Can the mph that raises the rear spoiler be changed?

[KRAM36]

Originally Posted by Topless

And if the spoiler created more drag, why did the car with a spoiler outperform the car with no spoiler in straight line testing??
1st- Car equipped with wing
2nd- Car equipped with spoiler
3rd- Car with no spoiler or aero device.

Hmmmm... Still so much to learn Grasshopper.

Sorry, but that guy doesn't know what he is talking about in the straight line test. The car with no spoiler and identical to the cars with a spoiler would win the straight line race.

Read the comments on the video. "The main argument though was that spoilers make you faster in a straight line, which is false."

[Topless]

Originally Posted by KRAM36

"The main argument though was that spoilers make you faster in a straight line, which is false."

Got any wind tunnel data to support that? Thought not.

[KRAM36]

Originally Posted by Topless

Got any wind tunnel data to support that? Thought not.

Do you?

You have to be kidding me if you think spoilers make a car faster in a straight line.

They create drag, they press the car to the ground which takes more power to move the car.

[Smallblock454]

Originally Posted by KRAM36

Do you?

You have to be kidding me if you think spoilers make a car faster in a straight line.

They create drag, they press the car to the ground which takes more power to move the car.

Yes and no.

An ideal spoiler should generate downforce. At the same time it should reduce the drag coefficient by optimizing the airstream. So if it is designed well it should not make the car slower but generate downforce.

Other aspects: front and a rear axle have in general different down- and upforces. So you have to optimize the whole body system aerodynamicly.

But if you can drive only 55, i think there is no need for big aerodynamic experiments.

Regards from
279 - that's the number i get in my instrument cluster on the flat Autobahn.

[Topless]

Originally Posted by KRAM36

You have to be kidding me if you think spoilers make a car faster in a straight line.

They create drag, they press the car to the ground which takes more power to move the car.

Quite the opposite actually. Instead of creating downforce our spoiler "spoils" lift and often but not always reduces Cd. Airflow lifting several hundred lbs on the tail of the car causes a low pressure zone, turbulence and drag. Solve that and you improve stability, fuel efficiency, and straight line speed. Porsche aerodynamicists understand this, tested and confirmed it. Some grasshoppers not so much.

The modern 991 Turbo takes it a step further with active front and rear spoilers but the goal is the same. Stability, fuel efficiency and straight line speed with the lowest possible Cd. https://www.youtube.com/watch?v=A9FluxQn0ZE

[KRAM36]

Originally Posted by Topless

Quite the opposite actually. Instead of creating downforce our spoiler "spoils" lift and often but not always reduces Cd. Airflow lifting several hundred lbs on the tail of the car causes a low pressure zone, turbulence and drag. Solve that and you improve stability, fuel efficiency, and straight line speed. Porsche aerodynamicists understand this, tested and confirmed it. Some grasshoppers not so much.

The modern 991 Turbo takes it a step further with active front and rear spoilers but the goal is the same. Stability, fuel efficiency and straight line speed with the lowest possible Cd. https://www.youtube.com/watch?v=A9FluxQn0ZE

First of all, drop the name calling.

Secondly, why doesn't Porsche just leave the spoiler in the up position all the time on our Boxster? If it increases fuel economy, aids in less drag and they could reduce cost and weight to the car by leaving the spoiler motor out.

The answer is Porsche knows it does not aid in fuel consumption nor reduce drag on the car. It's only deployed at the speed Porsche feels the car needs the added downforce.

[particlewave]

Wow...what happened here?

I really don't want to end up having someone mad at me, but one person is absolutely 100% correct and the other is absolutely wrong.
Let's just say that Porsche did their homework and a spoiler is called so for a reason.
Aerodynamics affect a car differently at different speeds, hence the reason for a speed activated spoiler

[woodsman]

Originally Posted by Smallblock454

Regards from
279 - that's the number i get in my instrument cluster on the flat Autobahn.

Wow I can tell you ain't been to Kansas(just east of Kansas City) I70 interstate; one of the loneliest, flattest and straightest pieces of pavement in the world. As for the autobahn, enjoy the small 'unlimited' stretch while you can- I hear it's getting crowded...

