A well made splitter will increase the relative pressure above it, thereby increasing the pressure differential across your radiator (assuming it is decently ducted) and increasing cooling. This will happen regardless of hood vents, however hood vents will generally reduce relative engine bay pressure, thereby also increasing the pressure differential across your radiator and further increasing cooling.

 

I'm just throwing it out there. Bamboo is relatively new in the industrial/commercial use front. It is extremely strong yet flexible, and long-strand. It's probably the closest thing nature has to carbon fiber.

Why not use 1/4" bamboo sheet used for flooring as splitter material? I'm going to assume that it's treated for water, but all the other characteristics seem like a natural fit for a splitter.

Paint it black and go.

 

I can't imagine 1/4" plywood of any sort is stiff enough to use for aero parts unless it's skinned with something...

 

For a splitter it will need a couple supports forward of the car. But if you rigidly mount the splitter to the car under the car and run a couple spoiler supports forward it more than enough. You want it flexible enough that it wont just crack when you nail a cone or a curb or you kick the **** out of it after it annihilates your ankle when you're working on the car.

 

Just trying to think outside the box. Bamboo is phenomenally strong, although it would probably be a good idea to coat it or put at least one underlayment of fiberglass on it. I'd run a couple of clevis mount supports on the front, just like with any other material.

A little router on the edge and I think you'd be in business.

 

Luan/Meranti works well. light and quite strong.

 

To build your own you could use thick corruged cardboard and do a couple layers of wet lay up with fiberglass. It may sound ghetto, but once the fiberglass in dried all over the cardboard, the cardboard becomes almost nothing but a spacer, but the thickness and the distance between the two glass skin makes it stiff. It would be really cost effective and easy to do. You can always do a mould later on after you find the perfect design and do then with cooler material like carbon fiber and better honeycomb than cardboard. You can also use a epoxy-fiberglass composite to save cost on the standard epoxy-carbon fiber and still have way better properties than polyester - fiberglass.

 

How about aluminium? strong and easy to work with

 

12mm birchwood is significantly stiffer than 1/8" aluminum and is still 13% lighter for the same dimensions. Aluminum is also expensive for a large sheet and comparatively difficult to work with (compared to a simple sheet of plywood).

Birch > *

 

Birch, birch, birch. There's no better direction to go other than composites (lighter, easier to do complex shapes), and that is only if you're willing to swallow the cost and time that will come with replacing it every time it gets damaged.

I've repaired my same birch splitter 4 times now. I take chunks out on curbs or from rocks when I have an off, go home and unbolt it, fill in the missing chunk with bondo-glass, sand it a bit, spray some rustoleum flat black, and it's good as new.

1/8" aluminum would bend the first time you nailed a curb or cone.

-Ryan

 

My 12mm plywood splitter, with aluminium angle spars, weighs only 7kg. I was considering aluminium or alucobond but the arguments in favour of sticking with 12mm ply were too strong.

I crashed my car 4 weeks ago, wiped out the right fender, inner guard, hood and nose. Radiator support bent to hell. Even bent the right upper control arm. The plastic crusher front is obviously a write off... But apart from pulling out some of the self-tapping brackets holding the plastic in place and scuffing my $5 rattle can paint job, the splitter survived.

12mm plywood is strong, light and cheap. For the sake of a kilo or two, you can't do better.

 

I will go with birchwood. Thanks for the info guys

 

I've been using two layers of 5mm underlayment which I believe is birch, Chinese stuff from Home Depot.

I laminate the two layers together myself with wood glue. The part that sticks forward of the air dam is two layers thick, The part that closes out under the car back to the front sub-frame is one layer thick. Saves about 1/3rd the weight that way.

Autocross version is just painted with epoxy resin to seal it then rattle canned. Track version has one layer of fiberglass top and bottom. Makes it relatively water proof and more durable. Polyester resin is cheap but sucks. Impacts and scuffs with polyester fray the fiberglass and it doesn't stick as well doesn't wet the glass or the wood well. Epoxy resin is expensive but it is the **** for making all the composite components behave as one piece.

 

Bob, consider spraying it with polyester gelcoat next time. Thats worked well for both my splitters, adds color and protects, it doesnt chip off either. You need to spray it though, it looks like *** if you try to brush or roll it on. I think I might copy your DIY 11mm plywood method though because round these parts you have to get 3/4" or 5.5mm birch to get a piece thats flat or just deal with 3/8" southern yellow pine, which is whats on my car now, because it was the lightest thing I could find that was flat. I was also considering using just 1 piece of the 5.5mm birch underlayment with kevlar and epoxy resin in the rub areas on the bottom (because abrasion resistance) and bi-axial carbon or just E-glass on top. I'm just fearful that it will make the splitter too stiff and brittle and cause it to break rather than bend when I beat the **** out of it.

 

The Chinese underlayment stuff is the flattest sheet I can find here. 5.0mm says moister resistant. Looks like the birch, may have a paper thin layer of what looks like mahogany on one side very smooth sanded both sides. Cost about $12 for a sheet. Bout the cheapest 4X8 sheet of anything they have.

Unlike the So-Cal crew resistance to rain soak warpage is a major concern around here Epoxy seems to be the best thing I have found to prevent moister absorption. Lots of hand built wood boat builders around here and that is what they use I believe for a reason.

 

Yeah thats what I figured you were talking about. I think its called lauan. Its mahogany on one or both sides but birch in the middle.

 

Check AircraftSpruce for lots of exotic plywood options.

 

Sure but have you tried shipping big sheets of plywood? O_O

 

Need to hit the hardware store.

 

Mine is made out of Alumilte or something like that. It's Aluminum on the outside with plastic honeycone in the middle.

It seems to deal with curbs ok and I even mowed the lawn from 8 to 9 at Sonoma with little damage.