Bug Deflector Air-Flow

[tysonK]

I wanted to interupt more damage to the front of my hood so I was thinking about purchasing a front bug deflector.

It says for non-turbo application, on the subaru instructions. I guess it shunts to much air above the hood scoop?

Clear bra is the only real option?

[Nick Koan]

Yeah, that and even the leather bra redirects too much air. I think clear bra is your only option.

[JC]

Originally Posted by nKoan

even the leather bra redirects too much air.

They make a WRX specific one.

[sperry]

Originally Posted by JC

They make a WRX specific one.

Actually, I think they used to sell the RS one for the WRX, then changed their mind and labeled it as "RS/TS Only"... unless there's a new one out for the bug-eyes.

Which reminds me, I've got a bug-eye bra purchased from back when they were considered "okay" for the WRX. I'll sell it to ya Tyson if you're willing to "risk" the airflow issue... which I don't think is a hoodscoop flow issue, I believe it's a snorkus flow issue under the hood.

[tysonK]

Originally Posted by sperry

Actually, I think they used to sell the RS one for the WRX, then changed their mind and labeled it as "RS/TS Only"... unless there's a new one out for the bug-eyes.

Which reminds me, I've got a bug-eye bra purchased from back when they were considered "okay" for the WRX. I'll sell it to ya Tyson if you're willing to "risk" the airflow issue... which I don't think is a hoodscoop flow issue, I believe it's a snorkus flow issue under the hood.

It might look armour on my black car. I can give it a try.

[tysonK]

this guys sports one.

[Nick Koan]

True, but I've seen a lot of people do stupid things with their WRXs.

Nice highway BTW.

[cody]

What you need is a shield that doubles as a vortex generator to focus more air into the scoop. Now that'd be pimp.

[sperry]

Originally Posted by cody

What you need is a shield that doubles as a vortex generator to focus more air into the scoop. Now that'd be pimp.

So, basically you want a deflector that actually *increases* the number of bugs that hit the car. Interesting!

[cody]

So you'd have a few more bugs hitting the scoop and the windshield...I'm not scared.

[sperry]

Originally Posted by cody

So you'd have a few more bugs hitting the scoop and the windshield...I'm not scared.

It's not much of a "deflector" if it actually increases debris into the car, which is exactly what Tyson's trying to prevent.

Originally Posted by tysonK

I wanted to interupt more damage to the front of my hood so I was thinking about purchasing a front bug deflector.

If you really want more air into the hood scoop, just get a bigger hood scoop.

[cody]

How is a piece of material on the hood going to increase debris reaching the car? :confused: The vortex generator/hood protector would point more air into the hood scoop and protect the hood from damage. A piece of debris that reached the hood wouldn't be any more dangerous or common. It's not going to suck junk off the road and throw it at the car.

[JC]

Originally Posted by sperry

Actually, I think they used to sell the RS one for the WRX, then changed their mind and labeled it as "RS/TS Only"... unless there's a new one out for the bug-eyes.

Which reminds me, I've got a bug-eye bra purchased from back when they were considered "okay" for the WRX. I'll sell it to ya Tyson if you're willing to "risk" the airflow issue... which I don't think is a hoodscoop flow issue, I believe it's a snorkus flow issue under the hood.

Your right, I was thinking of the deflector.

https://www.subarugenuineparts.com/p...roducts_id=650

[sperry]

Originally Posted by cody

How is a piece of material on the hood going to increase debris reaching the car? :confused: The vortex generator/hood protector would point more air into the hood scoop and protect the hood from damage. A piece of debris that reached the hood wouldn't be any more dangerous or common. It's not going to suck junk off the road and throw it at the car.

I'm not a aerodynamicist so I'll defer to JC on the details, but the way a bug deflector works is by spoiling air at the leading edge of the hood so bugs are deflected by the airflow up and away from the hood/windshield.

If you're attempting to use the same principle to direct more air at the hoodscoop, you're going to also be directing anything in that air at the scoop, and therefore the windshield behind it. I.e. bugs and the like that would normally by pushed aside by the shape of the hood are now being directed at the car.

Not only would such a "vortex generator" probably work worse than a properly designed hood scoop, it would probably concentrate bugs into the scoop, and on the windshield, not to mention the possible effects during wet conditions... personally I'd rather have as close to laminar flow over my windshield, rather than a swirling mess of rain/snow.

...but again, I've got no background in aerodynamics aside from a general understanding, so I'll differ to the people that know more about these things like JC and AtomicLabMonkey.

[JC]

If you want more airlfow into your hood scoop, buy a bigger one. If you want less bugs on your car, get a daily driver.

Scott got it basically right, though I have no idea why the word vortex generator is being thrown around. On a related note, I have no idea about the new deflectors but the old style ones (straight vertical) would noticably decrease mileage or so I've been told by people who had them. I'm sure the new ones lessen the effect but you are still adding drag to your car for the sake of a cleaner windshield.

