Sam-Son

Congrats on the 996. Nice E34! I used to have an S52 swapped E34 track car. Also had an E39 touring recently

c didy

very nice roof mount.

circuit.heart

Ok, we are live! Still improving with each iteration.



I went far too aggressive trying to lower the landing pad, so both fronts and rears are touching the rain rail in these pics - easy to fix. I'm trying a more universal approach to the gasket, using closed-cell EPDM foam to conform to the various curves on the roof without needing custom machining for each of 4 landing pads. I guess that automatically makes it cheaper-feeling than the Porsche RTS, but I believe I can keep the overall fitment tight still. And it's definitely possible to get the front bar lower than the RTS. Nice and sleek looking!



The front towers are able to level the aero bar to a nice angle with no other tweaks, so I'm not gonna tweak its angle in a bid to keep the front landing pad as low as possible. On the other hand, the rear towers are leaned back 10deg too far, and about 1" too low to level a roof box. Rectifying those two, along with a few more tweaks, gives me the next revision of the parts:



Printing with more infill and more care this time so we can do a functional test - can't wait!

circuit.heart

Before diving into roof rack stuff: I finally got the car re-aligned the other day, and it was transformative.

(Degrees)
F Camber: -1.2, maxed out factory struts and tower slots
F Caster: 8
F toe: +0.02
R Camber: -1.0
R toe: +0.08

Fuel economy gained ~1mpg, the steering no longer "cams over" during tight parking lot turns, and most importantly the front end doesn't wash out anymore on trail braking - I'm actually getting rear rotation which can then be planted with the throttle. Nice! Guess the "find a parking lot to hoon" idea can be put on hold as it finally drives intuitively enough that I think I can sort myself out in an emergency. That solves one of my biggest worries with this platform!

Now on to roof rack stuff.



Got the new prints installed, adjusted the Yakima bars and went for a drive. The new landing pads clear the "flap" in the rain rail, torque down nicely (function of the geometry + the gasket material being used) and held to 90mph in this initial test without any weird noises or vibrations. For further functional testing, I'm going to want to CNC mill the landing pads because I can't afford to drop a whole box and rack assembly onto some innocent motorist should be a 3D print fail at 100+mph.



The front pads are about as low as they can be made - I've used a low-profile mounting screw, only 3.2mm of meat between the screw head and the flap, and lowered the Yakima tower such that it's practically scraping the screw head. There's comparatively way more design freedom in rear pads, so I just tried to make the cross-section (aka frontal area) thinner to reduce drag. A teardrop profile was considered but that would end up making these landing pads too long and not match the fronts aesthetically.



Left/right pieces are symmetrical to avoid potentially stocking 4x parts instead of 2x, but because Yakima racks are more utilitarian anyways, I think it complements the looks rather than detracting. Let me know if you disagree, as I'm not just trying to satisfy myself with this development. I personally think this looks way better than the RTS, being slightly lower and significantly wider (ain't that just universal? ) than the Porsche rack.





I cannot wait to throw the box on top and be able to lug stuff on road trips!

2002C2

TBH I didn’t read every detail but the process is cool. What is the print material you are using? Do you trust it to be strong enough and withstand UV radiation?

merlot

Do you plan to make the custom landing pads available to purchase? I'm a Yakima user as well. I have a set of landing pads I used on my old 2008 STI, and they will work on the 996, but as you stated, the rear ones are too low. Hence my interest.

hatchetf15

OP - The car looks happy now. With the better suspension set up, you’ll really enjoy driving. Is the Tip downshift performance to your liking as you corner out? Love the rack mount mod work.

circuit.heart

These prints are ASA, but you'd be insane to rely on this to lug something like a roof top tent. I only use 3D prints for non-load-bearing stuff, otherwise it's only good for fitment checks (fantastic for that). I've shot an email to a prototype shop in China I'm familiar with, hopefully they can make me something Delrin or aluminum at a reasonable cost and then I can do real mechanical testing. Might just have to buy a copy of ISO 11154, but from what I can tell (based off other companies making roof transport systems and the like):

• Driving over 200km/h / 125mph with a 20kg/45lbs load
• Driving on the infamous Belgium block paved road with the rack loaded with 20kg/45lbs (I might have to settle for downtown San Jose)
• Emergency braking tests from 80kph/50mph - loaded with 20kg/45lbs
• Speed tests at 130km/h 180km/h 80mph/110mph
• 10 minute pulling force assessment with 645N applied approx 65kg/145lbs to the loaded rack.

I found some companies offering to test roof racks for you; they claim to test for 8G crashes with a loaded rack so I think that means

• 8 * 45 = 360lbs pulling or pushing force to the loaded rack

There's also the obvious static load test:

• At minimum, handle 165lbs of static load
• Realistically, should be able to handle normal roof top tent loads (150lbs of tent + 350lbs of humans)

If it handles all of those things I'm pretty sure I have to worry about the rack itself as the weakest link and not the feet that I'm going to try to overbuild on purpose.

If things actually test out well, yes! I don't really enjoy making things just for myself, I would've just lived with a Porsche RTS if I didn't think we could make and share a better product.

