Cockroach Individual M3 5/15/2026 Floating rear rotors, steering coupler, dyno

[samthejam]

Someone did get a pic of my M3 at Road Atlanta

Untitled by Sam DaJam, on Flickr

So the overheating situ for on track...

On the street the car has absolutely zero issues with temperature, and if it's below 85+ the car was on track. Anything over that 5 laps, absolute tops. Usually 3-4. This is unacceptable, by this point it is at 3/4 and it will keep climbing. If it equalized at 3/4 I'd give it a pass but it wasn't.

To address this prior to this post:

- replaced the front ducting for the rad
- replaced the radiator with a 2016 date Modine used radiator
- replaced the thermostat with a lower one 70C
- water wetter/more water mix
- added the factory undertray
- added all the factory fan shrouds (I only had the main one)
-bleeding it multiple times, jacked up front end and other tricks

and it passed a exhaust gas test for the coolant and isn't using any.
Fan clutch can be heard moving a lot of air with raised rpm and it destroys a roll of paper towels at idle.

There were no real obvious improvements with any of those changes. The lower temp stat resulted in longer warm ups and lower operating temps cruising around under 60mph. Once I was on the highway with the A/C on gauge would be at the middle. Which I always thought as odd, as the increased airflow should bring it down.

Out of ways to optimize the stock system further, I got a Koyo Radiator and cleaned out the A/C condenser.

That is the not the 2016 Modine, I had in but the other Rad I had that basically came with the car. Just have it there for comparison.

Untitled by Sam DaJam, on Flickr

Untitled by Sam DaJam, on Flickr

I just got some simple green coil cleaner and a regular garden hose trigger nozzle thing.

Untitled by Sam DaJam, on Flickr

Can't see the shiny thing hidden under everything but its there.
Untitled by Sam DaJam, on Flickr

Now I fully believe the stock system should be capable of keeping a car cool. My fathers did great when he had it, as a street car and as a trackcar with deleted A/C. He never had an issue. A Genuine Rad is now $700~, and I had already tried the best used one I could find.

I figured it would be time to try a Koyo and see if a result, worst case I have a radiator without end tanks to break off.

So the results,

The car by the gauge, and by the OBD2 reading is running WAY Cooler when moving. I have yet to see it go past 82C on the highway on a hot summer day. I feel like I can say the cars cooling system has increased in removing heat now with airflow, which was what I had been chasing to see an improvement. With the low temp stat, it is much more evident that it seems to be cooling better. I can't say this will give me a track session but this is the most progress I've had on seeing improvement in the system on the street.

Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr

Now as anything goes, increased radiator cooling usually comes at the drawback of this radiator probably is harder to get air through it, since it is slightly thicker. So far that hasn't been an issue at low speeds, and not at idle yet. When August hits, I'll know for sure.

Untitled by Sam DaJam, on Flickr

Untitled by Sam DaJam, on Flickr

I also went to take it to work Monday and was greeted with the battery light staying on. Luckily I had a spare, looks like a BMW reman from 2007.

Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr

The original alternator, had absolutely no brushes left. I unfortunately didn't check the brushes on the one I put in, but way she goes. I should be able to put brushes in the bad one, and that should fix it. I have a local guy that can also go through it as well if needed.

[samthejam]

Let me know if you ever want to get rid of 4 of those SSRs. They look so boss. Cool to see one of these cars still really used as a dual purpose street/track car. Reminds me of myself 10-15s ago with old Hondas and stuff.

Probably going to diamond hands these haha, is some sentimental value since they're takeoffs from a childhood racecar and they're a great wheel. They've had a lot of hours on them from their prior life and how I am using them. So I know I'll need the spares I have.

Glad you're enjoying following along in my shenanigans.

[discoelk]

Let me know if you ever want to get rid of 4 of those SSRs. They look so boss. Cool to see one of these cars still really used as a dual purpose street/track car. Reminds me of myself 10-15s ago with old Hondas and stuff.

[samthejam]

It's officially been one year with the car, 28,000 miles in that year.


I actually washed it!
Untitled by Kurvenkamph Motorsport, on Flickr

I did Road Atlanta again, I did a bad job planning. It came up a week quicker than I thought. So I was gonna have to do the BBK there. Which I was nervous about for this reason. So my wife and I left early, spent a night in NOLA in the french quarter. Got to Atlanta early Friday to do the BBK.
Untitled by Kurvenkamph Motorsport, on Flickr

Idk what other monkey worked on this car, but brakelines are like a sacred thing to not fuck up for me. When I initially tried to change these, I could not get them loose. Luckily with jayjaya29 help they loosened right up.
Untitled by Kurvenkamph Motorsport, on Flickr

He also trimmed the heat shields for this, and donated some stuff from his parts car and bent the hardlines into their homes so that is all correct now.
We were left with this a Stoptech ST40 BBK. I also installed some NOS softlines from Stoptech and NOS PFC 01s.

