Why pop up headlights ?, Philosophic question ... Options

[johannes]

As the 914 was supposed to be cheaper than the 911 why did they go the pop up way ?
I was told, the 914 had to feature popup headlights because the US regulation mandated a minimum height for the headlights ...
I made some searches on the Internet and found this excellent wiki... http://en.wikipedia.org/wiki/Headlamp ... They tell a lot about the 7' round, shaped, sealed lamps ... but there is no information about height.
Can you light me ? (IMG:style_emoticons/default/biggrin.gif)

[Eric_Shea]

Man... now that I'm home and have the time to read through this stuff, it's simply amazing. GREAT job Chris (if you're out there)!!

Back on target, if the mirrors coming off can give you a little over 1/2 hp, imagine what a couple of pop up lights can do smack dab in the middle of the air stream. I would imagine that helps answer the original question why pop up headlights. I would say it's a bit of a design feature to clean out the lines and it really helps in the CD arena.

I'm amazed at the dye tests with the top and windows up. The computer models prove it out as well. The 914 does DAMN good for a late 60's design. LOOK WHAT HAPPENS TO THE DOWN FORCE WITH THE WINDOWS AND TOP OFF!!! (computer models and the dye test) Wow! That's more like what I see with a standard 911 shape, spoiled air right over the rear wheels, hence the need for a tail on a 911 to force the spoiled air behind the vehicle.

- Stock has 28lbs. of down force (Newton value converted)
- Top off and windows down has -6.67lbs. (better know as lift as it spoils the rear air-flow over the decklid)

The best you could probably get with a stripped down (no windshield) race version might be around 50lbs. of additional downforce so we're not talking about great advantages either way. I'm suprised at how well a stock car works.

The main thing I'm getting from this is; the worst thing you could do is add front and rear spoilers (well... that and take your top off). Look at example #13; the delta on the drag is 64.2093 newton, the lift is now 5.26lbs. greater and the loss of hp is 2.084. This basically proves that "every" aerodynamic gadget we have available at our disposal does more harm than good.

Big wings simply add more drag, more lift and less hp. I'm happy with my stock GT look I guess. (IMG:style_emoticons/default/wink.gif)

[ClayPerrine]

The main thing I'm getting from this is; the worst thing you could do is add front and rear spoilers (well... that and take your top off). Look at example #13; the delta on the drag is 64.2093 newton, the lift is now 5.26lbs. greater and the loss of hp is 2.084. This basically proves that "every" aerodynamic gadget we have available at our disposal does more harm than good.

Big wings simply add more drag, more lift and less hp. I'm happy with my stock GT look I guess. (IMG:style_emoticons/default/wink.gif)

Actually adding a front air dam (spoiler) will help the stability of a 914. While slicker and faster without it, the front of a 914 will lift at high speed without one. This makes the car unstable. So you won't be able to drive as fast.

The same thing was discovered with the 917 when John Weir took over the Gulf Porsche team. Porsche wanted to concentrate on the long tail, but the short tail was way more stable after adding a few spoilers, and was able to make better lap times because it didn't have to slow down as far for the turns.

[r_towle]

The main thing I'm getting from this is; the worst thing you could do is add front and rear spoilers (well... that and take your top off). Look at example #13; the delta on the drag is 64.2093 newton, the lift is now 5.26lbs. greater and the loss of hp is 2.084. This basically proves that "every" aerodynamic gadget we have available at our disposal does more harm than good.

Big wings simply add more drag, more lift and less hp. I'm happy with my stock GT look I guess. (IMG:style_emoticons/default/wink.gif)

Actually adding a front air dam (spoiler) will help the stability of a 914. While slicker and faster without it, the front of a 914 will lift at high speed without one. This makes the car unstable. So you won't be able to drive as fast.

The same thing was discovered with the 917 when John Weir took over the Gulf Porsche team. Porsche wanted to concentrate on the long tail, but the short tail was way more stable after adding a few spoilers, and was able to make better lap times because it didn't have to slow down as far for the turns.

Do spoilers really help in an autox?
If we accept that 65 mph is the fastest you can go, does aerodynamics really come into play on the front end?

Rich

[6freak]

The main thing I'm getting from this is; the worst thing you could do is add front and rear spoilers (well... that and take your top off). Look at example #13; the delta on the drag is 64.2093 newton, the lift is now 5.26lbs. greater and the loss of hp is 2.084. This basically proves that "every" aerodynamic gadget we have available at our disposal does more harm than good.

Big wings simply add more drag, more lift and less hp. I'm happy with my stock GT look I guess. (IMG:style_emoticons/default/wink.gif)

Actually adding a front air dam (spoiler) will help the stability of a 914. While slicker and faster without it, the front of a 914 will lift at high speed without one. This makes the car unstable. So you won't be able to drive as fast.

The same thing was discovered with the 917 when John Weir took over the Gulf Porsche team. Porsche wanted to concentrate on the long tail, but the short tail was way more stable after adding a few spoilers, and was able to make better lap times because it didn't have to slow down as far for the turns.

Do spoilers really help in an autox?
If we accept that 65 mph is the fastest you can go, does aerodynamics really come into play on the front end?

Rich

Plan and simple ...No It just cost horse power, witch cost time, because you have more air to push out of your way .....But they look cool