slow I was able to get a perfect result with no mistakes, it's a straightforward process so long as you carefully prepare and take your time.

Hopefully it goes without saying to not touch the button or the foil for some minutes until the plastic has cooled.

I'm very happy with the end result:






And the passenger side:





I don't need to do the rear seats as they already look perfect, so this job is done!

[karter16]

Change those philips for some sochet head screws, or filister ones (torx) for a factory look.

Yep as I said in my post the bolts are temporary for testing fitment :-)

[maupineda]

Change those philips for some sochet head screws, or filister ones (torx) for a factory look.

[karter16]

Time for an update on the CAD projects.

CAD Project 1: SMG Expansion Tank bracket
I now have a reproduction of the OE bracket that the tank slots into. This is a simplified bracket that doesn't have mounting holes, or the stand off that the original does. That's because I will be mating this to the other part of the bracket that I'm working on. Anyway I'm happy to have this part done. I won't be able to mate the two parts of the bracket together and finalise the part until I actually have the intake in hand so I can ensure everything fits perfectly. So this project will go on ice until then.







CAD Project 2: Adapter for Bosch *101 MAP sensor
And excitingly the adapter for the Bosch 101 MAP sensor is now done! I have a final print in CF-PETG which I will now clean up and bond to the sensor.

Key differences from the last prototype I showed are:
- Return to 1.5mm stand-off. in the CF-PETG 1.5mm is more than strong enough and this allows a bit more of the nose of the sensor to fit into the rail.
- Ever so slightly widened body for better fitment.
- Slight changes to some of the fillets to match the sensor.




And here's some photos of it bolted to the rail (note that it is not bonded to the sensor in these photos). The bolt hardware is temporary just for demonstrating fitment.







I'll be using Loctite 401 to bond the bracket to the sensor. The sensor itself is PBT which can be a bit tricky to bond, however my research suggests that Loctite 401 should be suitable to bond PBT and PETG together (and be heat resistant enough for the application).

I'll post the end result when I have it all sorted.