[KRAM36]

Originally Posted by woodsman

Wow I can tell you ain't been to Kansas(just east of Kansas City) I70 interstate; one of the loneliest, flattest and straightest pieces of pavement in the world. As for the autobahn, enjoy the small 'unlimited' stretch while you can- I hear it's getting crowded...

Where is this stretch of highway? I live in KC, but I don't think I've been on that part of I-70. Now I want too find it. What about police on this stretch?


.

[KRAM36]

Topless, apparently my thinking is incorrect. You are correct in this on the way our spoilers works.

I'll no longer worry about the spoiler causing a drag on the car and lowering the mpg.

I am grasshopper. Thanks for the lesson learned.

[Topless]

No worries mate! If everyone just always agreed with each other this forum would get pretty boring.

[KRAM36]

Seriously though, thanks for staying on this and the knowledge I gained from your persistence. Very glad you didn't give up on it.

[woodsman]

Originally Posted by KRAM36

Where is this stretch of highway? I live in KC, but I don't think I've been on that part of I-70. Now I want too find it. What about police on this stretch?


.

Head to Denver. At night. What I said is relative to the roads everywhere else in North America. I90 through Nebraska, North Dakota is similar. Saskatchewan is even better. I40 is loaded with cops- Arizona, New Mexico-they need the revenue, I've even seen false construction areas there.

[KRAM36]

Originally Posted by woodsman

Head to Denver. At night. What I said is relative to the roads everywhere else in North America. I90 through Nebraska, North Dakota is similar. Saskatchewan is even better. I40 is loaded with cops- Arizona, New Mexico-they need the revenue, I've even seen false construction areas there.

Ah, so this is on the west side of Kansas?

[particlewave]

I took the I-80 route to Denver last month. That's a lot of flat nothing for a long time.
It makes I-70 look like gold.

On the plus side, I think I saw all of 2 officers both ways (not that I speed ).

[KRAM36]

Originally Posted by particlewave

I took the I-80 route to Denver last month. That's a lot of flat nothing for a long time.
It makes I-70 look like gold.

On the plus side, I think I saw all of 2 officers both ways (not that I speed ).

You know how KC is, there are a lot of straight stretches, but they are not flat, so you can't chance it as a cop could be right over the hill.

I have one spot I let her go for all she can get. Going north by the downtown air port, 2 lanes one direction with concrete barriers on both sides. Check for police sitting in the grass at the on ramp right before the straightaway, no traffic in front of me and I let her rip. I get to up to 132 in that little stretch. Can't wait to see what I can get with the new intake system. Car is pulling so much harder now.

[particlewave]

As soon as I saw "downtown airport" I knew the spot
The one running parallel to the railroad tracks, correct? Those barriers make it really intense!
That's the route I take to and from the museums/Union Station.

[steved0x]

There is a new curvy road here in my town that cuts through some gentle hills/woods between two main roads that has guard rails almost the whole way... Not as good as a one-way with barriers but as good as we get here.... my spoiler is definitely raised the whole way (spoiler tie-in )

[KRAM36]

Originally Posted by particlewave

As soon as I saw "downtown airport" I knew the spot
The one running parallel to the railroad tracks, correct? Those barriers make it really intense!
That's the route I take to and from the museums/Union Station.

Exactly the spot lol.

Originally Posted by steved0x

There is a new curvy road here in my town that cuts through some gentle hills/woods between two main roads that has guard rails almost the whole way... Not as good as a one-way with barriers but as good as we get here.... my spoiler is definitely raised the whole way (spoiler tie-in )

That sounds like fun! About like my favorite twisties I run through here, but no guardrails.

[JayG]

Originally Posted by KRAM36

I want the spoiler to come up, but I don't think it's needed at 75 mph.

Why am I concerned with drag? Because this is my DD and that causes fuel economy to go down and drag isn't the only thing, I think it looks tacky when deployed for no reason.

I rarely hit 85 mph, but 75 mph is easy when the highway speed is 70 mph and you need to get around another car. So here is this spoiler up for no reason and doesn't come back down until 50 mph.

I realize you have now seen the light and understand that the spoiler goes up and down at a specific speed for a reason and does not lower mpg as that was your concern. So if getting better mpg is your concearn, why are you looking at increasing HP with a bunch of engine mods in another thread? That will surely decrease MPG. The easiest way to increase MPG is to slow down a bit, especially if you are going 70+