Okay we just got some Dyno numbers in. We might make another run just to compare other intakes.
Here are the results from a 1996 NSX Stock with 100,000+ miles on a Dynapack 3000. Measuring the HP from the wheels with 0% correction for the transmission. There are a few items in the dyno that didn't make sense so if anyone wants to dyno test and post their own results, please do. The operator told us this dynometer generally provides lower HP results (more conservative). I would like to go by % rather than HP as it seems to be more logical that every NSX has different HP at any given dyno runs.
Baseline Stock NSX: 218.2 HP
Baseline w/ Unifilter Drop In: 222.1 HP
Baseline No Filter / No Box 198.2 HP
Carbon Intake Mugen Filter: 222.7 HP
Carbon Intake Hi Flow Filter: 224.6 HP
Carbon Intake Clean Flow Filter: 226.4 HP
Baseline Stock NSX: 216.3 HP
Baseline Stock NSX: 216.1 HP
Here are the puzzling results. The more restrictive filter yielded the highest HP and was third to the last run. By the end of the run we wanted to see how much HP was showing at the end and it was about 1.7 ~ 1.9HP less than the first run. Perhaps the car was getting hot, coolant levels were fine and stable. No overheating issue. The rear hatch was left open. No air was blown into the side vent. There was a fan cooling the front radiator. The unifilter netted a 3.9 HP gain. When we removed the airbox and filter it resulted in a 20.0 HP loss. Each run was conducted approximately 5 minutes apart once the car was setup. There were about 4 test pulls done before we got any numbers out because they were dialing the settings such as the gear ratios, control speed, rpm sync, etc. We have pictures, but I don't have them with me because I didn't bring a camera.
So the results are that it does work. Depending which baseline HP you believe is correct the results vary. HP gain is this stock NSX is from: 8.2HP to 10.3HP. The reason we dyno in this order was from laziness you can pretty much see what we did and we didn't want take things on and off twice.
Notes from the graph. The Torque graph showed more torque improvement right away from the very starting 2000 rpm to 7555 rpm. The only rpm range where the Torque was close to the stock was at peak torque 4,550 rpm. The power graph looked pretty close to each other. The HP started to show increase at 3,700 rpm of around 2-3 HP gain by 5,500 rpm the power gain is 5 HP. The peak power was around 7,700 rpm. So the power gain is has a somewhat wide spectrum. The sound is very noticeably different, the guys all liked it. The clean flow filter is superior in cleaning efficiency than the cotton gauze in the Mugen filter. Our foam filters outperformed the Mugen filter. Since the baseline on this car is so low, I would prefer to use the % gain instead. I believe if the car had a higher baseline the HP would be higher. Since this product does net power and looks bitching I am glad to announce that I will begin selling this product.