heinzboehmer's 2002 Topaz 6MT Coupe

[heinzboehmer]

Printed a TPU test piece in the same dimensions as the -16AN hose, and it fits perfect. It's pretty much exactly the same as what's on there now.

Unfortunately, I just cannot find a -16AN hose that has the internal Viton liner. The Raceflux stuff above only goes up to -12AN, unfortunately. There's lots of -16AN PTFE lined hose available, which is likely better, but all of it is white...

So, I caved and bought the BMW stuff. Don't want to delay getting the car back on the road just cause I'm being stubborn.

[heinzboehmer]

Hate to say but 50 is not much when you consider the downtime, I'd buy the stock hose unless you can quickly find a source, sometimes these type of things just don't exist in the open market, unless you source by dimension and not care much about the very same spec, and just change it every now and then I guess.

Yeeeah, I'm slowly starting to realize this. There are no good consumer sources for the hose, unfortunately.

The only lead I have is that -16AN hose is almost the exact same dimensions. There seem to be some companies that produce what I want, albeit with a couple extra layers that I would have to remove. e.g.:



I have yet to find someone that sells an FKM/ECO/whatever hose in -16AN size, though. I'll keep looking, but it's totally possible that I'll need to give in and just buy the BMW stuff.

[maupineda]

Hate to say but 50 is not much when you consider the downtime, I'd buy the stock hose unless you can quickly find a source, sometimes these type of things just don't exist in the open market, unless you source by dimension and not care much about the very same spec, and just change it every now and then I guess.

[Obioban]

If you have to buy a longer section, I’ll buy some off you

[heinzboehmer]

So, car went into limp mode twice on me today (reset codes in between). This was the only code in the DME when I got back home:



Took the intake side of the engine apart to see if there were any obvious issues.

Hmm, no wonder:



I guess that's not really all that surprising for a 23 year old hose that was held on with a shitty hose worm type hose clamp.

The rest of the hoses in the idle air path aren't looking that great, so decided to replace all of them. However, turns out those two small hoses on the tube that goes to the idle air rail are $50 EACH. I feel dumb paying that much for 50mm of hose, so time to look for an alternative.

Stock hose has "FPM/ECO" printed on it and measures in at ~20mm ID/~30mm OD:



The FPM (Viton) part is easy, but the combination of both FPM and ECO seems a bit harder to find in those dimensions. I'm sure I can find a distributor, but have to keep looking.

Also, I just have to say that it felt really nice to only have to remove the left brace and still have all the necessary access to the intake side of the engine :

[heinzboehmer]

Just fixed one of the more annoying rattles I've had in this car.

When going over small potholes or driving on rougher roads, I could hear a faint metallic clinking sort of noise. It sounded like there was a washer rattling around inside the rear right C pillar cover.

This had been going on for a while, but the rattle was quiet and infrequent enough that I mostly just ignored it. Plus, I knew the plastic screw bracket on that C pillar cover was on its last legs, so I figured it had finally broken and the screw was rattling around.

However, the C pillar covers have been off since the deep clean (because that bracket did indeed fail) and the rattle was still there! Not only that, but it was significantly louder and way more frequent than before.

Banging on stuff with the car parked in the garage never caused the rattle, so I was stumped.

BUT, I had a breakthrough earlier today. Was driving on a slower street and realized that the rattle sounded like it was coming from closer than the C pillars. Pulled over and realized that banging on the dashboard made it happen pretty reliably. A repro! Finally!

Drove back home, parked the car, banged on the dashboard and absolutely no rattle. What!?

Started thinking about what variables had changed and slowly zeroed in on the only one: the position of the handbrake lever.

And wouldn't you know. Handbrake down, rattle. Handbrake up, no rattle.

Took the center console apart, kept banging on stuff and realized that the rattle was coming from the locating tab for the center console bracket:



Turns out that when the handbrake is pulled up, its bracket flexes juust enough to butt up against that tab and stop the rattle. How annoying.

Copious amounts of tesa tape later and the rattle is gone!




