5 Cheap but Effective Aero Mods
If you can’t afford to test and tune or buy expensive proven aero kits, here are some ideas to consider.
Frontal area is critical to aerodynamics and can be described as the amount in square feet your car takes up when viewed from the front on a 2-dimensional plane. Side mirrors are $0 to remove and take up approximately 3-6% on cars like the S2K. By removing them, you can gain tiny aerodynamic advantages that may increase top speed in the form of drag reduction. 6% is a lot when it costs you nothing, but this is obviously a track-only modification. Do not do this on the street unless you like tickets. One study from GM in the late 90s was shown to reduce total Coefficient of drag by 0.03 just from reducing the size of side mirrors.
Rear wheel covers are probably the coolest DIY mod anyone could pull off. Not only do they transform the look of a car, but they reduce drag and can be seen on everything from JDM tuner cars that participated in top speed Wangan runs to hypercars like the Mclaren Speedtail which has purpose-engineered wheel covers at the front. Obviously, brake cooling is a factor. So the balance between reducing drag and managing temperature makes this one a bit tricky, but it’s strange this modification hasn’t got more attention in the aftermarket scene.
Front Splitter and Proportioned Wing
A modest front splitter that has an extended undertray will help in accelerating airflow underneath the front of the car. Many do-it-yourself guides can be found, but be careful of who has tested and proven their home built designs and remember: aerodynamics are about balance, so you want to do these two modifications in phases with each other in order to not affect your handling bias from front to rear. Avoid huge wings on stock power levels as you can add drag and end up harming lap times. Wing risers can help to move the wing closer to the S2000s roofline which puts it into cleaner flowing air.
If you’re going to buy a wing, you need to buy endplates to help channel air more efficiently over the wing. Reputable aero companies will have some kind of option that you can add onto the wing and it’s highly suggested. Bigger is better within reason (don’t go full Fast and Furious) and they are typically cheap to add on for the extra performance they deliver.
Hardtops help channel airflow over the car and reduce turbulent air. Many OEM tops can be found for around $1,000 on eBay which can both reduce weight, if you remove the soft top mechanism entirely, as well as help make your vehicle slice through the air a little bit easier. If you’ve done other modifications to the car, this is a great way to tie everything together from an aerodynamic perspective. All it takes is one look at top level time attack and autocross cars to confirm this. Hardtops are everywhere!
Small things add up to big gains when it comes to drag reductions on a vehicle. You may not notice it or feel it, but the stopwatch will confirm the changes or refute them. Removing radio antennas and even shaving door handles can be used to gain fractions of an edge over the next guy. Now get to work.