Untitled by Kurvenkamph Motorsport, on Flickr
Untitled by Kurvenkamph Motorsport, on Flickr
Untitled by Kurvenkamph Motorsport, on Flickr

Track driving is not a stopping contest, but the confidence this setup gives me now has been amazing. I am no longer scared of brake zones in this car, so I can be more brave experimenting.

Untitled by Kurvenkamph Motorsport, on Flickr


Car is still getting hot. This issue is really pissing me off. I will do a separate post about that or maybe even thread. It is only replicatable on the track at full pace driving, 85 degrees+. The other issue is the LR shock I rebuilt, despite not leaking did fail. I believe I go the dividing piston in wrong spot and it adjusted itself, as well as overfilled it. So when it moved down there no air near the top/most of its stroke. So my LR damper was struggling, I was able to get the shock settings good enough to drive it. I wanted to perservere and drive through the issue and I did to break a sub 1:40. Also not really a fan of the ECFs.


Untitled by Kurvenkamph Motorsport, on Flickr
After that I did try the Bilsteins, and it makes the car much easier to drive as well as not beating me and the car up.

However, I really like the ability to just have turn in sharp enough to hurt myself. I don't like trail braking and dealing with understeer. I really enjoy just putting the car in a slide and holding it, so while the Bilsteins will work in the long run I hope I am not stuck with them.

Untitled by Kurvenkamph Motorsport, on Flickr


I spent about 3-4 hours assembling the AST upon returning home from my 13 hour drive. I believe I have it right now. So that issue I'm not too terribly worried about, it's back in car. Time will tell. However the cooling system getting that sorted for 20 minute sessions of driving how I like to will need to be figured out. We did try a stock undertray this weekend.

Overall an absolutely amazing trip.
Untitled by Kurvenkamph Motorsport, on Flickr

Here is video of the best lap:

[/QUOTE]

[samthejam]

I was able to repair the AST shock, or it hasn't leaked for the past 200 miles. We'll see how long that stays. More about that here, that was my favorite automotive side quest by a huge margin in a long time. More about it here.

https://nam3forum.com/forums/forum/main-forum/e46-2001-2006/292889-before-i-lose-my-mind-ast-4150-setup-opinions

Untitled by Kurvenkamph Motorsport, on Flickr


I also got the 70C stat in, from my current observations it will not do any miracles. It definitely increases oil warm up time. The car will need a better rad, however the thermostat will help me know if I'm going in the right direction for certain thermal conditions and also allow me to bring the cooler temps down more than with stock thermostat for cool down laps before I get on it again. Probably will try a Koyo rad first?

AC OFF
Untitled by Kurvenkamph Motorsport, on Flickr

AC ON
Untitled by Kurvenkamph Motorsport, on Flickr

If it's 90+ or greater it's just in the standard buffer range cruising or at idle.

Untitled by Kurvenkamph Motorsport, on Flickr

[samthejam]

I have a used BBK on the way Stoptech ST40, looks like 355x32mm rotors. I am archiving the part numbers I might need here for reference as I know availability is getting rough.

Just want it it to be saved somewhere, I can get to on my phone.

Looks like the kit is:

https://www.bimmerworld.com/Brakes/BMW-StopTech-Big-Brake-Kits-BBK/StopTech-Big-Brake-Kit-Front-M3-E46-355X32-ST40_7.html

83.137.4700

Aerohats:
37.137.7415

355x32mm Slotted Left Aerorotor with hardware:
SRT31.737.1101.99

355x32mm Slotted Right Aerorotor with hardware
SRT31.737.1102.99

Girodisc Brake Rotor Set with Hardware:
- GD355.32.52

https://www.bimmerworld.com/Slotted-Rotor-Rings-Girodisc-355x32.html

Pad Info:
Hawk Pad Shape: 650
PFC Pad Shape: 447
Pagid: 1204

https://www.bimmerworld.com/ssearch.html?query=st40+Pads

" FMSI D372, D447, D609. Fits:
1994-98 Audi RS2
1994-96 Ferrari 456 GT Coupe Rear
and many Porsche models, including:
1996-98 911 Carrera 4 rear
1991 911 Turbo
1986 928 S
1987-91 928 S4
1990-91 928 GT
1989-91 944 Turbo
1992-95 968 Sport
Also fits the Stoptech ST40 caliper.

