Well I want to make a custom spoiler for my 240Z and so I drew a few sketched. Please provide you opinion as to which spoiler you like best or is the car better off without a spoiler or suggest a new design.

The spoiler will be made of fiber glass. I’ll first make a consumable mold out of Styrofoam and then glass over it.

NO SPOILER

SPOILER 1

SPOILER 2

SPOILER 3

SPOILER 4

SPOILER 5

SPOILER 6

SPOILER 7

SPOILER 8

SPOILER 9

No spoiler at all

The last wing with the uprights leaned back like that will have additional leverage over a wing on vertical uprights and will produce more downforce. The spoiler #6 with the highest angle of attack would probably have the most downforce of the spoilers.

If you search you might find the C&D article from the 70's that compared drag and downforce for various spoilers. Some of the less aggressive angles, like maybe #5, should actually decrease drag so you'd eliminate some of the lift at the rear and gain gas mileage.

You might check the aero forum over at hybridz.org. I think they'll be more receptive in general to the idea of putting wings or spoilers on the Z than this board will be, and they've actually done a wind tunnel test of most of the common aero parts that you can buy for the Z too.

I think your splitter and diffuser are not likely to function very effectively on a road car. You need them to be pretty close to the ground to really work, and then you need super stiff springs to keep the car level to keep them working consistently.

With those as the choices I'd also have to say no spoiler at all. I'm actually trying to envision you renderings on an S30. It's hard to tell on that rendition because, at least to me, it's not really indicative of an S30. The body lines aren't right. Looks more like a modern retro Z.

If any - No 5 is my choice

What are you using to make a decision - looks or functionality?

Personally, I'm more concerned about the looks of the front. The front spoiler with the headlight looks like a shark about to bite into a surfboard. The lines are too awkward from the dam over the hood. And I definately would stay away from the cell phone tower inspired spoilers in the last two pics. So, #5 or none at all.

Also bear in mind, I occasionally drive a Volvo too.........

IF I were interested in a rear spoiler for my car, I think that rather than try to reinvent the wheel, I'd be looking for something with a proven aerodynamic track record, like the rear BRE unit.

IF I were interested in a rear spoiler for my car, I think that rather than try to reinvent the wheel, I'd be looking for something with a proven aerodynamic track record, like the rear BRE unit.

BINGO... Probably the nicest looking one ive seen out there too.

You can also add a second air dam under the car in front of the rear axle.

Edited October 24, 200915 yr by TomoHawk

You can also add a second air dam under the car in front of the wheels.

Yes, you could but that would be a front air dam and this thread/poll/whatever is about a rear spoiler.

I vote with the "None of the Above" group. The BRE style has looks and function and can be shipped to your door in a nice box - no need to fabricate unless you have a need for personal expression. In which case, our votes really don't matter.

Dennis