[tysonK]

Originally Posted by JC

If you want more airlfow into your hood scoop, buy a bigger one. If you want less bugs on your car, get a daily driver.

Scott got it basically right, though I have no idea why the word vortex generator is being thrown around. On a related note, I have no idea about the new deflectors but the old style ones (straight vertical) would noticably decrease mileage or so I've been told by people who had them. I'm sure the new ones lessen the effect but you are still adding drag to your car for the sake of a cleaner windshield.

Well the paramount reason I wanted the get the deflector was to act as a leading edge shield for my hood. I guess I could just get a little clear bra strip. I'm worried that with another winter or so I might be having to repaint it soon or get a new hood, it really bothers me. My hood has the most chips right where the bug deflector would be.

I don't care about the bugs hitting my windshield I wash it everytime I get home.

[cody]

Originally Posted by sperry

I'm not a aerodynamicist so I'll defer to JC on the details, but the way a bug deflector works is by spoiling air at the leading edge of the hood so bugs are deflected by the airflow up and away from the hood/windshield.

If you're attempting to use the same principle to direct more air at the hoodscoop, you're going to also be directing anything in that air at the scoop, and therefore the windshield behind it. I.e. bugs and the like that would normally by pushed aside by the shape of the hood are now being directed at the car.

Not only would such a "vortex generator" probably work worse than a properly designed hood scoop, it would probably concentrate bugs into the scoop, and on the windshield, not to mention the possible effects during wet conditions... personally I'd rather have as close to laminar flow over my windshield, rather than a swirling mess of rain/snow.

...but again, I've got no background in aerodynamics aside from a general understanding, so I'll differ to the people that know more about these things like JC and AtomicLabMonkey.

I agree with some of what your saying, but keep in mind that the "bug deflector" wouldn't work on a WRX retaing the TMIC. I'm just saying if you have a rock guard on the front of your hoood to protect it from chips, why not design it so that it points more or the same amount of air into the scoop instead of hampering the flow. Then you can have your cake and eat it too.

Sure, more bugs are going to hit your car than if you were running a true bug deflector that pitches air and debris over your car, but that's not an option on TMIC car. The amount of bugs/debris that hit your car with the vortex generator hood protector thingy would be similar to without, I'm guessing.

JC, I got the word "vortex generator" because the EVO MR has one on the rear edge of the roof to put more force on the rear wing.

Maybe it is a dumb idea. I mean if you've got a couple of aerodynamicists on your side, I'll just shut up.

[Nick Koan]

I think JC means you could direct air at the hoodscoop without generating any vorticies IF that is what you really wanted to do.

But, again, if rock chips are all you are trying to prevent, then a clearbra/rockblocker type film would be the best answer.

[cody]

Yah that's what I have, I'm just playing devil's advocate.

[JC]

Originally Posted by cody

I agree with some of what your saying, but keep in mind that the "bug deflector" wouldn't work on a WRX retaing the TMIC. I'm just saying if you have a rock guard on the front of your hoood to protect it from chips, why not design it so that it points more or the same amount of air into the scoop instead of hampering the flow. Then you can have your cake and eat it too.

Sure, more bugs are going to hit your car than if you were running a true bug deflector that pitches air and debris over your car, but that's not an option on TMIC car. The amount of bugs/debris that hit your car with the vortex generator hood protector thingy would be similar to without, I'm guessing.

JC, I got the word "vortex generator" because the EVO MR has one on the rear edge of the roof to put more force on the rear wing.

Maybe it is a dumb idea. I mean if you've got a couple of aerodynamicists on your side, I'll just shut up.

Because it's no longer a bug deflector is the simple answer. The point of a bug deflector is to deflect bugs over your windshield. It you changed it that it directed them AT your windshield it would no longer serve it's primary purpose. I'm not sure how you'd go about directing air at the scoop anyway but I can assure you it's much more effective to just get a larger scoop. I assumed that's where you got vortex generator from but it doesn't relate to bug deflectors.

JC

[cody]

Again, forget about deflecting bugs on a car with a TMIC. The original poster wants to protect his hood. My idea would theoretically serve that purpose without hampering flow to the hood scoop.

[JC]

Originally Posted by cody

Again, forget about deflecting bugs on a car with a TMIC. The original poster wants to protect his hood. My idea would theoretically serve that purpose without hampering flow to the hood scoop.

The simple answer is it's not practical.

[cody]

You mean because of the necessary R&D?

[Nick Koan]

Originally Posted by cody

You mean because of the necessary R&D?

The compromises. There are too many compromises to make the whole idea not practical.

[sperry]

Originally Posted by nKoan

The compromises. There are too many compromises to make the whole idea not practical.

Plus, clearbra's already been invented.