| Brand | Part # | Description |
|-------------|-------------------|--------------------------------------------------------|
| PFC | 0447.08.17.44 | 08 Compound – Endurance racing, low wear |
| PFC | 0447.11.17.44 | 11 Compound – All-purpose racing, flat torque |
| Hawk | HB141U.650 | DTC-70 – Max bite, aggressive track use |
| Hawk | HB141G.650 | DTC-60 – High torque, better modulation |
| Hawk | HB141N.650 | HP Plus – Street/track hybrid |
| Hawk | HB141B.650 | HPS 5.0 – Performance street pad |
| Ferodo | FCP372H | DS2500 – Street/light track, refined feel |
| Pagid | U1204 14 | RS14 – High bite, ceramic-based race pad |
| Pagid | 63-910-0609 | RSL29 – Endurance compound, consistent wear |
| Porterfield | AP372-R4 | R4 – Full race pad |
| Porterfield | AP372-R4S | R4-S – Street/autocross pad, rotor friendly |
| Centric | 105.06090 | Posi Quiet Ceramic – Low dust, street use |
| StopTech | 334.0609.17.0 | SR34 – Full race pad, high bite, low wear |


I'm pretty sure there is a spec series, not sure if its a 928, 944, or 968. "

PFC 11:
-0447.11.17.44


Brake Line Set for front:
950.34005 (this is wrong this is for stock calipers)
950.34000 (this is for st40 kit)

Caliper Rebuild Kits:
They seem available but you need to know if long or regular piston? Different diameters from 26-40mm?

https://www.zeckhausen.com/catalog/index.php?manufacturers_id=2&srsltid=AfmBOoreRSya8 OkJPSKmsWSSIvjCikHMGOAQIwcrM2lIpgm9mnzTwUEB

Caliper Bracket part #s:
36.137.7419

https://nam3forum.com/forums/forum/classifieds/members-parts-for-sale-wtb/e46/251924-stoptech-front-st40-bbk-new-girodisc-rotors

Caliper Assemblies in Black:
ST-40 caliper, 38/44mm pistons, black, 32mm wide, trailing R (ACS.43E.1154)
ST-40 caliper, 38/44mm pistons, black, 32mm wide, trailing L (ACS.43E.1153)

Hardware:???????????????

https://images.carid.com/stoptech/info/pdf/catalog.pdf

[samthejam]

One of my fave build threads by far, all the pictures and background make the whole thing so much more "real"

Glad you are enjoying following along!

[nextlvel]

One of my fave build threads by far, all the pictures and background make the whole thing so much more "real"

[samthejam]

Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr

Did some research and found some Porsche Bilsteins that fit. I did the same thing for my E28 since it did not have much aftermarket support, Porsche shocks are great to adapt as they are valved fairly stiff since Porsches have an engine in the back. They are also shorter, but the bumpstop engagement looks perfect. I went with the stiffest one I could find as I have a stiff rear spring. Older 911s have a lot of different options for OTS Bilsteins.

Just got back from a test drive, best the car has ever felt. Firm but supple ride, way more rear grip. Just feels good. I had to get some adapters but got lucky with scamazon.

[samthejam]

Dude, run 17s. So much cheaper. 275/40R17 660s are $1100 shipped from Tire Rack.

I'm not against it, just using the wheels I have

[bigjae46]

Dude, run 17s. So much cheaper. 275/40R17 660s are $1100 shipped from Tire Rack.

[samthejam]

Howdy y'all another update.

So I ended up getting the Continental Extreme Force Contact, 275/35R18. They were on sale. Fuck modern 200tws tire sizing, they must be like 285s. My last set of direzza were "265s" but look a lot different than the Rs4s that are mounted on same wheels. Anyways, so I took out the spacers not a big deal but fucking annoying. I should've got the 265/35R18 RT660s that were also on sale but wanted something a bit more endurance focused for this go around on tires.

Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr

During that I noticed my RR balljoint was fucked. Had quite a bit of play, explained why the car was so loose last time I took it out.

Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr

So I ordered a toolset from Amazon and Lemforder Balljoints, was very happy to see Made in Germany on the Box!


My friend with less than a weeks notice suggested we go to FD to spectate Road Atlanta, and I realized I hadn't taken a day off yet this year. I also wanted to help jayjaya29 finish his S54, we are pretty close talk to eachother almost everyday about our cars, life etc.. The progress had naturally slowed down with his new child, and he needed the car mobile to maintain his other cars. He has helped me out in so many ways the least I could do was a weekend slam to get it out on its first test drive. So the plan was, get car aligned Thursday. Leave Friday, do the weekend stuff and cannonball home Monday a standard Atlanta trip for me.

Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr


Not a big fan of FD, but a big fan of supporting this amazing track and people using it. It was a good time.
Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr


Now back to the car. Before I left, I saw the LR shock was leaking there was oil up the 3 or 4th threads. Which sucks. We had the car packed down with 3 people, luggage, all my tools, spare tires etc. The shock did not make it. When we arrived to Atlanta it was dripping oil onto the floor. It had a slight knocking noise under big bumps, I felt it during a driver swap sleeping in back seat. The car was also pulling to the left, Lins Automotive was open and by the track so I stopped by to get a last minute alignement. I called Friday ahead for notice and they were very cool about it.
Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr


Other than that, no real issues on the trip. Thing pulls strong, we had some stretches of open roads still pulling up the factory Vmax that is deleted, but didn't have the balls to go past it.
Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr

When I left ForumlaD, one of the drift shops by there had $100 dyno pulls. So I pulled in and let er eat. They strapped down the factory lower camber arms, so pretty sure rear alignment moved a bit but luckily they didn't bend visually.

Untitled by Sam DaJam, on Flickr

The guy at the shop said they usually dyno at 260 there which seemed very low, but I had no baseline so who knows. Anyways Pretty happy with that, I am told if I do a cold air intake like AFE or something there is some more. However K.I.S.S, stock airbox is very serviceable.


Back to the shock, by the time I was back home in Louisiana. The noises it was making was not good, and the last stretch to my house in Houston was rough but we made it.

Untitled by Sam DaJam, on Flickr

The shock is quite rust proofed. I need the car in less a month at Road Atlanta and I want it up quick and cheap. I think I have come up with a solution, I will post that next if it is successful. Trying to save up for MCS new or find a good pair used so want to just get moneys worth out of this set.

That puddle of oil off to the side is from just setting the shock over. It still has gas pressure but it is hemorrhaging fluid.

It got 22mpg with me using cruise going 80-90. My friend drove it briefly on the way up and he got 24mpg doing 60-70.

[bigjae46]

Poly is trash. Stay OE rubber or go with the Turner spherical.

[samthejam]

So these Bimmerworld TrackCABs have been pretty terrible. They just don't hold up well for me. Even if installed flush they will work their way out and eventually start to wear a groove in them.

Remember how I just did these a couple months ago?

Untitled by Sam DaJam, on Flickr

Well here is the driver side.

Untitled by Sam DaJam, on Flickr

Already a groove and itll do a popping thing under braking. You can't replicate it with a pry bar, its fucking annoying in daily use until it gets really really bad. . Luckily a set of used FCABs came up here on the forum, a set of AKG ones already installed in some housings.

Untitled by Sam DaJam, on Flickr

Installed those last nights laying in the rain in the driveway, hopefully these will hold up better. I also bent back out the heat shield for passenger side FCAB. I think that whole shield will just need to be replaced.

[samthejam]

Untitled by Sam DaJam, on Flickr

So my tire situation was in pretty dire shape. I asked around on facebook and SQ13 had some older 265/35R18s. They're older Acceleras like 7 years old but tread, so perfect enoough to get me around in interim until I can get a new set of 200tw.

This was an adventure in itself getting them back here.
Untitled by Sam DaJam, on Flickr

Then I stacked the wheels in...
Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr

I have a bunch of extra SSRs but they don't match.

Untitled by Sam DaJam, on Flickr

I really liked the silver in the front. More on that later.

Next I wanted to tackle the ducting so went to my friend Alejandros house, and he had something I could use as well as a bunch of other hardware and little bullshit.

Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr

I could not stare at the mistmatched wheels any longer, so I got the spray can out.
Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr
Untitled by Sam DaJam, on Flickr

Untitled by Sam DaJam, on Flickr

Untitled by Sam DaJam, on Flickr


I also realized I was losing my mind driving the car making changes trying to feel differences. I started to just wonder if the methodology I was using, to tune it which was mainly adjusting ignition timing because that's what I saw in the other tune. This just seemed like the wrong approach with the amazing vanos system on this engine. So I gave up and decided it was best for my time and sanity to outsource this.

So I bit the bullet and got a tune from @HassanEido. Absolutely wonderful experience, Feels great and my car has all the factory safeties. The level of transparency, communication from a tuner is something I have never seen before. So that has been great, going to start looking locally to find a dyno shop so he can get it perfect but so far the canned tune feels great.
Untitled by Sam DaJam, on Flickr