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:
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:
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:
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.
