Which spoiler works best?

[zmaster]

what about the street racing spoilers like on the tuner cars.

[johnc]

what about the street racing spoilers like on the tuner cars.

 

Works for these guys...

 

EDIT: image deleted

[zmaster]

that picture didn't post

[johnc]

Probably better. It was a bad ricer joke involving wings, scoops, and wheelchairs.

[X64v]

I had thought of using a piano hinge across the hatch and the turnbuckles as well. My thought was that the hinge might just be flexible enough that it would still function despite the curve at the tail end of the hatch.

 

That's definitely an issue to research. It's clear on johnc's that it's not bent to the curve at all, some spacers are visible taking up the difference. On speedgato's, it's not clear in the pic, but it was made flat and then when screwed into the back of the hatch, it just bent to fit the curve.

 

If the piano hinge wouldn't work with the curve, johnc's method would allow it to stay straight.

[johnc]

It's clear on johnc's that it's not bent to the curve at all, some spacers are visible taking up the difference.

 

The washers were there as an inside joke. In the 2003 OTC Rylan and Aaron were running an off-the-shelf JDM rear wing on their Honda S2K and they adjusted its angle of attack via stacks of washers. Up to 25 in a stack!

 

Found a picture:

 

 

Instead of making spacers, curving the spoiler, or making filler panels, I added small stacks of washers and left them visible as a tribute to their Hillbilly engineering. On the track I filled in the gap between the hatch and the spoiler with white duct tape.

[zmaster]

thats funny, and yet ingenious

[a6t8vw]

I have a similar wing like that, i can seriously say it add's mega downforce... When im on the freeway and hit tranistions in the road or bridge gaps the car will actually bottom out in the rear. this never happened with the spoiler.

[speedgato]

Hey all, I have had some internet issues lately, so I haven't been by for a while.....

Glad my spoiler is helping some people out. When the spoiler was made, we just kept shaping, there was no real mold or pattern used. As far as the curve, it was curved a little originally, but mostly to make it a little stronger against the flow of the air. When we bolted it on it just matched the curve of the rear anyway. We put a slight bend in it starting just above the mounting holes, about equal to the slope of the hatch. So our thoughts were that with the curve of the spoiler and the angle bent in, the spoiler would have a little more rigidity. I hope that makes sense?

[240Z2NV]

Posted on a couple of semi-related threads; but, will put all relevant shots from the track today onto this thread:

 

 

 

 

 

 

 

 

 

 

Hopefully it will inspire....FWIW

[Sideways]

Pictures are dead already huh?

[240Z2NV]

That's weird!?!.... Anyone else ever have their photobucket pics just DISAPPEAR?!? I had two whole albums just vanish!

 

 

 

 

 

 

 

 

 

[zmaster]

a6t8vw That spoiler looks good on that z its perfect. do you have a model number or where can i get that one, and is it carbon fiber?

[Midnitz]

I disagree somewhat with your assumption based on physics.

 

First of all, the whale tail spoiler will have virtually 0 drag increase.

------------------------------------------------

The ENTIRE idea of creating a spoiler is to INDUCE DRAG to create downforce. any spoiler that does not induce drag is useless for downforce. This is the trade off....

This is due to it redirecting the air at the very back of the car upwards, and more effectively allowing the air going under the car to flow upwards and fill in the space behind the vehicle.

----------------------------------------------------

The spoiler induces drag by creating a high pressure surface at a chosen point on the vehicles' profile. BY inducing drag, we increase he profile of the low pressure albeit behind, below or above the car. That surface experiencing high pressure should be at the lower front of your car, and at a limited scope, to the rear of your rear wheels, just above the rear end.

 

This reduces the separated turbulent region behind the vehicle and reduces overall drag.

----------------------------------------------------

You must be talking about the pressure differential between the air moving above versus the airstream below the car....The air above usually has more velocity (higher pressure) than the air below and as they converge at the rear of the car, (at leaston our old Zs) the air above pushes the air below approx 3-4 feet to the rear of the decklid....it then moves down towards the ground and moves towards the rear bumper and up again towards the decklid, creating an unstable rear end at high speeds...at 120+ MPH, this will create lift under the rear bumper and fuel tank as the pressure builds.

 

This is why we must induce drag at this point....to "diffuse" this high pressure reversion that creeps up on our cars at 120+mph. The cost is an impact on the overall Drag Coefficient.

 

Oh and as soon as a `spoiler' allows air flow between it and the car, as in that high/rear mounted 280ZXR, it becomes a wing. Wings work better higher as they receive cleaner air, and rearward because they place more force on the vehicle with a longer lever.

---------------------------------------------------

Any surface on a vehicle that creates a pressure differential between its upper front and lower rear faces can be considered a "wing". While it is true that an elevated spoiler will receive a more laminar airflow, you will still have to fight the reversion I spoke about earlier. This is why Nascar

vehicles use the integrated style spoilers, they are more efficient.

