Black & Tan 332iT

[Bry5on]

Red calipers are on, bled, and not making any humming noises. I swung by heinzboehmer's place to borrow his pressure bleeder and confirmed that his calipers are also showing signs of spinning pins. Hopefully his don't get so bad to the point that they're making as much noise as mine were!

Interestingly, after cleaning the bores, it appears that they're stepped and the factory used some sort of adhesive or gap filler as well. Clearly, it did not work. I hit the pins and bores with 400 grit sandpaper, followed by acetone then IPA wipes then mixed up some high temp Hysol EA9340 epoxy. I made sure to coat the bore and pin surfaces completely and pressed them in to avoid any air pockets. Following that, drove in new split roll pins and put them on the desk heater to cure for 2+ hours at 140F.






Some nice relaxing YouTube content while I worked away and let the EV charge..


They're pretty crap condition but will tide me over until I repair the black ones. Red is just too loud for this car, I'll be glad to get the black ones back on. So far, so good - no humming on the highway. The pins in the black calipers are *very* loose, and I'd wager that it's just a matter of time for every car running these calipers until they loosen up and start making noise.

[Bry5on]

Boy am I glad I found your thread. Was searching for 17x9 fitment for my S54 touring and came upon your post about the +52 ARC-8s, and eventually found my way here. I'm still in the midst of the swap, lots to unpack here, thanks for sharing!

Good luck! Yeah the setup I've got is definitely the hot ticket for the M3 suspension on the non-m body. You'll probably need to flip your strut hats (or run camber plates) to get more than -1.5 degrees of camber to keep the front tire under the fender.

[SkunkWorks]

Boy am I glad I found your thread. Was searching for 17x9 fitment for my S54 touring and came upon your post about the +52 ARC-8s, and eventually found my way here. I'm still in the midst of the swap, lots to unpack here, thanks for sharing!

[Bry5on]

I haven't seen anyone mention that lower bushing before. What was a sign that it needed changing? Play in the steering wheel besides turning it left and right?

Grab your steering wheel with a firm grip at 3&9 and pull up/down. If it moves, there’s play in the bushings. Based on the design, if you’ve got white ones, I’d recommend changing them to the new style. You’ll need a small pry bar, it’s kind of a bitch to get them in.

[Ubaderb]

Overall, this is a fantastic change to the car. It really makes the whole car feel firmer and much more direct, and actually reduced! vibration from the steering wheel. Well, it might be more accurate to say it added a slight bit of high frequency feedback, but removed the sloppiness and low frequency vibrations of the stock parts. Steering inputs are way more direct and controlled and it’s my opinion that the car should have come from the factory this way. I’d say this is in my top 3 for changes I’ve made to the car, 1 being seats, 2 being the Slon and v-brace chassis stiffening, with 3 being the more direct steering. Hope this encourages more folks to make this change!

I haven't seen anyone mention that lower bushing before. What was a sign that it needed changing? Play in the steering wheel besides turning it left and right?

[Bry5on]

Rainy day today, so I did a little work on the car again. Today’s task was to tighten up the steering with two specific changes: 1) New lower steering column bushings and 2) an LPSR solid steering shaft

The lower column bushings made a big difference with how perfectly solid the steering wheel is now placed in my hands. The new bushings were actually a different design and shape than the loose ones that came out, and I expect these to stay tight and perform better over time. This was a surprisingly big change to the firm feel of the car in the hand.




Second was the LPSR steering shaft. Because this shaft doesn’t have a collapsible section anymore for installation, it is slightly shorter than the original, but the column has plenty of travel to accommodate this. I was also concerned that it was clocked differently so I purchased a spare plastic cover for the rack splines and trimmed the alignment fin off to allow any clocking at the rack side. To install, I locked the steering column in the center aligned position, and was then very careful to not disrupt the rack’s position as I removed the stock parts and installed the new ones. The result was a perfectly aligned steering wheel on the test drive. Here’s what it looks like installed.


