Front Splitters: Do They Work?

[sfimirat]

Hi everyone,

My name is Mike and I'm from NYC. I hope this is the right place to post but I was wondering if anyone had any experience with front splitters. I'm really not sure if they do anything and if they're only for performance cars. I read that they can save you on MPG by reducing drag. Any thoughts? Is it worth it to put on a 10 year old Camry?

[Gasoline Fumes]

I have one on my recently-retired Civic Wagon. While I didn't do any accurate testing, it did seem to help on the highway. My theory was that it was directing air around the smoother sides of the car instead allowing it to cause drag on the rough undercarriage. I was careful not to make it too big, that would increase downforce and drag. Mine stuck out just slightly more than the bumper. Make a cardboard prototype and see if it works on your Camry! A vertical air dam is another approach.

[sfimirat]

Thanks for that! It's that your Civic? What did you use for the splitter and side skirts?

[aerohead]

The old-school research recommended the airdam.
Splitters were for the track only,and by default,induced drag,due to the downforce.
The reverse canting on my pickups nose produces measurable downforce even without a splitter.

[Gasoline Fumes]

Originally Posted by sfimirat

Thanks for that! It's that your Civic? What did you use for the splitter and side skirts?

The side skirts are Coroplast. Tire deflectors are baler belting. The splitter is the top of another Civic Wagon bumper cover. Perfect fit!

"aerohead" knows a lot more about aerodynamics than me, but I still like my splitter!

[freebeard]

Gasoline Fumes — Thanks for reposting that. Times past I've wasted whole minutes in Google's search function trying to find an example.

I think it's a good [possibly extreme] example of a central jet. There seems to be advantage to having most of the air under the car being sucked into the center. (Away from the wheels/tires?)

The way I see to improve it would be to have the deflectors twice as tall, up to the parking light, and vented to provide an air curtain over the front wheels.


As to the question at hand, they do work. They control the stagnation point if they are even with the body, and add downforce if they protrude ahead of the body.

[Gasoline Fumes]

Originally Posted by freebeard

Gasoline Fumes — Thanks for reposting that. Times past I've wasted whole minutes in Google's search function trying to find an example.

I think it's a good [possibly extreme] example of a central jet. There seems to be advantage to having most of the air under the car being sucked into the center. (Away from the wheels/tires?)

The way I see to improve it would be to have the deflectors twice as tall, up to the parking light, and vented to provide an air curtain over the front wheels.


As to the question at hand, they do work. They control the stagnation point if they are even with the body, and add downforce if they protrude ahead of the body.

I thought about air curtains! Tuft testing revealed pretty good over the wheels without them, so I don't know how much it would've helped.

[freebeard]

Here is my best attempt at an air dam. At least, the last picture I saved before something corrupted the file, which I never recreated.



The air dam is concaved to feed air sideways to the barge boards, which admittedly might should be bigger.

Based on observing OEM solutions, the outlet should be ±1 inch across the middle third of the wheel and the inlet can be any shape with a larger area to create a converging duct.

[slowmover]

Originally Posted by aerohead

The old-school research recommended the airdam.
Splitters were for the track only,and by default,induced drag,due to the downforce.
The reverse canting on my pickups nose produces measurable downforce even without a splitter.

Dude, . . . we all know it’s that bullet-shaped trash can lid you faired in to the grille center. (And we won’t mention the shortened F-86 sourced GE J79 turbine engine levers complete with quadrant you installed upside down on the headliner. He slams them forward as he hits the Big Road, with all the accompanying sound effects. That no one else can hear).

Splitter, barge boards (whatever). OP, it must be fun.

That little Civic hits the mark.

Good luck

.

.

[aerohead]

Originally Posted by freebeard

Here is my best attempt at an air dam. At least, the last picture I saved before something corrupted the file, which I never recreated.



The air dam is concaved to feed air sideways to the barge boards, which admittedly might should be bigger.

Based on observing OEM solutions, the outlet should be ±1 inch across the middle third of the wheel and the inlet can be any shape with a larger area to create a converging duct.

A problem might arise when there's any crosswind component attacking the nose.The sharp edge may trigger separation,whereas the original radius'd edges would not.There would be a low pressure leeward moment ahead of the front axle inducing yaw, which you'd have to correct for constantly with the steering.Not a problem on a closed race course.