My new heat extractor hood

[racebronco2]

Great work. I'm following with intense interest.

As some of you might recall, after boxing my radiator and putting in a massive oil cooler in the drivers fender, I solved my heat problems... only to create an aerodynamic problem at 160+ (front-end lift). I'm stuck in the 140 mph class (110-168 range) in ORR until that is solved. I'm not wanting to throw money at the problem until I have a reasonable chance that the money will help.

So... I'm hoping that the hood testing will help us arrive at a reasonable solution to reduce front-end lift.

When i open track my car i use a splitter which also blocks off the portion between the bumper cover and the radiator support. For high speed runs i remove the splitter so the portion between the bumper cover and the radiator support is open. The modded hood is a proven performer whether it be open track or high speed runs. The highest speed i have been is at 172.xx mph and it was as stable as it was at 120mph. Below is a video of me doing 172.xx
2004 comp orange cobra at the mojave mile - Car Videos on StreetFire

 

[haskett]

If it were my car I would block off the upper
grille opening and cover the headlights/front lip of the hood with a large
piece of helo tape, vent the fenders and install an air dam with small
splitter.

Thanks for the feedback. Wouldn't blocking off the upper grille opening create cooling issues? What is the purpose of venting the fenders, since the air is trapped under the hood, not the fenders?

When i open track my car i use a splitter which also blocks off the portion between the bumper cover and the radiator
support. For high speed runs i remove the splitter so the portion between
the bumper cover and the radiator support is open. The modded hood is a
proven performer whether it be open track or high speed runs. The highest
speed i have been is at 172.xx mph and it was as stable as it was at 120mph.
Below is a video of me doing 172.xx
2004comp orange cobra at the mojave mile - Car Videos onStreetFire

Thanks for the feedback. My radiator boxing also blocks the portion at the bottom between the bumper cover and the bottom of the radiator support. If I understand you correctly, you remove that when doing high speed runs? Between the splitter, bottom opening, and the vented hood, do you have an opinion as to the relative contributions of the three to high speed stability?

As an aside, I'm willing to do some cheap experimentation next month during practice runs at BBORR, so keep the ideas flowing.

 

[racebronco2]

I found out that the splitter will lower your top speed from point to point. In a half mile run it lowers the speed by about 5-8 mph. There is no instability up to 150mph, i haven't been any higher then that on track. If i were you i would use the mach 1 chin spoiler, that what i use on the high speed runs, that way it will provide some downforce and added airflow into the bumper opening and with the bottom open the excessive pressure will just exit the opening between the bumper cover and radiator support. You might want to experiment with different size opening to determine the best size for cooling and high speed stability.