Black & Tan 332iT

[Bry5on]

Yesterday driving over the mountain to/from Santa Cruz in the heat, the car started to creep up half way between center and the 3/4 dot on the gauge at 60mph in sixth. I wasn’t quick enough to think of turning on the datalogger, but I was able to reproduce it a couple times. Interestingly, I’ve never had a cooling issue at idle or low speed, only above 40-50mph or so on sustained uphill in the heat with AC on. I frequently see 10-15 C across the radiator at idle and closer to 7-10 C on the highway, both with AC on.

I’ve also been doing more research on aero and cooling and have convinced myself that the engine air duct is hurting cooling system efficiency when combined with the CSL intake. In a stock M3, the air intake routes to the air filter box and can only go to two places: 1) the engine or 2) the brake duct. Notably, neither of those two locations are connected to the low pressure zone behind the radiator. When you remove the stock airbox and leave that duct open, you’re effectively giving a path of least resistance for the high pressure air in front of the radiator to route straight behind to the low pressure zone behind. This means that all that air is not only not cooling your radiator coolant, but it’s also slowing down the remaining air that does cool the coolant. So I used some firm closed cell neoprene foam to block up the space and some soft open cell foam to make sure the gap stays well sealed. My first test drive hit two of the routes that are almost guaranteed to tick up the temps (it was 85F ambient) and the needle stayed dead center. So far so good.

Before:


Blocked up:


With softer foam layers:


Some photos of the seal against the radiator support:

[Bry5on]

Yeah I think I'm pretty much at the same point on the continuum as you are. I certainly wouldn't be changing up diff bushes or anything as the NVH would drive me nuts, however from your description and others, there is a pretty minor difference NVH-wise with the solid subframe bushes and I would certainly welcome more sharpness and connectedness. There is also the suggestion (although unsure whether anyone has actually verified it) that solid subframe bushes reduce undesired movement and hence loading on the RACP, which would also be welcome.

I agree with that hypothesis, the carrier/chassis itself should benefit in stiffness from the solid bushings too.

[karter16]

Do you want the car to feel sharper and more connected, or as quiet as possible for highway drives? I prioritized the former slightly above the latter. Easy recommendation of that’s your priority order as well. For me, there’s a very fine line of what’s tolerable. I didn’t like hybrid camber plates and I hated solid RTABs. Most people here don’t seem to notice NVH changes from those, but I would do solid subframe bushings again.

Yeah I think I'm pretty much at the same point on the continuum as you are. I certainly wouldn't be changing up diff bushes or anything as the NVH would drive me nuts, however from your description and others, there is a pretty minor difference NVH-wise with the solid subframe bushes and I would certainly welcome more sharpness and connectedness. There is also the suggestion (although unsure whether anyone has actually verified it) that solid subframe bushes reduce undesired movement and hence loading on the RACP, which would also be welcome.

[Bry5on]

Ugh - I chickened out and did mine in 2017 with new OE bushes. I'll be dropping my subframe when I do the 6 point RACP/RSM brace, and now I'm wondering if I should do this at the same time...

Do you want the car to feel sharper and more connected, or as quiet as possible for highway drives? I prioritized the former slightly above the latter. Easy recommendation of that’s your priority order as well. For me, there’s a very fine line of what’s tolerable. I didn’t like hybrid camber plates and I hated solid RTABs. Most people here don’t seem to notice NVH changes from those, but I would do solid subframe bushings again.

[karter16]

Driving wise, I'm very happy. Wish I hadn't chickened out earlier

Ugh - I chickened out and did mine in 2017 with new OE bushes. I'll be dropping my subframe when I do the 6 point RACP/RSM brace, and now I'm wondering if I should do this at the same time...

[Bry5on]

And following that five minutes of work (the post above took longer than the job itself), I headed to the rear of the car to do wheel bearings and half shafts.

I hadn't heard any grumbling noises from the back, but it turns out that the clicking I'd been hearing may have actually been related to the wheel bearing, as it was pretty shot on the driver's side. This job sucks on the e46, it's actually the first time I've done it. Mostly because the only good way to get the hub off is with a slide hammer. The later cars (and the e39+ I believe) have bolt-in wheel bearings. SO MUCH BETTER. Anyway, here we go. Lighter on pictures, no DIY here.

Left rear, this install tool is pretty slick and makes easy work of pulling the axle in:


And the right rear:


And the fresh half shafts, where you can also see the crappy SSv1 tolerances pointing the exhaust too far to the passenger side:


Overall, this was a smaller change than the solid subframe bushings, but was still an improvement. Now that I think it was the wheel bearing driving the clicking, I'm inclined to say it wasn't worth the $1500 or whatever it was for both half shafts. It's better, but probably not $1500 better. There's not much of the m-clunk anymore, which is nice though! We'll see if it stays that way.