Car's much happier now, probably more so once I give it clean injectors and new spark plugs. I never even thought about letting the Tip kickdown during actual driving, that seems scary. I ask it for a downshift before entering the corner and rev-match the downshift myself. Would be slick if I can make a little module that takes the Tip switch input and modifies the E-gas signal to auto rev-match, but that's something I haven't fully understood yet

theprf

If you have the Mercedes Tip it will learn from your driving style and do really neat things. Like, if you brake hard it will assume you are going into a corner so it will predownshift and hold that gear while the wheel steering is not straight.
It quickly forgets that strategy if you start driving smoothly though.

circuit.heart

I noticed that, but the trans just downshifts without blipping the throttle, and the car winds up wanting to shift lock in the middle of trail braking. That's hairy IMO... erring on the side of caution, I just leave it in M and drive it like a "dumb" manual when needed.

theprf

That's what I did when I ran mine on the track. Not relevant to your car, the Tip does a no-lift-shift to keep the turbos spooled; I have datalogs to prove it.
I ended up manual swapping the car.

circuit.heart

Development continues, I placed an order with a prototyping shop to CNC mill me some aluminum versions of these feet. I plan to run the gamut of load tests on the aluminum feet first as they better pass everything, so I can learn what kind of test setup (as well as car protection) is needed to check that everything's working. If the aluminum feet work, then it's time to see if there's enough demand to actually make a batch of these in (most likely) cast nylon.

This was ill-advised but I really needed to see how a roof box looks on the rack, 3D printed feet be damned.



The bar-to-roof clearance looks about right; plenty of space for these Inno hook mounts, and if you use a ski holder the raised rear bar already gives plenty of clearance for bindings.



For obvious reasons this was driven around very gingerly... but it still did 45-50mph on city streets with no signs of fatigue or loosening up.



A few more views.




The rear bar can probably be lowered another 2-3mm. Most people run a little ride height rake on their cars, so I should account for that when trying to keep the box level for aero drag purposes.



I think it looks pretty good. Can't wait for those Titan7's to come in, I have a few ideas for further tweaks to the C2 once it's on the right set of wheels.

merlot

​​​​​​​I'll be first in line!

circuit.heart

While waiting for the machined rack pads, I've made a rough scan of the 996 interior to start putting pen to paper. New software too - Autodesk Fusion and Solidworks can't handle this point cloud on my mid-grade PC, so I bit the bullet on a Rhino license. (I know Blender is powerful too, but somehow I can't wrap my brain around its UI whereas Rhino has been intuitive for me for 20 years.)



Now let's discuss: I think most of us agree the 996 interior isn't particularly well styled. There are lines everywhere, design elements don't match or complement each other, and the (front/upper) center console especially is both ugly AND takes up legroom. Brainstorming around that console is a head-scratcher:

• For modernization, we need room for a double-DIN (PCCM+ or other big-screen Android headunit) and the HVAC controls, so 2-3 DINs worth of space, depending.
• If we must have only 2 DINs (dashboard space only), then the only way is to reverse-engineer the HVAC controls and put them into a smaller package a la @Kaelstart
  • Smaller HVAC controls would be neat though, you could fit them in a 993-like lower console and that would complement the tapered tip of the 996 lower console.
• If we keep 3 DINs, the HVAC controls need to be as out of the knee's way as possible for ergonomics.
• The visual weight of the center console assembly is important - the lighter looking the better, and separating the console from the dashboard will help.

For easiest user adoption, it's better to make fewer pieces, each being usable independently from each other. That means finding a way to use the stock HVAC controls, sooo figuring out how to make them shrink away while actually keeping them within reach (no glovebox tricks). That's not a problem I expect to solve immediately, so for now I've put my best brainstorm idea into the renders below, basically flying buttresses that tuck the HVAC controls further down under the dashboard.

One piece I'm firm on making, whether other people like it or not, is the horseshoe. I hate the factory horseshoe. It's such a missed opportunity that Porsche could've taken, but instead it's like they shrink-wrapped plastic trim around the air vents, radio and buttons and called it a day. IMO, it didn't take much effort to do better, and this is only the first draft.



Front 3/4 view: the horseshoe can, and should, mirror the theme from the instrument cluster hood. That means a slight overhang, a small radius on a sharp upper edge, and if you have a leather cluster hood, the horseshoe should also get a leather seam right on the edge. I'm thinking that the flying buttresses should extend from under the dashboard all the way clipping into the rear console. Long, unbroken lines help make things look slimmer.



Front view: the cluster hood curves convex just a bit, so to complement it, I've made the horseshoe curve concave just a bit. That's not possible to do at the seam of course, so the concave feature is within the face of the horseshoe itself. You can also see my idea for the center console here - make it as narrow and as light-looking as possible. In this outline the buttresses are about the width of a single-DIN, saving a few inches over the original center console which was the width of the horseshoe.



Top(ish) view: the horseshoe now has a plateau to an overhanging cliff, just like the cluster hood. I want to adjust my cut lines in the horseshoe to clean up near the upper buttons. You can also see my idea for the center console kinda works - because the buttresses are set deeper underneath the dashboard, it provides some separation between the "dashboard" and the "center console" as two entities. Not as much as a GT3 console delete of course, but, if we wanted to be as light and airy as possible I'd literally leave the buttresses like this and install a GT3 console delete underneath. Otherwise, the space under the HVAC controls would be great utilized as a phone mount/wireless charger or even cupholders I'll have to disassemble my center console to know how deep the HVAC controls can actually be mounted, which then informs how much slimmer we can make the buttresses and how feasible it'd be to have real cupholders in that area.

That's it for now, please hit me with all your constructive criticism and feedback! I'm gonna print a horseshoe this weekend just to see how good my reverse engineering is, but that'll be a good opportunity to test the aesthetics in reality too.

freddworks

Interesting project.

The only part I don't really like about the interior is like you have addressed, the the center console and dash doesn't really seem to follow each other.
Looking forward to updates on this!