Aerodynamics - Mind Your Boltheads

We spend thousands on swanky carbon bits to go under the car to promote downforce. Funny thing about under car aero is that it's sensitive to the smallest things for it to work its best...

A couple key points about under car aero (ground effects) are:

• NEVER put a lap joint at the entry to the diffuser. (Thanks Lotus)
• If fasteners must be used, ALWAYS use fasteners with the least amount of protrusion into the airstream. Button heads, rivets, are all acceptable. NEVER use hex head or standard internal wrenching head bolts...

So this is simply about the details. For instance, the swanky/expensive Reverie front splitter came with standard head internal wrenching bolts. They stuck down a good quarter inch into the air stream. See the comparison pic... Now, it's not like a couple bolt heads are going to make a big difference in your lap time--- or will they? (placebo effect???) If one spends a few grand on aero, one may as well make sure he's getting the greatest bang for the buck...

So replace the standard head bolts with button heads...

Replace the stock diffuser/undertray bolts to hopefully help airflow there as well...

Bolts can be purchased at mcmaster.com. You need M5x20, M6x20, and M8x25x1.25

Again, not looking for big gains with something like this all by itseslf, but if we pay attention to the little details all over the car, the aggregate can make a big difference...