 

 

Get a proper wing multi-element wing, as well as a smaller wing placed very close to the car down low which even MORE effectively pumps the air upwards and out from under it. Oh and while you're there, full venturi tunnels would be the go. I've just drawn up scale sketches for this on an S30, as well as designed radiator/intercooler/3 oil cooler placements and ducting.

------------------------------------------------

Actually, by manipulating the air under the car, you can make the deck lid spoiler more effective....

 

Fabbing "diffusers" for the creation of laminar air flow as it passes under the rear end is a great way to keep the air from moving too slow and creating low pressure under the fuel tank. The wheel wells are also a good candidate for air diffusers as they tend to develop high pressures.

Probably make the car slower.. hehe.

 

Dave

 

I like your enthusiam!

[m4xwellmurd3r]

I think what he ment by the whale tail having 0 increase in drag, is the overall drag coefficiency of the car as a whole, not just the wing. By redirecting the air flow over the car, i suppose you could increase downforce while decreasing OVERALL drag for the whole car. But the wing itself does function by increasing drag.

[zmaster]

personally I really don't like the whale tail spoilers,.....maybe they just have to grow on me. i guess

[mr_denner]

This one will look perfect

 

Urethane Rear Spoiler, 79-83 ZX Coupe

 

 

[JMortensen]

I disagree somewhat with your assumption based on physics.

 

First of all, the whale tail spoiler will have virtually 0 drag increase.

------------------------------------------------

The ENTIRE idea of creating a spoiler is to INDUCE DRAG to create downforce. any spoiler that does not induce drag is useless for downforce. This is the trade off....

This is due to it redirecting the air at the very back of the car upwards, and more effectively allowing the air going under the car to flow upwards and fill in the space behind the vehicle.

----------------------------------------------------

The spoiler induces drag by creating a high pressure surface at a chosen point on the vehicles' profile. BY inducing drag, we increase he profile of the low pressure albeit behind, below or above the car. That surface experiencing high pressure should be at the lower front of your car, and at a limited scope, to the rear of your rear wheels, just above the rear end.

 

This reduces the separated turbulent region behind the vehicle and reduces overall drag.

----------------------------------------------------

You must be talking about the pressure differential between the air moving above versus the airstream below the car....The air above usually has more velocity (higher pressure) than the air below and as they converge at the rear of the car, (at leaston our old Zs) the air above pushes the air below approx 3-4 feet to the rear of the decklid....it then moves down towards the ground and moves towards the rear bumper and up again towards the decklid, creating an unstable rear end at high speeds...at 120+ MPH, this will create lift under the rear bumper and fuel tank as the pressure builds.

 

This is why we must induce drag at this point....to "diffuse" this high pressure reversion that creeps up on our cars at 120+mph. The cost is an impact on the overall Drag Coefficient.

 

Oh and as soon as a `spoiler' allows air flow between it and the car, as in that high/rear mounted 280ZXR, it becomes a wing. Wings work better higher as they receive cleaner air, and rearward because they place more force on the vehicle with a longer lever.

---------------------------------------------------

Any surface on a vehicle that creates a pressure differential between its upper front and lower rear faces can be considered a "wing". While it is true that an elevated spoiler will receive a more laminar airflow, you will still have to fight the reversion I spoke about earlier. This is why Nascar

vehicles use the integrated style spoilers, they are more efficient.

 

 

Get a proper wing multi-element wing, as well as a smaller wing placed very close to the car down low which even MORE effectively pumps the air upwards and out from under it. Oh and while you're there, full venturi tunnels would be the go. I've just drawn up scale sketches for this on an S30, as well as designed radiator/intercooler/3 oil cooler placements and ducting.

------------------------------------------------

Actually, by manipulating the air under the car, you can make the deck lid spoiler more effective....

 

Fabbing "diffusers" for the creation of laminar air flow as it passes under the rear end is a great way to keep the air from moving too slow and creating low pressure under the fuel tank. The wheel wells are also a good candidate for air diffusers as they tend to develop high pressures.

Probably make the car slower.. hehe.

 

Dave

 

I like your enthusiam!

I went back 4 or 5 pages and could not find the post being quoted. It would help to actually quote the post rather than just put it in bold, especially on a thread like this which is nearing 300 posts.

 

Is the bold the new info or the original info that is being challenged? Somebody has low pressure = high velocity and high pressure = low velocity screwed around, and somebody is claiming to use physics to back themselves up but doesn't show any physics.

[dave_hl]

This is my 280's old rear spoiler. attaches with 3 screws into the hatch + adhesive along the vertical. Was on the car when i bought it, but im not a huge fan of rear spoilers on zeds, so it's now removed and for sale if anyone here is in Melbourne, Australia. (PM me)

[260DET]

This is my 280's old rear spoiler. attaches with 3 screws into the hatch + adhesive along the vertical. Was on the car when i bought it, but im not a huge fan of rear spoilers on zeds, so it's now removed and for sale if anyone here is in Melbourne, Australia. (PM me)

 

I've been looking for one of those for ages and finally gave up, ordered one a bit different from Mototsport Auto. But if you can't sell it locally and are prepared to send it to Brisbane then let me know.