And as a bonus, I finally bit the bullet now that there's a mini with a roam plan - my Starlink Mini showed up. This will be backup in case the house internet goes down (fiber, it never has, even when power is out), or to be used on trips as it can run on anything from 12-48v (including the car's power outlet). Worked great during the test run.

[Bry5on]

Okay, two things today: Steering wheel spacer (easy) and half shafts & wheel bearings (hard). The easy stuff first.

So I'm 6'3" - on the taller side - and also like to have my steering wheel close enough to maintain good control of the car (outstretched arms, wrists on the top of the wheel). The e46 only has about 30mm of telescoping adjustment, which leaves me pretty short of my ideal position. So now that I've got the normal steering column issues sorted, I decided to do something about the placement of the wheel.

I chose to do this in the simplest way I could think of, by making a spacer. What I came up with is three parts: 1) a female spline 2) a male spline and 3) a 3D printed plastic 'extension' to keep things looking tidy. We'll be bringing the steering wheel forward 32mm. Here it is in CAD:


And in real life:



I'd been wanting to learn how to use the EDM, so I decided this was the perfect project. First, I cut off the splines of my old steering column:


Then dropped it into the VMM to get very detailed dimensions and a photo of the tooth profile I could use to design a spline pattern:


Then I designed the CAD, some flat pattern DXFs, programmed CAM into the wire EDM and loaded some 15-5 stainless into the machine - it took a couple tries to absolutely nail the zero-play geometry:




And the finished splines, showing off the barely visible (.0004"/.01mm gap!) pattern, with keying feature to maintain alignment:


So we're on to the install (not pictured is extending the harness, temp harness pictured) below. First step is to remove the spring loaded metal clocking lock at the bottom of the wheel, which only functions to keep the plastic from spinning when the steering wheel is removed. Then install the female spline piece onto the male shaft:


Then install the 3D printed spacer (plus two additional rubber grommets, not pictured):


Then the male spline (following the matching key):


And finally the steering wheel:





That's the steering column spacer, it's about a 5 hour runtime on the machine but super accurate. It works absolutely great and really helps the driving experience. I feel like I have much more confident control of the car now, just like I felt after upgrading the driver's seat. The only downside is that you have to reach farther to get to the turn signals, windshield wipers (and in my case, DSC button . I've been running a not-perfect prototype for a couple weeks so I've already gotten some decent seat time with this one.

[Bry5on]

I'm really interested in how that turns out!
Last year I refreshed pretty much everything under the car, front and rear, including new bushings, mechanical lsd, propshaft refurbished etc.. For the half shafts I only repacked the inner CVs with grease (was liquid as everyone is saying), the outers I haven't done yet. Now I also get a slight clunking from the rear left, especially in left turns. I suspect it's the outer CV from the left half shaft. Just contemplating if repacking the outer CVs with grease and changing the wheel bearings will be enough, or if it's time for new driveshafts. Unfortunately BMW raised the price here in germany, from 650€ to 850€ per side.

Yeah they’re expensive now! The new ones came in, made by GKN in 2023 and 2024. I’m hoping these eliminate the last of the clunk along with fixing the left wheel clicking. I never bothered repacking the outers when I replaced the inner CVs.

It’s also worth noting that the solid subframe bushings really helped with the clunking between shifts. The previous owner had installed urethane subframe bushings, which is the worst bushing material, but I am still surprised by how much tighter the rear end feels. The subframe was definitely rocking before during shifts.

[rtrules]

New half shafts and rear wheel bearings are on the way as one of my outer CVs went and is clicking incessantly on right turns. That and the play, especially on the right side, in the inner part of the shaft even with new inner CVs is still pretty bad. I figure the play must be in the splines, so I forked out the dough for a pair of new ones. Still chasing that M-clunk.

I'm really interested in how that turns out!
Last year I refreshed pretty much everything under the car, front and rear, including new bushings, mechanical lsd, propshaft refurbished etc.. For the half shafts I only repacked the inner CVs with grease (was liquid as everyone is saying), the outers I haven't done yet. Now I also get a slight clunking from the rear left, especially in left turns. I suspect it's the outer CV from the left half shaft. Just contemplating if repacking the outer CVs with grease and changing the wheel bearings will be enough, or if it's time for new driveshafts. Unfortunately BMW raised the price here in germany, from 650€ to 850€ per side.