Too long of a post and way too much effort for a stupid rattle, but man, it was driving me absolutely nuts. I'm so glad to have resolved this

Has been a pretty good week for the M3

[heinzboehmer]

parked the car and my front brakes immediately began to smoke (I'm guessing the dust boots are once again toast, yay), so I had to jump back in the car and drive it around the paddock for a bit to cool them down.

Well, turns out I was wrong.

Swapped back to street pads today and I couldn't find a single crack on any of the dust boots. They're all still in perfect shape:



Honestly kinda blown away that the dust boots survived that.

Also, I have no idea what did catch on fire, but I can tell you that smoke was pouring out of both front wheels before I hopped back in to do the cooldown lap of the paddock. Maybe it was from tire rubber stuck to the inside of the wheels?

Anyway, I'm super happy that I don't have to swap the dust boots out for the millionth time.

Nice work!! The car lives to fight another day

This thing is tougher than I thought!

[Arclitgold]

Nice work!! The car lives to fight another day

[heinzboehmer]

Enough of driving myself crazy over some dust and onto more interesting topics:

Finally sat down to analyze the thermocouple data. Quick notes on the test setup:

• Logged as many scenarios as I could, so data would include multiple driving styles (highway, around town, on track).
• Track day was at Buttonwillow 13CW.
• Ambient temps were between 20-28 C.
• No clouds, sun was out all day.
• Car was purposefully not parked in the shade to maximize heatsoak.

Alright, let's jump straight to the analysis. Unfortunately, there is way too much data for datazap to handle, so you guys only get non-interactive images this time. Here's everything I captured throughout the day concatenated into one big chart (vertical discontinuities are from when the ignition was off, x axis is time elapsed):



Some key takeways after looking through the data:

• Any airflow in the engine bay quickly drops temps for all thermocouple locations (more on that in a bit).
• Temps behind the firewall consistently trail engine bay temps by ~20 C, which means the thermal insulation properties of the 3D printed parts work!
• At steady state, the engine bay thermocouples settle at ~60 C and the ones behind the firewall settle at ~40 C.
• Convection seems to play a bigger role in the temps of these parts vs radiation.
• Max values for each location follow:
  • Firewall Plug: 84.1 C
  • Passenger Brace Underside: 86.8 C
  • Windshield Mount Front: 65.5 C
  • Windshield Mount Rear: 63.9 C

During one of the track sessions, I decided to completely skip any cooldown and park the car as fast as possible in the paddock to maximize heatsoak in the engine bay. This was, of course, a dumb idea. I parked the car and my front brakes immediately began to smoke (I'm guessing the dust boots are once again toast, yay), so I had to jump back in the car and drive it around the paddock for a bit to cool them down.

Regardless of the impromptu cooldown, I still managed to get the highest engine bay temps during this part of the experiment. Here's a zoomed in and annotated view on just that part of the data:



The "Engine On" and "Drive Through Paddock" sections showcase my previous airflow comment perfectly. As soon as you start moving any air in the engine bay (from fans or from driving around), the temps drop rapidly. Pretty cool to see.

Anyway, key takeaway from this testing is that the windshield mount is not getting nearly hot enough for 7075 temp degradation to be a concern. Very happy to see that .

[heinzboehmer]

Many, many hours later, the interior is clean again.

I started by just vacuuming things out, but I just kept finding dust/sand everywhere. Started taking things apart and quickly arrived at this:




Ended up basically taking the entire interior apart. Was crazy to see just how far into things the dust made it.

For instance, found sand dunes in the trim for the rearview mirror:



I guess that's not too crazy, since it's not exactly a sealed part. But look at this:



It got inside the rearview mirror. How!?

Unfortunately, I broke the ribbon cable for the homelink module when taking it apart, so had to break out an emergency repair:



I smeared a bunch of glue on top of the solder butt joint to try and make it reliable, but I can't imagine this fix will last long. Oh well. At least the daughterboard with the ribbon and buttons should be an easy piece to scavenge out of a junkyard mirror. Added to the list.

