Hood-less is better??
 

I removed the hood from Julie this weekend, so I can cut holes and install vents. Due to an argument I had with an angle grinder, the hood is currently removed pending some trimming on the holes, and I am continuing my daily commute hood-less. Looks cool, and lets you see just how much that motor moves, too......

Keeping in mind that the cd of a cinderblock is actually better than that of my Jeep, I pose the following question: Removing the hood would make for a messy area of turbulence to form over the engine bay. However, it seems that the Jeep runs fine down the highway (no buffeting), and my coasting times seem to be longer. I actually had to hit the brakes at the stop light today.....she was coasting better than usual! Any ideas about why this happened???

things i can think of are:

better escape route for air comming in trough the grill
less high pressure in front of the windshield
thus overall better airflow over the vehicle...

or it might simply be weight reduction... a hood is a rather big piece of metal...

I thought of that...but I would have to hang a light inside so I could see it....and then move the steering wheel to the roof so I could see over it :D

I'm actually using a set of vents from a 1984 Chrysler New Yorker, the one with the 2.4L turbo. It's going to look pretty good, if these grinder-burns heal up enough to let me work on it again.....

I'll get some photos posted when she's done...maybe even a tech. writeup for those interested.

old school racers used to jack up the back of the hood for performance. you can see the engine from the windsheild. I guess home made cowl induction or just a quicker way for heat to escape.

But rumor has it that if you tuft test a hood like that, the yarn will get sucked into the engine compartment, which would indicate flow opposite of what we are supposing for RaccoonJoe...

This is why people do cowl induction on their cars....the yarn will actually get sucked into the engine bay. Something about a low pressure zone where the hood meets the windshield....

Ya, a high pressure zone, I think, helping force more air into the engine.

I think my bs meter just hit the peg.

How about running some long bits of yarn by the grille and see where air is going? I'd say tape it around the fan shroud, off the intake box, the valve cover and anything you might have on the passenger side fender

Sorry, we drifted off and were talking about old TransAms and such, not FE stuff...

But, a good point raised--there's a high pressure point at the base of the windshield. It's not the place to vent the engine compartment.

Either the Granatelli's or Smokey Yunick, can't remember which, made a clear plexi hood for one of their stock cars and tufted the engine compartment. Claimed to have seen measureable improvements by moving components around under the hood.

Heh-heh. I'm told I can drift off and bs with the best (worst?) of them.
Anyway, turned out to be an interesting discussion, and is actually aero-oriented anyway.

Sounds like a Yunick to me. He was a very innovative person, even went so far as to install a windmill on a car to run the generator, and even hand built an exact 7/8 replica of a 1967 Chevelle to run at the races. Nobody noticed it until he made the mistake of parking it beside a factory 67. Another trick was cheating on the fuel load, he used a 2 inch diameter fuel line to carry fuel from the gas tank to the engine, giving him another 2-3 gallons of capacity. This was discovered when the tech inspectors removed the fuel tank for measuring, and someone got into the car and drove a couple of laps with no fuel tank in the car. Smokey Yunick is probably responsible for about 90 percent of the NASCAR codes where measurements are concerned.

The windmill driven generator idea running an alternator might work for fuel economy, should be enough to keep the battery topped up at highway speeds without affecting fuel economy. There would be more than enough air to drive the blades if you mounted it so part of the blade extended down into the undercar airflow, and this should have zero effect on fuel economy since that air has already disturbed the motion of the vehicle.