Black & Tan 332iT

[Bry5on]

Ah, didn't realize you did the roof rails, as well, you animal. Can it be done without removing the headliner? Big weight savings!

And my back-of-the-napkin says a George Hill carbon roof might drop the same amount in weight and not quite as much CG. Sounds lovely.

Yeah, super easy to remove, all from the top side. I think it looks more appropriate with the rack but I’ll take the weight savings any day!

Things would have to get rather serious to consider a carbon roof - that juice doesn’t quite seem worth the squeeze unless the whole car is going under for a respray and/or fenders.

[Bry5on]

New feature, because everyone needs more math in their life!

It occurred to me that since I've got suspension geometry and center of mass information, I could now add jacking force calculations to get a true representation of suspension travel (jacking is basically the geometry forcing the body upwards during lateral cornering). This led me to a cool realization! The reason BMW uses an inboard spring is probably all about minimizing jacking travel! Jacking is a force internal to the car, so it acts at the spring rate, where your suspension normally acts on the tires, a force external to the car, so it acts at the spring rate *and* motion ratio. BMW chose to have a high rear roll center for suspension dynamics, and this means that there's a lot of jacking force. To minimize the effects of jacking, you need a stiff spring rate. If BMW had put the spring over the shock with a similar ride frequency (probably the easiest thing to do honestly) then the car would rise about twice as much in the rear during cornering, totally jacking up (pun intended) your rear camber! With the spring in the location the factory chose, it turns out the math shows how little rear compression is used in corners. Most of the rear roll comes from the inner side of the rear lifting in a corner! The front is different, jacking forces are low due to the roll center being just above the ground.

So, PSA: Don't run rear coilovers unless you 1) really know what you're doing and 2) are running super stiff springs (because you have aero is the only real excuse)
Also, PSA: Don't lower the front of your car unless you 1) really know what you're doing and 2) are running super stiff springs and/or sways

In any case, my fancy suspension spreadsheet will calculate jacking forces and suspension travel for various G-loads in corners. Take a peek at the travel numbers for front vs rear and inner vs outer below:


[ATTACH]n219433[/ATTACH]

[Bry5on]

Before the day started, I took a couple minutes to add another clamp to the SS headers and wash the car. I had a resonance around 1700rpm and had a feeling that it was coming from the headers, as my original clamp was just in front of the cats and there was still some considerable unconstrained length.
I took the exact same laser cut piece from the original strap and clamped it at the headers in a different orientation (I now have a header clamp set and a section 1 clamp set). This fits super closely but works just fine.

Well, it’s smoother yet, which I love. Revving through the whole range is smoother, and I thought I’d already nailed all of the vibration before. Well, another improvement completed! I’ll have to cut down these threads later as they hang a little low.

heinzboehmer you should do this one too.

[heinzboehmer]

Nice! I'll add this to my car as well. Still have one of the laser cut parts you gave me. Were you able to get the clamps on without unbolting the exhaust?

[Bry5on]

Nice! I'll add this to my car as well. Still have one of the laser cut parts you gave me. Were you able to get the clamps on without unbolting the exhaust?

Yeah, you kinda have to snake them on a bit but I didn’t unbolt anything. All said it took about ten minutes

[jrgatfh]

Before the day started, I took a couple minutes to add another clamp to the SS headers and wash the car. I had a resonance around 1700rpm and had a feeling that it was coming from the headers, as my original clamp was just in front of the cats and there was still some considerable unconstrained length.
I took the exact same laser cut piece from the original strap and clamped it at the headers in a different orientation (I now have a header clamp set and a section 1 clamp set). This fits super closely but works just fine.

Well, it’s smoother yet, which I love. Revving through the whole range is smoother, and I thought I’d already nailed all of the vibration before. Well, another improvement completed! I’ll have to cut down these threads later as they hang a little low.

heinzboehmer you should do this one too.

how does one go about getting one of these clamps?

[Bry5on]

how does one go about getting one of these clamps?

I went with Amazon for these, they come as a pair: EVIL ENERGY 2.5 Inch Exhaust Clamp,Narrow Band Muffler Clamp Stainless Steel 2PCS https://a.co/d/dStpJ07

For the strap in between them, just make this guy here: https://cad.onshape.com/documents/93...2d931a9bf2f482

[jrgatfh]

I went with Amazon for these, they come as a pair: EVIL ENERGY 2.5 Inch Exhaust Clamp,Narrow Band Muffler Clamp Stainless Steel 2PCS https://a.co/d/dStpJ07

For the strap in between them, just make this guy here: https://cad.onshape.com/documents/93...2d931a9bf2f482

You're awesome. Thanks dude.

[Bry5on]

And one more crappy job complete! This weekend, with a helping hand from heinzboehmer, I finally tackled the black headliner conversion. I opted to go for it myself using the veteran co material and it actually came out pretty well. This was my first time doing a headliner, and I think I'd opt to have a professional do it next time.

After removing, the first step was stripping off the old felt and plastic bristle brushing the tattered foam. This makes a huge sticky mess, I did not tarp off enough of the garage floor, and I ended up trashing the tarp AND my shoes after I was done.


Then spray foam, work it down, and trim


Then pop it in, complete with all the black euro touring bits


And we're back to regular duty, the longroof party

[Bry5on]

I almost forgot, I had my inaugural e46 window regulator! And I also put in new front wheel bearings chasing what's probably just worn tires groaning. Oh well, now I've got the peace of mind at least. Thanks mrgizmo04 for the loaner tools

[Bry5on]

Did just fine with the big bike on the highway, no noticeable wind noise even though the bike is a solid foot and a half wider than the car. Trailer hitch is the way to go!

Also, in the full OCD effort to chase every little rattle noise down, I also stripped apart the HVAC controls and felted the buttons to keep them nice and quiet.

[tlow98]

That is a big bike! looks fun tho. I need to get another one of those...

[Will]

...
Also, in the full OCD effort to chase every little rattle noise down, I also stripped apart the HVAC controls and felted the buttons to keep them nice and quiet.

Wow! I didn't know the HVAC buttons rattled.

I love the build. Thanks for sharing the updates.

[Obioban]

Don't know how I missed your journal till now, but this is great. Subscribed!

[Gt4]

Get an older bike on 26’’ wheels with steeper head angle and it will be 1’ shorter, problem solved!

My 2022 SC Bronson XL also have a 50.5’’ wheelbase, at least I save 0.75’’ on my 1up hitch rack cause it’s mullet!!!