Does the SBR4 wing actually help?

So does the wing help at all with braking or is it so small that you cannot tell the difference between with it and without and does it even provide enough downforce to improve handling.

Look at how thin it is, I don't think I would make much big of a difference.

 

What does the thickness of the wing have to do with anything? As long as it is enough durable to withstand the pressure from the wind it's ok. Also the wind doesn't have to be that large either. Having the wing tilt upward produces more drag. The improved braking of the wing will be more noticeable the higher speed that the car is at.
You can see yourself if it's effective in braking. Just add the performance app in the apps section and do a few base test runs at 100kmh(60mph) and 200kmh(124mph) with the wing and then do the same tests but without the wing.

 

Yes it helps, but it isn't that much and IIRC because if the angle its at when down and because of the aerodynamics model it actually produces UPforce when at low speeds were it isnt deployed

 

Hit CTRL+T and see the aero debug yourself. The blue lines indicate the amount of drag created by the triangles. Hit CTRL+T again to disable it.