Overall, this is a fantastic change to the car. It really makes the whole car feel firmer and much more direct, and actually reduced! vibration from the steering wheel. Well, it might be more accurate to say it added a slight bit of high frequency feedback, but removed the sloppiness and low frequency vibrations of the stock parts. Steering inputs are way more direct and controlled and it’s my opinion that the car should have come from the factory this way. I’d say this is in my top 3 for changes I’ve made to the car, 1 being seats, 2 being the Slon and v-brace chassis stiffening, with 3 being the more direct steering. Hope this encourages more folks to make this change!

[Bry5on]

I got to milling out the roll pins on the second set of 996 calipers. These ones also had pins that had spun/were spinning. The failure mode is that the roll pin collapses in the pin’s machined groove and some combination of vibration, heat, and a mismatch in pin/caliper coefficient of thermal expansion causes them to start working loose.

I’m surprised nobody has mentioned this online, there is absolutely no way that I’m the only one who has experienced this failure mode .. twice. Check your 996 calipers folks. What a shit design.

The roll pin bores are 3.05mm ID by 12mm long, and the pins are 3mm OD x .6mm wall x 12mm length. Available in spring steel from your friendly McMaster warehouse in qty 200.

I’ll be installing the loose pins with a high temp epoxy followed by fresh roll pins. We’ll see how it does on the red calipers while I rework the black ones.

Action shots of milling out the roll pins on the three that had spun in the red calipers:

[Bry5on]

Update: the RTV goobering only lasted a few hundred miles. Heinz and I stumbled across a set of red 996 calipers at the local junkyard, so I’ll machine those and swap them so I can take my time on the repair work of these black calipers. A whopping $100 for the set, and they’ll be going to another forum member once I’m done temporarily using them.


Also got some leather from a natural brown e46 to finish trimming the isofix cover that I haven’t been able to find. Big score. Seen packed inside the inside-out armrest here

The reason I was there was to get a steering angle sensor harness. I made a jumper harness that brings CAN more permanently (but removable) to the OBD connector. Works great.


And I got back under the car again to do the shift pivot bushing that broke after 20k miles. Replaced the rubber bushing, cup, pivot and ultrasonically cleaned the shifter parts before also doing a flexdisc and center support bearing. Man a fresh set of factory shift parts feels great.

[Bry5on]

We hit a nice milestone lately, and I FINALLY got a photo like this. I've missed this opportunity in every other car I've owned. Not this time.


And you'll note that the car is running nice and cool. I did swap the faulty Nissens radiator for a "Modine" (NSF) and the datalogs are showing a steady state improvement of temperature across the radiator on the highway. I was seeing 5-10C on the highway at ~65F with the Nissens and I'm seeing 15-20C under similar conditions with the Modine. I'm hoping that I've finally licked this overheating issue.

I do need to return this one as a core, so sadly we won't be able to open it up and see if there was internal blockage. Before returning it, I did get a chance to borescope it on the inlet side and didn't see anything unusual. That and I can confirm that the M3 radiators are single-pass radiators. Most online resources I could find seem to claim they are triple pass - not true.

Enjoy this crappy photo of the fresh radiator installed:


I've also been having a very strange issue with my 996 calipers that I haven't found any documentation for online. The pins that retain the pads in place are LOOSE and vibrate/spin on the highway making an incredibly loud humming noise that goes away the instant you touch the brake pedal. Three of four of the top pins on my front brakes were loose - you could spin them by hand. This likely explains why Porsche killed the roll pin retainer design in favor of a bolted in pin design.

In any case, I bond prepped and goobered some copper very high temp RTV to keep them from vibrating and this seems to have done the trick. If this doesn't work, I'll pull them off, mill out the roll pins, then install the pad retainer pins with high temp epoxy and new roll pins. A pain in the ass to be sure, so I'm hoping I don't have to do that.

Photos of the bandaid fix:


Otherwise, just doing the wagon things

[Bry5on]

Do they make a smaller display that would fit in the SMG area? That would be pretty slick-- especially if it can be turned off when not in use (I kind of get OCDed about cluster asymmetry).

Yep, there’s a 1.54” display that uses the same chip and resolution. And yes again the display can be dimmed or turned off completely. I’m working on this next with my spare cluster. Display is already en route.

[George Hill]

I would think 5* is not enough of a delta. I feel like when we were last logging this info and chasing a bad radiator (CSF), we ultimately found after putting a OE BMW rad in it that we had a 10-15+/-*c delta. I think on that car we were seeing 94 at the engine and then 82 at the rad outlet, I don't think it ever got into the 70s.

