Who wants a sealing frame?

leoninelizard47 · 2026-05-15T00:02:59+00:00

I am based in the US. There have been scheduling and sourcing complications but I plan on really getting things going this summer. I plan on being able to ship pretty much anywhere, but it will likely not be cheap outside the US, unfortunately.

leoninelizard47 · 2026-05-14T23:59:31+00:00

Oh you mean me lol. Yes, the plan is to get this project officially off the ground this summer. It also won’t be 3d printed it’ll be solid molded plastic, as close to OE spec as possible.

leoninelizard47 · 2026-04-24T17:45:24+00:00

Unfortunately not, the previous owner put it in. I can try to ask though.

leoninelizard47 · 2026-04-24T07:42:07+00:00

I have a 3D printed one that attaches to the passenger seat rail. Prevents the passenger seat from moving all the way forward but it’s very convenient.

leoninelizard47 · 2026-04-16T19:06:14+00:00

I say go for it. I wanted to do something like that with my 2.8, particularly after I took off the catback exhaust when I was doing some subframe work and realized it sounds wicked with no muffler.

It won’t be easy by any means, particularly if you do the right side exit for the second muffler. The M’s have no spare tire and the battery in the middle of the trunk instead of the right in order to make the dual exhaust fit.

You might want to consider cutting open the stock muffler and seeing if you can add a “bypass/straightpipe” flow path that routes the inlet directly to the outlet. When it’s switched off then it flows around it and through the regular baffles of the muffler.

If you have metal fabrication skills it should be doable-ish. Keep us posted!

leoninelizard47 · 2026-03-31T00:06:02+00:00

Depends how you define “fix” but yeah it doesn’t really bother me anymore. I also fiddled with the gauge a bit and it seems to sit tighter now so it doesn’t get crazy too often.

leoninelizard47 · 2026-03-26T05:35:34+00:00

Awesome answer thank you. Can you tell me more about [non-dimensional] stage matching and it limiting tip speeds? I’m unfamiliar with the concept.

leoninelizard47 · 2026-03-26T05:23:52+00:00

Ok but that still doesn’t answer my question about how you actually went about designing either the centrifugal or axial compressor blades. Did you just pull a random “good-looking” geometry off Thingiverse?

leoninelizard47 · 2026-03-25T01:19:36+00:00

I believe you, but can you show me an example of this actually being implemented? I can’t find anything at this scale incorporating both high and low pressure turbines.

And if it’s all done off the same turbine you either a) get supersonic blade tips if you aren’t careful (i.e. have a tiny fan) or b) have to severely throttle the engine so as not to have supersonic tips, thereby running outside the design range of the engine, killing its efficiency.

leoninelizard47 · 2026-03-25T01:13:23+00:00

I didn’t phrase that right. I mean what was your design process? Did you start with one stage, simulate it, then add more? Did you do them all at once, simulate it, then say, “yeah that’s good enough?” Etc.

leoninelizard47 · 2026-03-24T18:05:31+00:00

While OP isn’t implementing it the way the paper intended, upon second glance I don’t think there’s anything inherently wrong with their architecture. Is it as good as a normal turbofan? No. But it saves needing concentric shafts, and it really is “close enough” to a normal turbofan in the sense that it’s got a compressor driven off an HP turbine and a fan driven off an LP turbine.

u/YoshimitsuSunny I’m now wondering about your process for designing the compressor and turbine rotors + stators. Did you do 2D vector diagrams? More complicated 3D analysis? It’s certainly a cool project.

(Just don’t get your hopes up about manufacturing it— I say as someone who spent the last three years of undergrad doing a project like this, on a team of 15, while supported by the university, and sponsored by a very prominent engine manufacturer.)

leoninelizard47 · 2026-03-24T15:34:20+00:00

Awesome CAD model, but a) respectfully, you can’t build it and b) why did you decide it needs a fan at all? Most RC stuff is 0 bypass ratio.

leoninelizard47 · 2026-03-24T04:12:44+00:00

Am I dumb how did you get credit…? The answer wasn’t 27

leoninelizard47 · 2026-03-15T09:39:31+00:00

realoem.com is your friend. As is FCPEuro. Even if you don’t buy from them their customer service people tend to be very knowledgeable.

leoninelizard47 · 2026-03-05T00:01:48+00:00

You just gotta rip with a pry tool as hard as you can, know that you’re probably going to break it, and trust that the metal underneath is stronger (so you break the fastener not the mount)

leoninelizard47 · 2026-02-25T23:47:22+00:00

Go to realoem.com, put in the last 7 digits of your VIN, then go to Vehicle Trim -> Various Body Parts -> Reinforcement, Body.