I also took anything with buttons apart and cleaned out everything on the inside. This is what all of the buttons on the car looked like and why everything felt crunchy when pressed:



Funnily enough, now some of the buttons are so clean that they squeak when pressed. Bought some of the Krytox that comes in a bottle with a syringe cap, so will go around the car with it to make everything nice again.

Most of the interior is back together, but I still need to reglue some of the fabric on the A pillar fastener covers that came off and fix a broken tab on one of my c pillars. Will post some pics of that later.

[heinzboehmer]

Glad you’re ok!

Im nerdily watching the progress on the filter housing! Nice work

Thanks! All the damn cleaning put a dent in the progress with that, but have a new revision almost ready to print. Battling some install issues, but I'm sure I can make it work. Should be able to get to that soon.

The worst part is not knowing how bad the damage is until you get into the paddock.

Let me know if you want a carbon plate!

Want to run the carbon plate I am not using?

I would love to get one, one day, but the steel one is much better and stronger for impacts and wont shatter.

Appreciate the offers on the carbon plates, but I think I'm gonna stick with the metal one, for the same reasons 0-60motorsports pointed out. I can't promise that I won't do this again and shattering a carbon one sounds pretty scary.

And now for the moment of shame:

https://www.youtube.com/watch?v=DVXukfuyi3A

As is obvious, this was 100% a driver skill issue. The car is clearly unsettled and struggling for grip from a few corners back (note how twitchy my hands are in the long sweeper). I should have slowed down more in the braking zone for Phil Hill, made sure the car was settled and then attempted the corner. Going in too hot + weight in the wrong places + a bit of understeer at the crest was more than enough to send me flying.

Post-impact, I think my steering inputs were good, but I should have reacted a bit quicker with the throttle. Had I done that, I might have neen able to carry the drift and avoid the mouthful of dust. Wouldn't have helped with the damage to the shear plate, but at least everything wouldn't have gotten so damn dusty.

Also, you can see me give up on trying to save it and just go WOT after the second countersteer. It became clear that I was gonna go off sideways one way or another and that was my attempt at scrubbing speed NOW. There was some very dry looking sand right next to the track and some wetter looking stuff a bit further out. I was afraid of hitting the mud sideways and rolling, so I opted to spin out instead. Not sure if that was the correct choice, but hey, that's the decision my brain made in the moment.

[0-60motorsports]

Want to run the carbon plate I am not using?

I would love to get one, one day, but the steel one is much better and stronger for impacts and wont shatter.

[Arclitgold]

Glad you’re ok!

Im nerdily watching the progress on the filter housing! Nice work

[maupineda]

T


But now, the bad news. During one of the afternoon sessions, I came in a bit too hot into Phil Hill and completely missed the turn. Landed with the left tires in the dirt and the right on the pavement, which means I hit the curb at the bottom of the hill pretty hard against the undercarriage. I then drove back onto the pavement for a second and lost it again, spinning out into the dirt on the left side of the track.

Fortunately, the aluminum shear plate took ALL of the damage. I still can't believe I got as lucky as I did. Absolutely nothing else was damaged (including the brake and fuel lines right behind where I hit the car on the curb) and the car stayed right side up..

Want to run the carbon plate I am not using?

[bigjae46]

But now, the bad news. During one of the afternoon sessions, I came in a bit too hot into Phil Hill and completely missed the turn. Landed with the left tires in the dirt and the right on the pavement, which means I hit the curb at the bottom of the hill pretty hard against the undercarriage. I then drove back onto the pavement for a second and lost it again, spinning out into the dirt on the left side of the track.

Fortunately, the aluminum shear plate took ALL of the damage. I still can't believe I got as lucky as I did. Absolutely nothing else was damaged (including the brake and fuel lines right behind where I hit the car on the curb) and the car stayed right side up.

The worst part is not knowing how bad the damage is until you get into the paddock.

Let me know if you want a carbon plate!