I am about to shock the board with our results of the air intake systems.
First I need to say this. Our company always does testing of new products by dyno, on road and on the track with data logging and timing before we can release a product to the consumer. Seat of the pants or guessing is not what we do here. There always has to be data behind to prove the results. We decided to put the whole intake thing to a test. By the way our company has designed the Vortex Ram Induction Systems for C4, C5, C6 and Z06 Corvettes that produce over 30 hp. We have our own race team and support several others in the Corvette industry. We decided to develop a couple of air intake systems for the Smart car to see what it would give. Here are our results. By the way we designed them like the 2 currently out on the market.
Here are the results:
Performance Intakes
0-60 15.5
0-80 28.0
Intake temp 132
load 95%
Factory system
0-60 14.0
0-80 24.0
Intake temp 104
Load 97%
We ran about 3 passes of each system and this was the average. Outside temp 89 degrees
Bottom line is the factory system is sealed from the engine compartment and pics up cooler air from the outside scoop.( like our Vortex Systems for the corvettes )
Where ever you place the filter on the performance systems the temps rise.

If you first start the car it is ok but drive it for 20 min and see what happens. When IAT go up the timing curve goes down and so does the power. You would have to place the filter and 10 inches from the ground to get away from the heat build up. Then you have another issue WATER!!

The factory system is well designed so we will be taking another approach. We will try to ++++++++++++++++++++++++++++++++++++++++. Opps we can not give out that info yet...lol
We hope to work on this in the next several days and will post all the date before releasing any products. VERY SIMPLE WATCH THOSE AIR INTAKE TEMPS..
Ernie