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Let's Talk Aero

AJ, am I safe to assume that a car without the fenders vented sees no improvement from the ducting on the splitter that is leading to the wheel well. If the air doesn't have any place to go, it will stagnate. No flow equals no downforce.

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No, you will still get some benefit without the fender louvers or tire reliefs, just not as much. Air will still make it out, but you are correct that it will be more difficult to get out.
 

Bill Pemberton

0ld Ford Automotive Racing Terror
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Glad you posted, it reminded me I need to save even more after Christmas since AZBoss and Dean Palmer ( my fabricator ) both told me I need a set of your dive planes. My poor wife thought I was done adding things to my race car , but I have become good friends with Tymeslayer and we all know he can not stop accessorizing. Must be some virus I caught from being around him, ha?
 
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Hey Gents,

I worked on a splitter over the past weeks, tested it and evidently broke it, as expected.

Overall this has been a big and fun learning exercise. Lots of time was spent figuring out how to mount it, add quick releases and anchor it all around. It is very big right now, actually it is way too big as I left a bunch of space for the tunnels which are inbound. Please take the dimensions with a grain of salt, it will all be trimmed down later on.
That said, this was still great for testing clearance, anchoring etc. and I´ll keep using the current blade to test fit tunnels.

Couple takeaways:
  • Aluminite is very floppy and the backing bolts will press into the blade while the pucks will punch through it. Gonna look for other materials.
  • CF rods that hold a lot of weight will need a lot(!!) of torque, else they can slip and make the blade sink. Always mark your rods!

83"x48". The rear end happened to match up with some rails in the chassis which I was able to hook the splitter into.
1622305404492.png

1622307447452.png

Titanium pucks kept the splitter off the ground and entertained with sparks. Fun while being, but scraping is something I´d like to avoid on a frequent basis.
1622305348118.png
1622307697093.png


Front pucks started to eat into the alumalite blade.
1622305435870.png1622306225866.png
1622306173172.png


General question:
How far back should the splitter go? Currently it stop after the oil pan, which is pretty deep and allows for a lot flat surface. But also would be very heavy when going back to plywood or similar.
 

Mad Hatter

Gotta go Faster
4,010
2,507
Santiago, Chile
Hey Gents,

I worked on a splitter over the past weeks, tested it and evidently broke it, as expected.

Overall this has been a big and fun learning exercise. Lots of time was spent figuring out how to mount it, add quick releases and anchor it all around. It is very big right now, actually it is way too big as I left a bunch of space for the tunnels which are inbound. Please take the dimensions with a grain of salt, it will all be trimmed down later on.
That said, this was still great for testing clearance, anchoring etc. and I´ll keep using the current blade to test fit tunnels.

Couple takeaways:
  • Aluminite is very floppy and the backing bolts will press into the blade while the pucks will punch through it. Gonna look for other materials.
  • CF rods that hold a lot of weight will need a lot(!!) of torque, else they can slip and make the blade sink. Always mark your rods!

83"x48". The rear end happened to match up with some rails in the chassis which I was able to hook the splitter into.
View attachment 65521

View attachment 65526

Titanium pucks kept the splitter off the ground and entertained with sparks. Fun while being, but scraping is something I´d like to avoid on a frequent basis.
View attachment 65520
View attachment 65527


Front pucks started to eat into the alumalite blade.
View attachment 65522View attachment 65524
View attachment 65523


General question:
How far back should the splitter go? Currently it stop after the oil pan, which is pretty deep and allows for a lot flat surface. But also would be very heavy when going back to plywood or similar.
Yeehaa, thats quite the splitter!! Our tracks would be unforgiving for something that low. I would be careful about taking the splitter too far past the oil pan. Gets really hot!!
 
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Yeehaa, thats quite the splitter!! Or tracks would be unforgiving for something that low. I would be careful about taking the splitter too far past the oil pan. Gets really hot!!
Mine stops at the pan.
 
87
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Yeehaa, thats quite the splitter!! Or tracks would be unforgiving for something that low. I would be careful about taking the splitter too far past the oil pan. Gets really hot!!

Good point! I would not mind going shorter as all that surface comes with a lot of weight depending on the materials. Or making a two piece that has a lighter material in the rear.

CF rods and pucks help a lot with uneven surfaces. I was surprised about the amount of scraping I heard and how mint the splitter stayed till the rods started to slip.
 
4,443
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Pleasanton: 1/2 way between Sonoma and Laguna Seca
Work of art dude! What material is that? It looks a but like it`s made out of multiple elements.
The splitter is .150 aluminum and the belly pan is .085 aluminum.
 
Nice work!

From what I’ve read the farther back you go the better. Just depends on what’s feasible and if you have enough cooling and venting out the hood.

My 1/2” plywood splitter is not a big as yours but lighter than I was expecting. For how cheap it is now that you have a template might be worth a shot. Also you can radius the front which AJ Hartman says is very important to prevent airflow separation. He actually doesn’t recommend alumalite for this reason.
 
87
151
SFV
Nice work!

From what I’ve read the farther back you go the better. Just depends on what’s feasible and if you have enough cooling and venting out the hood.

My 1/2” plywood splitter is not a big as yours but lighter than I was expecting. For how cheap it is now that you have a template might be worth a shot. Also you can radius the front which AJ Hartman says is very important to prevent airflow separation. He actually doesn’t recommend alumalite for this reason.

In a futile attempt I tried to radius alumalite, did not work at all. I had plywood splitter before and that thing was a beast. Indestructible. Looking forward to get back to plywood. What bit did you use to radius your splitter?
 
Nice work!

From what I’ve read the farther back you go the better. Just depends on what’s feasible and if you have enough cooling and venting out the hood.

My 1/2” plywood splitter is not a big as yours but lighter than I was expecting. For how cheap it is now that you have a template might be worth a shot. Also you can radius the front which AJ Hartman says is very important to prevent airflow separation. He actually doesn’t recommend alumalite for this reason.
Did you use regular ply or something like birch or marine ply ?
 
Did you use regular ply or something like birch or marine ply ?

I wanted to use marine ply but I didn’t know how good the splitter would turn out and marine ply is like $130/sheet here so I opted for birch from HD. Marine is supposed to be lighter and more water resistant though so now that I know it will turn out well my next one will prob be marine.
 
I wanted to use marine ply but I didn’t know how good the splitter would turn out and marine ply is like $130/sheet here so I opted for birch from HD. Marine is supposed to be lighter and more water resistant though so now that I know it will turn out well my next one will prob be marine.
I work at a major airline as a mech and we wave a composite shop. I want to make a plywood splitter and have the shop add carbon fiber layer to it.
 
4,443
4,209
Exp. Type
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Pleasanton: 1/2 way between Sonoma and Laguna Seca
I work at a major airline as a mech and we wave a composite shop. I want to make a plywood splitter and have the shop add carbon fiber layer to it.
why not use foam board and carbon cover that like AJ Hartman does and have a super light/strong part?
Or, use aluma-light for the form and cover that with CF?
 

Grant 302

basic and well known psychic
Also you can radius the front which AJ Hartman says is very important to prevent airflow separation.
This isn’t all that relevant for materials say under an inch in thickness. It’s also incorrect to say that it (any rounding or radiusing) will ‘prevent separation’ with an otherwise flat splitter. There will still be separation under the splitter downstream. More so with any tunnel as he advocates.

Ultimately, it can even reduce downforce by raising the effective profile of the splitter and and accelerating the underbody air less than one with a blunt edge.
 

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