Front Bumper Wind Splitter - DIY

[WRX8XB]

yeah, a metal frame that the splitter is attached to. You want more than a few bolts holding the spiltter together.

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[DatPanhandleWRX]

My question is, how did you get the STI front bumper splitters to fit on your wagon bumper? Write up or explanation please???

[PlasticFoamMan]

Instead of asking this question in a thread from over one year ago that obviously isn't being checked in on, PM the person you're addressing.

[68Cadillac]

Originally Posted by DatPanhandleWRX

My question is, how did you get the STI front bumper splitters to fit on your wagon bumper?

Rivets.

---

Had to scrap that High Density Poly Etheline (HDPE) only splitter. It just wouldn't hold up at 6mm thickness. I spent all that time and when tested, it wouldn't support even 10 kg before bending to the ground. Also tended to sag when heated up near the manifolds.

Lessons learned. For an upcoming HPDE I decided to revive my dream to make and fit a proper front wind splitter.

Sourced a sheet of 10mm Alumalite. Actually Econolite because I only needed one side with paint the underside could be raw aluminum. Saved a bit of coin by buying a damaged sheet. One corner was mangled, but well away from the area I needed. This stuff is stiff and surprisingly lightweight for how stiff it is.


Based the shape on my old HDPE splitter and a second splitter. There's the final shape after cutting against the wall.


Finalizing the placement of one of the seven mounting points. The bar stock for the mount is 6 mm thick. 38 mm wide.


3/32" 133-strand (7 x 19) Galvanized Steel Wire Rope for the three front mounting points. Breaking strength: 450 kg per wire. So together the three wires could lift up my car before they reached their breaking strength rating. I'm sure it'd just rip out the front bumper beam if it ever got near 1350 kg. But the wire wouldn't fail. Why wire? To allow a bit of upward flex in case of a nose scrape while on (off?) track.


Air dam to help the splitter build up high pressure right on top of it. Leading edge of the splitter sticks out 110mm from the bumper. I varied that 110 a bit for ascetics in certain areas.


Goes back 1.2 meters from the leading edge. Took a video to see if the wires needed to be tightened up but at 60 mph or so they straightened right out as the pressure differential increased.


Those are my foot prints. Did the "can you stand on it?" test. Hope it can it handle the pressure generated at HPDE speed.

[68Cadillac]

Still needs a bit more work.


But here's how it looks, this evening


Further back.

Driving impressions:

< 55mph or so the engine just sounds different. No butt dyno noticeable effects.

55 - 65 mph. Felt like the cars was gettin sucked down to the asphalt the way a house vacuum smooth floor attachment feels on tile when on the grout lines. Kind of stuck to it.

70 - 95 mph. Feels planted. Like a big shop vacuum with the same attachment on as above on smooth marble floor. Effort need to move the wand.

100 -105 mph. Felt stuck to the road. Like a magnet to the top of the fridge.

[68Cadillac]

Here's how the three front wire stays look from the side.


When I apply ~10 kg of force the wire slack disappears.

[802LGT]

Nice man, hope it works for ya

[mechatricity]

That looks hella functional. I like it. nice job.

[Blowby]

where did you get the sheet of econo lite?.....I have been looking forever to finish my splitter and that is all I'm lacking.


and subscibed

[my name is joe]

what did you use for the air damn piece? I'm always troubled finding this piece. Is flexible right?

[68Cadillac]

Originally Posted by Blowby

where did you get the sheet of econo lite?

Two places carry it in my area:
Interstate Electric and Montroy Supply. Montroy had a 10mm econolite white damaged sheet in their warehouse so I purchased from them.

If you need a list of distributes in your area email the manufacturer Laminators Inc: cheryl.leblanc@laminatorsinc.com

Originally Posted by my name is joe

what did you use for the air damn piece

Static-Dissipative UHMW (Ultra-high-molecular-weight) Sheet, 1/8" Thick

[68Cadillac]

Added a lip cap so I wasn't rolling 'round with sharp aluminum edges all round the lip. Glue and rivets to attach. Tape is temporary 'til the glue sets.




Custom made tire air dams. Probably a aerodynamic pipe dream that they'll work at the speeds I'll see at the HPDE. I set them to ride 20 mm of the road, which turned out to be a bit too low. The road is slowly sanding with every aggressive corner I take. Eventually they'll be ground down to the perfect height, but 'til then I'm dragin' plastic around every corner. If I' were to made them again I'd go 30 - 35mm off for a start.

[TwinscrollGT35R]

Wow Great job!!!

[68Cadillac]

Splitter Test to 105 mph

Splitter Test to 105 mph

Video of the testing session.

[KartRacer3]

Originally Posted by 68Cadillac

Video Link: http://www.youtube.com/watch?v=Cn0klVyfFxs
Video of the testing session.

Looks very sturdy! Props to you man.

[68Cadillac]

Here's how it looked in action.

Lap

Lap

Video of my best timed and videoed lap. I had faster laps but I didn't get video of it.

[DoogieSTi]

Super sexy man!! Does this replace your stock splash guard as well??

[Handsdown]

i'm wondering if the exposed hardware negates the aerodynamic effect of the splitter at track speeds. like, if it would just be better to use a more rigid material.

[Patrick Olsen]

No.

[Handsdown]

well i guess i don't mean negate... i know the splitter is going to still split the air to increase the velocity of the air that goes under the car and provide more downforce... i just mean that literally any splitter will do that as long as it stays rigid. i'm wondering if the exposed wires and bolts sap more speed through drag than would be sapped through inertia of a heavier material or extra cd of a different design.

my bad, i didn't word that well.

[WRX8XB]

Originally Posted by Handsdown

well i guess i don't mean negate... i know the splitter is going to still split the air to increase the velocity of the air that goes under the car and provide more downforce... i just mean that literally any splitter will do that as long as it stays rigid. i'm wondering if the exposed wires and bolts sap more speed through drag than would be sapped through inertia of a heavier material or extra cd of a different design.

my bad, i didn't word that well.

Splitters need drag to function correctly. (Drag/High Pressure up top, lower pressure down low)

[JSti07]

Here is mine. Can be put on in 7 minutes as well as taken off

[68Cadillac]

Originally Posted by WRX8XB

Splitters need drag to function correctly. (Drag/High Pressure up top, lower pressure down low)

Exactly. There's a pocket of dead air right in front-center of the car. Slow moving air = high pressure. Dead air = higher pressure. As the air moves to the side on top of the splitter it picks up a little speed but it's still slow.

Some of the air that would have hit above the splitter slips under increasing the velocity of that air passing under the splitter. Faster Air = Lower Pressure.

Here's a video of car in a wind tunnel showing this.

[68Cadillac]

Other than Alumalite/Econolite to make the splitter. If I were to make another one in the future I'd consider looking at:

Tegris . NASCAR uses this for splitters. It's pricey though.

or

Plascore AA3.6-80. Great because it has a hexagonal core. It's also recommended by Turn in Concepts.

or just lay my own up in Carbon/Kevlar with Divinycell Foam for a core

[Streetslappah]

Came out clean! Glad to know it does make a difference