Since this became such a heated topic on the neons forum, I decided to do some coast down tests between the stock airdam, and no airdam. The test was an A-B-B-A test, where the A tests were without airdam, and the B tests were with. For each test, I got two coast down times, one in each direction. Ambient temperature stayed at 64 degrees for the duration of the test, humidity at 39%. 3mph wind NW, test direction was East then West. Coast down speed was timed from 65mph to 50mph on an empty road. Tests were not done while cars were passing.
A 1- 22.3 sec 2- 20.6 sec
B 1- 21.1 sec 2- 19.9 sec
B 1- 21.4 sec 2- 20.1 sec
A 1- 22.7 sec 2- 21.0 sec
Average them together, and it shows a 5% increase in drag with the stock airdam on the car, vs without it.
This is the airdam in question. It is a stock piece. The issue is that without this piece, a stock neon would overheat. So the car needs a ducted radiator.
