What you're referring to is called negative camber. This allows for a driver to aggressively come into a flat or "on-camber" (by way of an outward lean from the apex) turn at speed. When the car begins to take a corner aggressively, the contact patch of the tire transitions, and if a cars wheels (especially the fronts) "lean" out, then the contact patch can remain, due to the transfer of weight. However, if the cars wheels lean in, then even less weight is shifted onto a contact patch, and this can therefore reduce traction.
Negative camber is effective only when calibrated to adequate performance levels and needs. Too much can result in more problems than one need deal with.
How much will lighter wheels improve a car's acceleration time?
Less than double their weight savings as a percentage of the total.
10 pound per wheel reduction, 40 pounds for all four, 80/3000 pounds total weight < 2.7% shorter time to speed.
The difference between rotating and static weight goes from 0 to double moving from the rotational axis to the road surface. Obviously, you won’t have any wheel mass closer to the road than the tire bead.
Does a muffler improve acceleration?
Real Sports exhaust systems can add power if the exhaust was a weak link before and they can help make more use of other mods and therefore increase power.
However that loud back box that gets you all those angry looks from your neighbors is more likely to be reducing power output. If you have no muffler at all, it does not neccessarily mean that you would have more power, as mufflers are designed as integral parts of a tuned exhaust system.
The car exhaust system has two main components namely the Catalytic converter and the Muffler. The main purpose of the car exhaust system is to vent the gases which are a byproduct of the combustion process into the atmosphere. The catalytic converter is installed in the exhaust system before the muffler and it's purpose is to convert more toxic gasses in the exhaust (like NOX, CO, So2)to less harmful from like co2, water vapor etc.
The Catalytic converter has a Platinum or a Palladium catalyst which aides in this process. The purpose of the muffler is to reduce the sound of the exhaust. The muffler has a set of pipes of varying length which dissipates the Shockwaves present in the exhaust stream which will reduce the noise level.
Getting the right exhaust for the right engine is open to a lot of debate. It depends on the type of vehicle you possess. Removing exhaust restriction generally improves performance BUT it is not a uniform improvement. With a simple removal of restriction, typically there is an improvement in the “top end” higher rpm and possibly a loss at the lower rpm.