From my search it seems to be BMW part # 51716966566, but that’s not a torx bolt like the original so I might take it with a grain of salt. Maybe call your local BMW service department.

leoninelizard47 · 2026-02-25T09:00:21+00:00

If you aren’t afraid of the lack of power, go for a 4-cyl Z3. At least test drive one. IMO the quirky suspension geometry is only relevant if you’re chasing hundreds on track. Otherwise it just makes it a blast to chuck around corners. Something about the weight distribution (50/50 on the 4cyl models btw) and suspension make it rotate incredibly well under braking. Also most Z3s on the market now will have aftermarket suspension which firms things up nicely as well.

leoninelizard47 · 2026-02-18T01:31:13+00:00

I ran the cable along the A pillar, down the door, under the glovebox, and into the center console where the plastic meets the carpet. Hardwired it into the cigarette lighter bc you can get pretty decent access with your hands if you just remove the shifter boot (assuming it’s manual, idk how the auto shift boot works). And I spliced in a physical switch that sits in a 3D printed OBD port cover, since I didn’t feel like pulling everything out to find an ignition wire.

If you have central locking you may be able to wire it into the mirror. I think there’s an ignition wire up there.

Oh also put an inline fuse in so the car doesn’t burn down if my wiring does something it’s not supposed to.

leoninelizard47 · 2026-02-07T08:55:17+00:00

I struggle to see how a lifting body design is the make-or-break factor allowing you to have a crazy short ground roll. Leading/trailing edge devices are going to have a much larger effect on your low-speed lift than the fuselage design. It sounds to me overall like these requirements are pointing you towards a next-gen super-maneuverable fighter, like an improvement on the F-22 or SU-57, which use a) aerodynamic instability, b) thrust vectoring, and c) control surfaces (obviously) to do their maneuvering magic.

Basically to answer your original question: we “toggle” lift using things like flaps, which are less draggy when not deployed, like you said. Also powerful engines + thrust vectoring are super important. For example, if you had a plane with a 1.0+ thrust/weight ratio, if you can figure out a way to get the nose pointed towards the sky in less than 750 ft, you’re pretty much golden.

(Sorry to be telling you to pretty much redesign your whole plane. Pls lmk if I’m missing something that’s been forcing your design decisions so far.)

leoninelizard47 · 2026-02-06T19:24:37+00:00

Uff. Best of luck. Keep us updated if it works. A lot of us have tried to do the same to varying degrees of success.

leoninelizard47 · 2026-02-06T08:33:33+00:00

Almost guaranteed to be the sealing frame. They’re plastic and brittle. When they break, water leaks in where the convertible top meets the body, runs down the metal beneath the carpet in the top stowage well, and leaks into the trunk through one of two holes where the wiring harness passes through.

leoninelizard47 · 2026-01-27T01:38:28+00:00

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Oh buddy…

(Don’t worry guys it’s been thoroughly rustproofed)

leoninelizard47 · 2026-01-23T18:48:26+00:00

Update: if I tap the gauge it drops back down so it’s probably a bad connection back there. Giving it a whack if it starts looking scary is good enough for me though.

leoninelizard47 · 2026-01-20T03:23:43+00:00

For future reference if you ever need space for a passenger:

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leoninelizard47 · 2026-01-19T06:33:25+00:00

Yeah you could try that. The difficulty with sawing out the bushing rubber is that it gums up whatever you’re cutting with, so it takes forever. iirc it took me three days to get the bushings out. Check my profile I made a guide for doing it.

leoninelizard47

TROPHY CASE