69 coupe spoiler advice

The rear spoiler will push the rear down thus pushing the front up. A properly adjusted rear spoilers will work at about 100 mph. (Ask me how I know!) The front spoiler is the one that keeps the the front down by spoiling the airflow under the car that causes the entire car to act like a wing. A stock mach 1 front spoiler will make a difference on your car. StuK

A wing causes the air to move faster over one side of it than the other, like a car body. The air moving faster over the top of the wing, or car body, lowers the pressure above it creating lift beacuse the presssure below the wing does not change. It's the normal pressure below the wing, or car body, that allows it to be lifted by the lower pressure created above it. A rear spoiler is there to 'spoil' the lift, or low pressure area created by the airflow over the body, it does not create down force. The splitter on the front lowers the amount of air going under the front of the car which lowers the pressure under the car. Less pressure under the car means less lift when the pressure is lowered above the car.

"WraithCobra" wrote

You better tell all the top fuel guys and the vintage SR-2 racers then. Depending on the angle of the rear spoiler (extreme in most instances), downforce might or might not be created.

Then you are using the term "spoiler" incorrectly. A "spoiler" spoils lift, it does not create down force. If the apparatus on the rear of the body creates down force, like an upside down wing, then it is called a "wing".

Mike,

Cool, so how did you come to know so much about aerodynamics?

My Father was a licensed pilot and had a Cessna Skyhawk when I was in my teens. I also spent 10 years in the USAF, should have gotten my private pilot license but found other uses for the $$. I've read things here and there on the subject of aerodynamics and know the basics of how things work, but I don't have an in depth knowlede on the subject.

Coulda fooled me. Excellent post.

So, sounds like having both front and rear "spoilers" would help. Except for the guy that said a stock mach 1 spoiler would not work on a coupe.

Thanks,

"Jack Napier" wrote

Why wouldn't it? You just make a few small holes in the decklid and bolt it on. You just have to be REALLY careful.

's a pic from Mustang and Fords showing what le mans stripes and a =front spoiler look like on a '69 coupe.

When you say spoiler are you talking about the FRONT or the back (wing)? The wing will work at about 100 mph. Again, the front spoiler will stop the lift you get on the old Mustangs at around 80/90. My '71 Cyclone Spoiler use to hunker down closer to the road at speed. At 115 mph I actually started scraping my mufflers on the road. StuK

with the decklid spoiler i was worried about getting stuck with one that doesnt let you adjust the angle. do the repros adjust? also with the front spoiler ive seen them listed as, "the bolt on type" what other types are there? whats the best to get and do they require modifications to the body or valance to install??

"Jack Napier" wrote

I was thinking the same thing. Do they have Velcro?? I can see the Ricer's pulling off their spoilers to stash them in the trunk when they go into the mall. Velcro! LMAO!!!

The proper decklid spoilers used on '69/'70 Mustangs are adjustable. The '69 BOSS's had plastic ones and they tended to droop in the middle on hot days so Ford made the '70's out of fibreglass. They were actually quite heavy and required a small prop rod to stop the trunk from closing. The same one was used on the '70/'71 Cyclone Spoilers and the Cougar Eliminators. ( Mercury painted them body colour) The '71 to '73 Mustangs used the same wing part but had shorter legs to account for the larger ( higher) fastback. As for the stock front spoilers they screw or bolt on to the valance and are molded to the shape of the valance. I added some small metal brackets near the middle on my '70 mach 1 as I have seen them fold under at high speed ( they are ABS plastic) HTH StuK

for example, the ones sold by

are ABS plastic, the rear has a steel rod through it to keep it straight and they sell all the mounting hardware. the front one is bolt on type and dont know if they have mounting hardware and it plastic. they also carry all the shelby scoops. and a mach 1 hood scoop which im also thinking about.

i think im gonna go for it with the side scoops, i plan on keeping this car quite a long time and why not go all the way and do something special with it.

days so Ford

a small prop

part but had

front spoilers

fold under

The wing will

At 115 mph I

Sounds like a plan. Personally I like the Mercury Eliminator scoop. It looks like a BOSS

429 scoop but has more "civilized" dimensions. It was also used on Comet GT's in the early '70's. StuK

Ford

prop

had

spoilers

added

under

will

mph I