[Bry5on]

Have been doing some reading, playing round with TunerPro etc. getting up to speed on how this all hangs together. Interestingly my (standard Euro M3) binary has some very different values in the VANOS target value tables compared to the standard "M3" tables that you show here (Particularly on the exhaust side). I could understand some differences given mine is a Euro M3, but there appear very significant differences in places 🤔 (unless I'm wrong that the highlighted column headers in your spreadsheet mark the actual values). Are the M3 tables you show above from a US-spec binary? or some other source?

My tables for reference:

I’ll have to expand out the euro table, it’s really difficult to see from tuner pro directly as the interpolation targets change. I’ve based mine on a US M3 so indeed there might be some differences due to the headers. I’ve been thinking about doing the diff between US and euro tunes and trying a version of the mullet specifically for euro/aftermarket header cars as I do expect headers to change where the ideal cam targets are. Maybe this was the motivation I needed

edit: Caveat, US tune also is designed for 91 octane that we have here in the states to prevent pinging. So the euro tune may not work for all octanes here. That’s the other reason I baselined the US tune.

[karter16]

Intake cam timing (CSL, M3, Mullet):

Not a huge change on the intake side, but there's a big change at low rpm, high load that's notable.

Exhaust cam (CSL, M3, Mullet):

Look how different the exhaust cam operation is at low RPM!! That big step change in the M3 map about 1/3 of the way to the right? That's 2700rpm! The data, it speaks to us.

Have been doing some reading, playing round with TunerPro etc. getting up to speed on how this all hangs together. Interestingly my (standard Euro M3) binary has some very different values in the VANOS target value tables compared to the standard "M3" tables that you show here (Particularly on the exhaust side). I could understand some differences given mine is a Euro M3, but there appear very significant differences in places 🤔 (unless I'm wrong that the highlighted column headers in your spreadsheet mark the actual values). Are the M3 tables you show above from a US-spec binary? or some other source?

My tables for reference:

[Bry5on]

Holiday weekend, had the day off. In went some bimmerworld (not raised! See all my geometry posts throughout this thread) solid subframe bushings and a new fuel pump. The juxtaposition of the easiest job ever (the fuel pump) versus the hard job of subframe bushings while on your back was interesting.

I threw the bushings in the freezer for a couple days before doing the job, I don't think it made much difference though.

Pretty sure I was using that tool wrong for the rear two bushings, but oh well, it worked out in the end.

Driving wise, I'm very happy. Wish I hadn't chickened out earlier. The rear definitely feels more rigid and taut and has maaaybe the tiniest bit more tire noise than the AKG 95A bushings that were in there. The rear feels more planted down, the dampers feel like they're doing a better job, and there's some oscillation that's gone on throttle application and shifting. There's just a little bit of a harshness that was added, but not bad harshness - not even in the order of magnitude realm of the harshness that the solid RTABs added. These will certainly be staying, overall a great upgrade that modernizes the car much like the newer M cars now are.

New half shafts and rear wheel bearings are on the way as one of my outer CVs went and is clicking incessantly on right turns. That and the play, especially on the right side, in the inner part of the shaft even with new inner CVs is still pretty bad. I figure the play must be in the splines, so I forked out the dough for a pair of new ones. Still chasing that M-clunk.

And since I was in there unbolting the subframe bushing/brace, a photo of where I located the rear PDC speaker (under the mounting bracket for the TV tuner) as I don't think I ever published that here:


And last, all that sound deadening work I did in that photo above didn't do nearly as much as the little bit that I did in the wheel wells and rear quarters recently. Word to the wise.

[puma1824]

Well I didn’t remove anything except the holes I added a probably five pounds of sound deadening and then replaced the fender insulation with a hole-less ( technically heavier) part. The exhaust did seem a bit quieter, hard to tell on the quick drive I did honestly.

Oh you kept the existing and added the deadening material. At first glance, I thought you just replaced it. Thanks for the info

[Bry5on]

I really like how you've taken the extra steps. Do you know if your noise reduction is either quieter and/or lighter than the existing dampening? I'm entertaining doing the same to my touring while I replace those 6x9 speakers.

Well I didn’t remove anything except the holes I added a probably five pounds of sound deadening and then replaced the fender insulation with a hole-less ( technically heavier) part. The exhaust did seem a bit quieter, hard to tell on the quick drive I did honestly.

[puma1824]

I really like how you've taken the extra steps. Do you know if your noise reduction is either quieter and/or lighter than the existing dampening? I'm entertaining doing the same to my touring while I replace those 6x9 speakers.