Front bumper shape

[Sven7]

Originally Posted by Cd

Under ? Don't you mean over ?

He means that when the Point of Stagnation is halfway from the top and bottom, half of the air will go up and half will go under. The pressure of the air going under will want to push the car up into the air, creating lift (while a more or less equal force on the top pushes the car down). Lowering the PoS will let more air over the top than under the bottom, skewing the air pressure to create more downforce than lift.



BTW, how does one go about making a strong stable, durable bullet nose? Perhaps I'll have to study the Aero Civic thread.

[Gone2]

I do know the answer to that. Styrofoam and fiberglass mat. Some people don't like to work with it, but it is relatively easy and very durable. You could also use a base layer of household screen and then fiberglass over it. It makes the fiberglass more durable.

[Cd]

Originally Posted by Sven7

He means that when the Point of Stagnation is halfway from the top and bottom, half of the air will go up and half will go under. The pressure of the air going under will want to push the car up into the air, creating lift (while a more or less equal force on the top pushes the car down). Lowering the PoS will let more air over the top than under the bottom, skewing the air pressure to create more downforce than lift.



BTW, how does one go about making a strong stable, durable bullet nose? Perhaps I'll have to study the Aero Civic thread.

I assumed that by " bullet nose " we were talking a half bullet nose, such as a Corvette, a Firebird, a Saturn SC coupe, or the car on page one.



Cars with bullet noses such as the Avion will of course have more of the air flowing under the car.

[Frank Lee]

Originally Posted by winkosmosis

I'd like to see a picture of a front end without attached flow... Following your logic, you could take off the bumper and the whole front fascia, flow will still be attached, and drag won't change.

The problem with the silver bullet nose is that it directs so much air down below the car.

There's a bit missing off the front of the Coupe, and yet this is the one (of 5 Tempos) that gets the best fe. I conclude the flow hasn't been compromised all that much, if at all.

[Sven7]

George I just saw the thing about the yachts-really interesting!

And for whatever reason this quote seemed important:

A yacht is not defined by the vessel but by the care and love of her owner

Originally Posted by Cd

I assumed that by " bullet nose " we were talking a half bullet nose, such as a Corvette, a Firebird, a Saturn SC coupe, or the car on page one.

Cars with bullet noses such as the Avion will of course have more of the air flowing under the car.

No worries!

Originally Posted by Frank Lee

There's a bit missing off the front of the Coupe, and yet this is the one (of 5 Tempos) that gets the best fe. I conclude the flow hasn't been compromised all that much, if at all.

You mean the sealed beam lights and those gaping holes don't make that much of a difference? (Is that your 27mpg Tempo?)

[Cd]

Originally Posted by Frank Lee

There's a bit missing off the front of the Coupe, and yet this is the one (of 5 Tempos) that gets the best fe. I conclude the flow hasn't been compromised all that much, if at all.

Are you being sarcastic Frank ?

[Frank Lee]

No sarcasm, and that is the 35mpg Tempo (gaslog not on EM).

Maybe the radiator block is so good it more than cancels out the bad headlight areas/fender scoops?

[aerohead]

Originally Posted by Frank Lee

There's a bit missing off the front of the Coupe, and yet this is the one (of 5 Tempos) that gets the best fe. I conclude the flow hasn't been compromised all that much, if at all.

It looks like the only issue would be the tiny leading edge on the fender sides where the turn signals were removed.The fenders have nice penetration curvature rear of that area,so those areas would still be in 'attack',with immediate re-attachment and little drag.
Hood edge and bumper radii look plenty smooth.
Makes sense to me Frank!

[Frank Lee]

It is all good but the open areas around the headlights are not closed off; they lead to the inner fenders and after a labyrinth path, the engine compartment. Perhaps what I have is about the same flow through the engine compartment even with that nice big radiator block; or maybe the flow through all that nonsense is stifled such that there isn't really much flow entering those areas in the first place. At any rate, fe and probably top speed (not accurately tested) seem to not be negatively affected.

[Cd]

It would certainly be interesting to see a tuft test along the sides of those fenders Frank.
Thanks for posting the example.
I can certainly see what Aerohead was referring to about immediate reattachment along the sides.
As far as the little tabs that hold the side signal lights on, they might even function the same way that the creased sides do on the front end of the Prius.

Its hard to tell without tufting it though.

( I hope you do get around to fixing that front end ! Good luck passing inspection without the turn signal lights )