[Obioban]

Do they make a smaller display that would fit in the SMG area? That would be pretty slick-- especially if it can be turned off when not in use (I kind of get OCDed about cluster asymmetry).

[Bry5on]

So I bought a Nissens radiator during the great Modine stock-out of 2022, and it turns out I paid the price. This radiator will be going back under warranty, and I’ll see if I can get away with keeping it to dissect for science. All cooling problem signs are pointing to the radiator as it’s failing on the inlet seam. Likely internal blockage.

[Bry5on]

I've spent the week datalogging and mapping some of the CAN parameters, learned a bunch!

On my cooling system: I'm seeing anywhere from 5-10 degrees C between coolant temp and radiator outlet temp on 65F (18C) days here in CA while driving. This seems rather low, although I have nothing to compare against. Has anyone got any information on what I should be seeing here? Ironically, cooling performance seems best at idle, where I see about 15C delta. Maybe this triple pass radiator from Nissens is acting more like a single pass radiator? George Hill ?

So far, in k-bus/CAN and now my datalogs, I've mapped:

K-bus
* Engine speed (RPM)
* Engine load (mg fuel/stroke)
* Mass Air flow (kg/hr)
* TPS position (%)
* TPS target position (%)
* Air intake temp (C)
* Coolant Temp (C)
* Radiator Temp (C)
* Oil Temp (C)
* Ambient Temp (C)
* Exhaust Gas Temp (C) ------- Anyone know the correct scalar for this on the k-bus??
* Battery Voltage (V)
* ECU Master and Slave voltages (V)
* Ambient pressure (mbar)
* Relative open throttle cross section (%)
* Throttle pedal positions 1 & 2 (%)
* Analog input configured for Wideband O2

CAN bus
* Cruise control buttons (to control the Gauge.S interface)
* Cruise control status (to inert the buttons while cruise is on)
* Speedometer (kph/mph)
* Engine speed (RPM)
* Engine theoretical torque (%, includes torque going to accessories)
* Engine torque (%, just motive torque)
* Steering Angle (degrees)
* Brake pedal status (1/0)
* Clutch pedal status (1/0)
* DSC off (1/0)
* DSC actively in control of car (1/0)
* MSR/Ignition cut DSC torque reduction (%)
* Throttle cut DSC torque reduction (%)

Calculated parameters
* Gear (1-6, 0)
* Smoothed G acceleration, average of last 5 datapoints (currently using Gauge.S built-in accelerometers)

CAN bus still in work
* Lateral DSC acceleration (G or m/s^2)
* Longitudinal DSC acceleration (G or m/s^2)
* Yaw
* Individual wheel speeds

Since I made a harness to connect this to the OBD port, this device can be plugged into any e46 to log k-bus parameters, and if you wire CAN Hi and CAN Lo from the steering angle sensor to your OBD2 plug, can log everything above, just by plugging in the device. Temporarily I have it adhered in front of the cluster, but I'm looking into getting a smaller 1.54" display that will fit everything into the SMG/automatic insert section of the instrument cluster. Really impressed with this! Hard to grab good photos because the camera catches the refresh rate, here are a few examples:






General update on the car, it's doing its job as a car just great, and I'm reminded that it's an s54 because I've started to smell a faint burning oil smell from the cabin again. Guessing it'll be the valve cover gasket this time.

Plus the view out the back with a big bike:

[nuc1]

More updates on the steering shaft later - in the meantime, I've been busy working on improving datalogging by using Gauge.S. I've successfully brought CAN to the OBD port and am now using the CAN cruise control buttons to operate the device that logs parameters on the CAN bus and the K-bus. Really cool piece of kit, I might go so far as to permanently install it somewhere hidden, like in the ash tray or something.

Lots of logs with lots of data available, here are a few:

https://datazap.me/u/bry5on/gauges11?log=0&data=1-21

https://datazap.me/u/bry5on/gauges9?log=0&data=1&solo=5

https://datazap.me/u/bry5on/gauges-8...ta=4-25&solo=2

That is really cool. Defintiely going to look into this.

Mike