Hood vents/mod ideas?

[quote]New 2 Z wrote:

Originally posted by TurboDreams

CdA (drag coefficient x area; lower is better)

Honda Insight - 5.10
Lamborghini Diablo - 6.17
Bugatti Veyron - 8.02

Believe it. Honda has done A LOT of testing in the creation of the insight. They are designed for aerodynamics.

to say the drag coefficient of a vehicle means nothing without knowing the frontal area is like saying a bullet with no point wouldn't be able to penetrate an object regardless of its speed.

Cda would be a better means to calculate acceleration, not necessarily stability at high speed. the Cda would be an argument better suited towards how much resistance two similarily designed objects would have to overcome while taking off at the same time, and weighing exactly the same- but with one object having a larger frontal area or being overall larger, while the Cd remains constant.

Cd in itself means much, and does not always require the interpolation of frontal area in order to measure its benefits.

CD in itself means nothing. It is only one factor which remains irrelevant if the other factor is an unknown variable.

It's like saying any vehicle with 1000hp is faster than any 300hp vehicle. Both of which you have no idea what they are. For the sake of comparison lets say it's a tank vs a Z31. Now your Z31 may be grossly underpowered but the tank probably weighs at least 10x+ more, has ridiculous drivetrain loss and tops out somewhere between 40-65mph. The only way the tank is going to win a race is if it's through a brick wall, regardless of your idiotic generalization that horsepower = speed. No matter what you need to know the other variable.

Are you an engineer turboDREAMS?

Are you posting from a mental institution sprtCRAZY17?

Ok, i am confused…

If CdA is the Cd(coefficient of drag) x the surface area, how is the Z32 better than the Z31. Not only is its Cd higher than the Z31, but have you seen the front of that thing…its has to be bigger than the Z31. Where do they take their measurements. And on top of that the S13 does really well, and those cars are VERY similar size wise to the Z31.

I take that as a no. I thought so

With all due respect, if you are saying that I stated that horsepower = speed, then you didn't read my post correctly and I think you should look it over again… There are many other factors/formulas in which you can use Cd.

your tank vs. z31 post has absolutely nothing to do with what I was saying. Please re-read what I said carefully before assuming things about weight and power.

If you think what I said is flawed, please tell me in reference to my own post how it is flawed, not in reference to something I did not mention. But before you do, ask yourself something… If using frontal area and Cd is NOT used to best calculate the amount of resistance an object has to overcome in order to accelerate to a certain speed in a certain amount of time moving FORWARD, then why not use the side area, or the rear area? The boundary layer needs to stick to these parts as long as possible as well, as it grossly affects the drag on a vehicle… and last I remember, acceleration tests are done moving forward in a straight line.

So again… what does frontal area have to do with the overall stability of the car at speed when there is much more to something than it's frontal size? What if the side of the car had big bulging air vents; like porsche, or ferrari uses? Does that get factored into the frontal area? because if the car gets larger as it gets longer, then where does the "front" end?

Again, frontal area x cd is better used to calculate an objects relative resistance to acceleration in comparison to objects with a smaller frontal area with a close cd. It's NOT used to calculate stability at speed.


I think StreetFighter's point here is that at speed, the z31 is pretty damn good at staying planted. If he were going 200mph in a Z31 that has been fabricated to be twice the size… It's going to be just as stable. Why? Because Cd is constant, and provided all else is doubled up to exacting specifications, it's going to remain just as stable at double size as it is at 1:1 size due to the coefficient of drag being the same, provided everything else is doubled up.

Careless nailed it. And as SOON as Streetfighter posted anything is when this topic should have been over with. His Z31 has very few aero-modifications, and I believe the vents he has are to cycle heat out. The man goes faster than EITHER of the bench racers in this thread (you know who you are) will ever see in their lifetimes outside of an aircraft.


/thread for Careless and Streetfighter.

i agree

Here are a few more detailed pics of the 280zx vent installed and the vents I started making in my fenders this weekend.

forgive me for my ignorance but whats the point of the fender vent?

Evacuate air from the fender? (in theory at least)

Pull/evacuate air from the fender. The constant pull of air will also cool the front vented rotors pretty well. Excellent work, KhyronZ. I love how you have no qualms about cutting up and welding your car. Mad props.

Thanks, thats what intended them for(air extraction from the fenders). Can't decide if I want to put in the other 280zx vent on the other side or not, what do you all think? Gonna do a big drop vent in the middle of the hood whenever I get an E-fan setup.