I had a belly pan fabricated for my E92. Initially problem was my rear diffuser warping from parachute effect at freeway speeds and higher. Had a front pan piece also made while it was being done.
Goal was to a address a few issues or improve where possible.
1) Seal the rear bumper
2) Vented engine pan to allow air to escape and minimize engine bay pressure. Better cooling back thru cylinder 6.
3) Vent for IC and radiator air flow.
4) Duct for transmission. allow as much air flow as possible with rear trans vents.
5) Increased size of all stock tire air diverters. Tires amount to approx. 30% of overall drag :think: (might be making that $#@! up but seems like I read that somewhere). Increased both width and height of stock rubber diverters.
6) Pan has a tiered set up so each section served as a vent for next section.
7) Lightweight aluminum but thicker then tin foil.
Some photos during fab. Will get try to get some final pics next time I get the thing on jack stands or lifted.
During the whole design one thing came up that some of you can take from this thread. Your stock cowl prevents high pressure air in to the engine bay. Removing it effectively creates a wall of pressure in your bay, that reduces amount of air able to pass through ducts/radiator/IC. The shape of the stock cowl is perfect. Edges are open allowing venting, center high pressure area is sealed. Removing it is counterproductive.
Goal was to a address a few issues or improve where possible.
1) Seal the rear bumper
2) Vented engine pan to allow air to escape and minimize engine bay pressure. Better cooling back thru cylinder 6.
3) Vent for IC and radiator air flow.
4) Duct for transmission. allow as much air flow as possible with rear trans vents.
5) Increased size of all stock tire air diverters. Tires amount to approx. 30% of overall drag :think: (might be making that $#@! up but seems like I read that somewhere). Increased both width and height of stock rubber diverters.
6) Pan has a tiered set up so each section served as a vent for next section.
7) Lightweight aluminum but thicker then tin foil.
Some photos during fab. Will get try to get some final pics next time I get the thing on jack stands or lifted.
During the whole design one thing came up that some of you can take from this thread. Your stock cowl prevents high pressure air in to the engine bay. Removing it effectively creates a wall of pressure in your bay, that reduces amount of air able to pass through ducts/radiator/IC. The shape of the stock cowl is perfect. Edges are open allowing venting, center high pressure area is sealed. Removing it is counterproductive.