Did I overbuild my rear wing mount?

[EricP]

Two things I despise: 1) oil leaks and 2) anything that isn’t solidly “nailed” down.

So, with #2 as a driving force I went about mounting my new rear wing to the Staffs gearbox. It is nice and solid. But now, thinking about it, I realize were I to spin and swipe something (guardrail, tire wall) with the wing, it seems it would likely bend/break at the two bolts at the gearbox. Maybe that would happen regardless? What is the consideration here (aside from “don’t hit anything”)? I'm not sure if it should be "fused" to break someplace else... Pics below. A few notes:

The square aluminum tube sticking fwd and aft around the exhaust pipe will be cut flush with the black mounting tank plates, if I keep the tube. The rain light is mounted to similar square tube but it runs vertically.

[EricP]

dont know why pics turned...

[alangbaker]

If it doesn't fall apart just as you cross the finish line, then yes...

...you over-built it.

[Rick Kirchner]

i would guess that those square tubes are going to keep the wiing mounts from bending and transfer the loads to the gearbox. I'd think for the exhaust a simple half-pipe of thin stainless would do the trick and a simple L-bracket for the rain light.

I would spend the $ to get the ARB off the wing mount if possible. It just complicates gear changes and would be another thing to get damaged in the event you describe.

[Raceworks]

So if I'm reading the pictures right you're using the square tubing as a stiffiner & using short bolts to bolt it to the main wing mounting plates?

If that's the case I'd have made compression spacers with aluminum tubing and run long bolts all the way across to stiffen the mounts. For one thing it looks cleaner.

From experience any significant contact with the wing in any case is usually going to break the gearbox end case no matter what yo do. The wing mounts act as a force multiplier if you back the wing into something solid.

[Lotus7]

From experience any significant contact with the wing in any case is usually going to break the gearbox end case no matter what yo do. The wing mounts act as a force multiplier if you back the wing into something solid.

Agree completely, the cast alloy end case with its small thin mount lugs is the weak link back there, no real way to avoid it without a billet machined case and stud upgrade. Even then ...

[EricP]

So, basically, don't hit anything...

Sounds like I could lighten it up a bit (some of those bolts are through bolts with aluminum spacer tubes and others are short bolts through just one side clamping the square tube) but it ultimately doesn't matter, the gearbox link is the weak one however it gets done. I guess this car in FF trim doesn't have to worry about that...

[Purple Frog]

Actually. You want the rear cover to be the weak link. You don't want to damage a very expensive gearbox in a "minor" incident. The wing is like a rear attenuator to absorb energy as it deforms.
For that same reason you want the wing supports to bend so they use up some energy before it gets to the gearbox.
That said. I think all that "over-engineering" is a bad thing.

As usual, YMMV.

note; in the past some teams carried spare rear wing assemblies complete with the new gearbox rear cover...

[EricP]

So, maybe my question should be: do folks have problems with wobbly wings and what is the least I can do and still have a solid mount? That is kinda answered above but I’m curious about experiences....

[S Lathrop]

Here is a wing mount (one side) that is designed to be a crush structure as well as a mount for the rear sway bar and the rear wing. It also has a receiver for a quick lift jack. There are 5 spacers between the 2 side plates.

It is designed for the Staffs transmission. The wing mounts on the top in the 2 rear most holes. There is a separate plate that mounts to this mount and then the wing mounts to that plate. The plate that the wing bolts to allows for fine adjustment of the attack angle of the wing and the plates are designed to give the desired wing height relative to the diffuser.

[EricP]

Here is a wing mount (one side) that is designed to be a crush structure as well as a mount for the rear sway bar and the rear wing. It also has a receiver for a quick lift jack. There are 5 spacers between the 2 side plates.

It is designed for the Staffs transmission. The wing mounts on the top in the 2 rear most holes. There is a separate plate that mounts to this mount and then the wing mounts to that plate. The plate that the wing bolts to allows for fine adjustment of the attack angle of the wing and the plates are designed to give the desired wing height relative to the diffuser.

That is cool.

My Staffs box only have two wing plate mount holes. ???

[S Lathrop]

That is cool.

My Staffs box only have two wing plate mount holes. ???

The drawing is for the LD200. But the idea is the same regardless of the box.

[EricP]

The drawing is for the LD200. But the idea is the same regardless of the box.

Got it...

[EricP]

Although eventually I’d like to do what Steve shows above, this is better than what I had. Not rock stiff but solid enough and simpler. Plus, the routing of the rain light wires is cleaner.

[phantomjock]

Here is a wing mount (one side) that is designed to be a crush structure as well as a mount for the rear sway bar and the rear wing. It also has a receiver for a quick lift jack. There are 5 spacers between the 2 side plates.

It is designed for the Staffs transmission. The wing mounts on the top in the 2 rear most holes. There is a separate plate that mounts to this mount and then the wing mounts to that plate. The plate that the wing bolts to allows for fine adjustment of the attack angle of the wing and the plates are designed to give the desired wing height relative to the diffuser.

Nice. Any chance there is a download-able stl/dxf/3dm/etc available to run over to the plasma cutter?
I'm guessing maybe 3/8" Aluminum?

Cheers - Jim

[S Lathrop]

I did not do this design myself and as such I am not comfortable passing the model on. It is not that difficult to do.
The part is actually 1/2 inch. And I would recommend water net cutting. Cutting methods that burn their way through materials are not good on aluminum.

[Steve Demeter]

Eric,

If you have room in the max extension allowable of the exhaust you might consider making the pipe a bit longer so that it does not end right below your wing and right next to your mount. Assuming that you do not have it finely tuned at the present length.

[EricP]

[QUOTE=....Assuming that you do not have it finely tuned at the present length.[/QUOTE]

That’s funny! How about adding a phart can?

[Rick Kirchner]

20% improvement if Honda powered..... I read it on the Civic forums!