Rear Spoiler

[drunkmonk2]

I was wondering where you guys get the rear spoilers for the cars. Im looking at doing mostly for improved gas mileage. Is this something that actually improves gas mileage.

[Charlie1717]

I was wondering where you guys get the rear spoilers for the cars. Im looking at doing mostly for improved gas mileage. Is this something that actually improves gas mileage.

Junk Yards, on here in the for sale section, ebay, craigslist, Ernst/Junspeed (members here).

I don't think there is a noticeable difference in MPG's... I don't think it really improves efficiency in that regard.

[rmoltis]

most lip spoilers that say sit on top of a trunk or at the top of the roofline are designed to help minimize low pressure zones,
by creating high pressure zones at the rear of the car.
this help keep the laminar flow of air over the vehicle close to the body.
that way once it reaches the rear of the vehicle it can diffuse and come back together easier.



you break the wind over the front of your car.
the high pressure zones cause resistance/drag when moving forward.
now the airflow tends to lose its velocity and not stick to the very end of the car.
what this normally does it creates a low pressure zone at the rear of the car where the air is being diffused.

now if you have a high pressure zone up front and a low pressure zone in back,
that means there is resistance holding you back from accellerating easier through the air.
because high pressure tends to seek low pressure areas, energy travels the path of least resistance.
tend to wanna push you back in a sense.

but when you put say a small trunk lip spoiler on any car or get one of the roof lip spoilers from the factory,
they were designed in a wind tunnel to help reduce seperation at the rear and increase the high pressure zones,
resulting in less fuel being needed to remain at a constant speed (more noticeable at higher speeds),
which translates into mpg/efficiency increases depending on how you drive.



the pictures were from a study using vortex generators to help increase laminar flow and rear downforce while minimising coefficient drag increases.
they used them like tiny spoilers at the roofline of the rear of the vehicle to help reduce seperation of air from the body.
but the same effect can be seen with a good lip spoiler.


it may be one of those things that may not stand out to many.
but it will make a subtle difference.
you would probably notice it as being able to get up to speed marginally faster maybe even with reduced throttle input.

or say on some flat freeway your used to keeping your foot in a certain fixed position to maintain a certain speed,
then after installation you realise that the driving routine your used to and throttle pedal position you habitually drive in.
is netting you a higher mph than usual, so you ease of the throttle a tad bit, thus saving you fuel :-)

its the total car picture that will dictate mpgs, but every little thing adds up to a whole picture,
so from all the research ive done on spoilers, i would go for a lip spoiler/roof spoiler if possible on any of my cars.

but i dont think ill be adding any large trunk spoilers.
they are usually designed to offer more downforce rather than improved aerodynamics/efficiency.
and this trade off gives you some downforce at the expense of increasing coefficient drag thus reducing efficiency.

[bravekozak]

The spoiler is more of a status symbol, than functional.
The only reason I decided to put one on my car was to keep the sun and rain off the backlite.
I wish I knew how valuable spoilers were. In the past, I let a bunch of them go to the crusher.

[kumalaba]

over 130 mph charlie says they work.

[MrFishah]

Did somebody say spoiler?




Craigslist is your friend I'll admit though, I'm quite sure a spoiler like this will hurt your gas mileage...

[Damkid]

Did somebody say spoiler?



Craigslist is your friend I'll admit though, I'm quite sure a spoiler like this will hurt your gas mileage...

That thing is hideous....

[Safety Guy]

The main problem with those ricer rear wings is that they cost money.

If you want to add drag & turbulence and REALLY make your ride stand out for little or no cost, just cruise the alleys, collect discarded furniture and scrap, then bolt all of it onto the outside of your car.

There. Saved you at least $100!!

Karl

[MrFishah]

That thing is hideous....

I couldn't have said it better myself. Fortunately, hideous was the goal, so I take that as a compliment

[darrenryall]

If my contribution to a Kickstarter comes through, I might soon be able to get access to a 3D camera. And I've got two spoilers right now, one of which should be fairly easy to take off the car. If it comes through and I get the 3D camera as a result, the spoiler comes off and a 3D model is going to be made off the actual dimensions. Then it could be sent to someone with the capabilities to build new ones. That's my plan anyways..

[silverknight]

Damn...thumbs to rmoltis for such a great response.
Very knowledgeable here.
I'm lookin for one front spoiler and rear. Also rims. Something nice. 13 x 5.5 I think will fit.
Thanks silver.

[drddan]

I was wondering where you guys get the rear spoilers for the cars. Im looking at doing mostly for improved gas mileage. Is this something that actually improves gas mileage.

Here:
http://http://www.fordfestiva.com/forums/showthread.php?53702-2-new-lighted-Junspeed-spoilers&highlight=spoiler

Use the search function, there are a couple for sale right now!