Hood up versus hood down RWHP question

[jrkermode]

The stock Viper intake grabs a lot of air from under the hood. I've heard that every 10 degree increase in intake temperature results in a 1% loss in HP. Does anybody have any real world data on this? For example, dyno pulls with the hood up versus with the hood down?

 

[Jack B]

The hp is corrected for ambient air temp by the dyno's computer. The Viper's coolant temp is the key. You will probably get better cooling with the hood down if they have a high velocity fan blowing into the lower grill area.

 

[Venom Lover]

I have dyno'd in the same session with hood up and down to see if it made a difference, and the answer is no. My two runs were within a couple hp of each other across the curve, with the peak hp numbers being identical. Coolant temp does seem to matter, however. If coolant temp is high, expect about a 5 hp hit.