Belly Pan/Splitter/Diffuser Project
 

Thought you guys would dig this. In this case I did not do these mods for mileage, I did it for top speed/safety. But the same principals apply obviously.

This was done on my 2007 Mustang

Front Splitter:

http://i767.photobucket.com/albums/x...ps20bf1869.jpg

This was done for a couple of reasons. It does provide a little downforce (or maybe less lift). It also helps out by dragging air out from the engine compartment so my coolers (which there are a LOT of) work better. And the obvious, less drag. It runs from about 2” in front of the factory “splitter” back to the radiator support (back side of radiator). It’s made from Sintra and very sturdy. I can stand on it without it being deflected.

Engine Compartment/Radiator Heat Extractor:
You can see it in the pic of the splitter above

This is actually a OEM piece off of a 2010 Mustang that I re-purposed for this project. The way that it is set up there is a low pressure zone under it created by the splitter. This extracts air from right behind the radiator (and heat exchangers). I have no choice but to move a TON of air through all the coolers so to keep aero drag down and reduce lift I have to evacuate as much air from under the hood as possible. This piece pulls some out of the bottom of the car. The hood is also very vented to move evn more air/release pressure.

Belly Pan:

http://i767.photobucket.com/albums/x...psc7832ca9.jpg

http://i767.photobucket.com/albums/x...ps9846c590.jpg

http://i767.photobucket.com/albums/x...ps828a1b17.jpg

The belly pan is 6mm aluminum honeycomb. This was a LOT of work (50 man hours). There are a lot of brackets involved in getting this to fit up nice and flush and be sturdy. Plus, since it is a race car that gets worked on all the time they had to be easy to remove. And they are. I can have them off in 2-3min. The pans are heat shielded (the silver stuff) around the perimeter and the exhaust is wrapped so I don’t screw the pans up. If you look at the pans from the side (hard to get a pic of) you will see that there is only about 1/4” exhaust tubing hanging down below the level of the pan. We considered running the pans under the exhaust but we wanted the ground clearance and really didn’t want to find out the hard way that there would simply be too much heat to deal with. The pans, brackets and fasteners only weigh 18lb.

Rear Diffuser:

http://i767.photobucket.com/albums/x...ps4d5be4e0.jpg

This pic is of a diffuser we did on my buddies car. This one is more for looks with the bonus of being functional. We have already made the main part of the diffuser for my car, and it is very similar to the one pictured. But because my exhaust dumps at the axle the diffuser will run all the way from edge to edge. We will also be removing/raising the bumper cover about 4-5” behind the wheels to “vent” the rear tires. This will all be sealed in. And in true race car fashion it’s all set up to come off in one piece with 10 fasteners. Should only take a couple of minutes. The diffuse is made of Sintra just like the front splitter.

Axle Ski’s:

We will be making these last (no pics yet). Basically we will be making a belly pan that attaches to the axle and bridges the gap between the fuel tank (which is “part” of the belly pan) and the rear diffuser. The leading and trailing edges will have a little “kick” up to them so as the axle travels up and down it won’t scoop air. It’s the only solution we could come up with to work around a live axle. It will be pretty easy and not weight much of anything though. The only issue will be to run enough heat shielding to where the exhaust outlets won’t melt it.

I have no real test data. One, I'm not done with everything. And two I don't get to many chances to run the car up over 200mph. That said, after the belly pan was done and I had a "half measure"/mock up diffuser on it felt a lot more planted and didn't move around nearly as much at 200mph as the previous time I had it that fast.

I suppose when I'm all done with everything I could do some coast down testing. I can pop everything off in 15-20min.

Just thought you guys would dig it. It’s clearly not “budget”, and not intended for mileage. But as far as aero goes I think this is what a lot of you are trying to accomplish.:thumbup:

Excellent work and craftsmanship, thank you for posting this. I especially like your attention to the details related to the heat produced by the exhaust. How sturdy would you say the honeycomb panels are? Where did you source your aluminum honeycomb and sintra, and can you give us a ballpark on price for the raw materials?

VERY impressive!!!
I'm impressed! (and humbled)

Can you do a street view of the front splitter?

Beautiful work and attention to detail. It could pass for factory, but in my opinion even better.

regards
Mech

Thanks! We put a ton of hours in this stuff (too many really). It's nice when people notice.:thumbup:

I don't have a whole lot of "top side" shots. The car isn't "done done" so I don't take many pictures. Here is one that gives you an idea of how it looks from the top. It's pretty stealth. Just ignore the hacked up hood vents. I was testing them at the time and didn't feel like making them pretty if they didn't work out how I wanted them to.

http://i767.photobucket.com/albums/x...ps4ef2416b.jpg

Just sold this car. This was the pretty one (not real fast though). Really cool splitter. It's carbon fiber with a foam core and internal aluminum skeleton so those tow hooks on the front (which are titanium) are functional. Lots of hours in this car. It's been in a couple of magazines.

The blue car has a hood like the silver car now. I wanted to do something different because a lot of people run that hood. But it's so good at what it does there wasn't much point in re-inventing the wheel.

http://i767.photobucket.com/albums/x...ps967b8d78.jpg

The stuff isn't horribly expensive, it's the shipping that kills you.

I think the aluminum honeycomb was $160-180 for a 4x8 sheet. I bought two not knowing exactly how much I would need and it was 2hrs away so I didn't want to take multiple trips. I ended up only using one. So I have one in the rafters for some future project. I got it from a place called Plascore over on the west side of Michigan. Here is a link:

Honeycomb Panels - Lightweight Honeycomb Panels - Lightweight Panels

We pick the sintra up from a local plastics place, and for the life of me I can't remember the name. We just drive over and get some when we need it. And I can't remember how much it is either. I should, we bought a ton of it for all sorts of projects. I want to say the 1/4" stuff is $85 for a 4x8 sheet. The diffusers are made from multiple pieces/layers of that. The 1/2" stuff is $140 for a 4x8 sheet???? That is what the splitter is made of. You can bond two layers of 1/4" to get one 1/2" splitter though.

You can get two complete splitters out of one 4x8 sheet. With all sorts left over for closing up little spots.

Sqidd,

I'm a big Ford fan and bigger Mustang fan....thanks for the vicarious experience!

ps. I added your thread to my Q45 belly pan thread.(third in my sig)

I'm in love with this thing... Truly a great car, a great project, and amazing fit and finish!

Please do post up pics of the axle pan when completed! I am planning a full body pan for my SUV, and the axle causes me trouble when thinking about air flow under the truck.

~C

Since you haven't posted your diffuser yet, I'll throw this out there:

http://ecomodder.com/forum/member-fr...bonnevette.jpg

It is a divergent duct. If the top were similarly curved it would mimic half of an exponential horn speaker. Those couple to the ambient air very well. I wonder whether your speed whisker abaft the rear tire does much. I think pulling the underbody air out to the sides would eliminate a lot of wheelwell turbulence.

Do you think the speed whiskers on the front corners help?

And have you worked with materials like Polymetal/Alumilite/OmegaPanel (aluminum skinned themoplastic)? Thanks for the Plascore link. Here's another: inrekor™ | ultra lightweight sandwich panel technology

I just read your thread, nice work! That is a lot of effort and fiddling around. I can appreciate all the work that went into that.:thumbup: