rear wing for track cars

[Project-RX8]

What are you guys running for your track cars?

Mine came with a cheap unbranded wring bolted to the top of the boot and the flex is unreal. It wouldn't even surprise me if cheaper wings like the one already installed created drag slowing you down.

Airbrake wing

Branded wings that are proven to be functional?

Chassis mounted?
top of boot mounted?
inside of boot mounted?

Other?

[Dr. FrankenRex]

Paging Eddie_R32 to the wing chat.

Some are good, some are just giant air-brakes.

[casey]

Suggest you have a look here for some ideas/inspiartion (if you've not already looked ):

viewtopic.php?f=104&t=44482&start=614

I was at Castle Combe on the day in question and observed the rear wing mounts almost completely torn off the boot! Clive's now mounted the wing off the sides of the boot opening surround and replaced the boot with a lighter fibreglass one that lifts off. Clive got someone to do some aero calculations on the wing shape, size and angle.

[warpc0il]

What sort of speeds are you cornering your track car?

What other aero enhancements have you made; front splitter, flat floor?

Without a full package you're not going to make any useful increase in downforce, and it's likely that your cornering speeds aren't downforce limited anyway. The best a spoiler is going to do for you is increase hi-speed stability by deliberately inducing a small amount of drag and moving the centre-of-pressure rearwards.

[V8 Power]

These are the sort of shape that perform.
http://aprperformance.com/racing-produc ... ble-wings/

[Project-RX8]

I run a APR wing on my Honda but I can't get away spending £1000+ for a wing on the RX8, it's a joint project with my brother and he is managing the budget as my previous builds are on the extreme side.

The car has big aero up front, has a full aggressive splitter with canards that goes back as far as the oil drain on the sump, very similar to a time attack car.

Flat floor is on the cards but not yet.

The rear I have a aggressive diffuser from a Lotus and a GT Wing that is boot mounted they came with the car, never heard of the brand and looks like a budget wing, the fixings look a weak point and the boot itself has allot of flex and that's before i cut the inner skin out.

The car feels great on track.

C4273FEB-3D43-4D02-A2E2-3E8B59161676.jpeg

D9DFF78D-573C-44E8-9796-645DF3367AF0.jpeg

E07D3253-B970-4F42-90A0-5DEC4A4D7297.jpeg

Been a few mods since but this is close to how it stands.

[V8 Power]

If you know the general shape of the APR ones you may find a similar unbranded one on fleabay?
I got mine (not sure if it is APR or not) seconhand off ebay from a chap who had it on a Lotus Exige.

My previous one was awful for aero in that it had a large up lift at the back and poor general shape making it act like a parachute. You could physically feel it holding the car back at high speed.

[warpc0il]

You can make the boot lid structure stiffer by filling with builders foam - I would recommend the fire-rated stuff but it's not mandatory.
e.g. https://www.screwfix.com/p/no-nonsense- ... 50ml/83897

I was sceptical about this until I took a ride in one of the Autoglass Sierra Cosworth factory rally cars and they had foamed inside of many of the double-skinned structures, for a measurable increase in stiffness with virtually no weight penalty.

You could remove the boot lid liner, put a sheet of polythene across inside, replace the liner to hold it in place, foam all inside the bootlid, then remove the liner and polythene, leaving the whole underside of the lid foam-reinforced, and weighing less that the original lid with liner.

Actually I'd do this in two stages, foaming inside the double-skinned sections first to ensure full penetration, and then a second coat for the entire underside. Use a plant-mister to spray a light coat of water on the surfaces to ensure that the foam gets a good bond.

Just be aware that, once you've tried this, you'll be hooked on the idea and looking for all the other places you can foam inside the car

[New Duke]

Fun fact, that is actually what Mazda did to stiffen the chassis on the R3

One of the smaller, yet effective, changes from the S1 to the R3 is the foam filling of various parts of the chassis

[PeteH]

This is a good "trick" for closed (or mostly closed) sections. It wouldn't work on a single skin however. Rigid foam needs to be in double shear to have strength, but it is rubbish in tension and compression. It is also terrible at high strains, so putting it anywhere too flexible will cause it to fail.

So in something like a subframe, a double skinned boot, or (ideally) a sandwich construction between two layers of carbon fibre, it's mega.
But on a single skin it will either crack or peel off.

Also note that the problem with the boot mounted wings isn't the overall flexural stiffness of the boot, it's the local mounting stiffness. Foam will make your boot mega stiff in terms of overall torsional stiffness, but it won't make the local wing mounting points much stiffer. If you insist on boot mounting your wing, and you insist you want it stiff, your best bet (in my opinion) is to run two aluminium box sections longitudinally on the underside of your boot skin.

[warpc0il]

Okay, I've been in touch with a couple of my old contacts and it seems that I was *nearly* right before, however...

The foam used for the Ford factory rally cars was a two-part, closed-cell, hard polyurethane, originally developed for marine applications where it was applied within the hollow ribs and to the inner shells of aluminium and fibre-glass boat hulls.

The foam provided acoustic and thermal installation, significantly increased rigidity and prevented resonance stresses that could otherwise cause premature material failures.

Apparently it was injected into the box-sections and sprayed on the inside of panels. The products they used in the 90s are no longer available, because they gave off toxic gases when curing and CFC's, but similar safe(r) products are still used in marine applications today, e.g. RNLI Lifeboats where they also provide impact damage resistance and buoyancy.

Everyday is a school day

[PeteH]

And F1 seat moulds are made from it too.....

[New Duke]

I hope you remove that splitter whenever that car is on public roads and only bolt it on when you get to track. A proper flesh slicer you have there.
Hurt anyone in an accident and they'll lock you away for that.

(Number plates makes me assume your car doesn't get to tracks via a flatbed)