Dyno Vs.Drag Strip Testing

gregsdart said
I have what i thought was a well sorted out air intake system. A a dominater aircleaner base and stacked nascar 14x3 filters. A large hood scoop and good seal . i felt my car was 2 to 3 mph slow for the dyno numbers, at 151.5. I had some problems and opted to run without the hood or aircleaner, just the scoop. The aircleaner showed a 1 hp los on the dyno, so i assumed it was quite efficient. But the car went 154.32, or 3.8 mph faster!
So i assume it muat be aerodynamics/airflow around the front end that made the difference.

I doubt your car became more aerodynamic without the hood. I suspect your scoop is making the air entering the carbs VERY turbulent. The reason I say this is I have a Bonneville land speed customer with a 439CI 1st Gen Hemi making well over 800HP NA with 2 carbs. He battled scoop issues and figured it out because after a 3 mile run the firewall and windshield was covered in a red liquid that turned out to be the fuel they have to run in his class. The carbs were getting all kinds of wacky air movement at 200+ MPH and actually spraying fuel anywhere but down the sheetmetal intake. He ditched the forward facing scoop the following year and picked up big time and no more fuel on the firewall/windshield. I have also seen this in a tunnelram street application--where the guy removed his little tiny air cleaners to do some fiddling and the car ran like crap just driving normally down the road. He reinstalled his little air cleaners and the car ran perfect again. The conclusion was the air cleaners straightened out the air entering the carbs and the carbs liked it. Just some of my experiences. J.Rob