Hood lift at high speeds

[Basti]

Dunno whether this comes up much butI've heard of this issue several times already:

Upon reaching more "interesting" speeds, the hood starts to lift slightly. Well, it's still hinged safely in place but when it happened to me on a particularily even strip of highway I got shaking from that interference and driving above that speed neither felt reassuring or safe anymore.
I guess it started at about 180km/h.

Now I know that I'm kinda spoiled when it comes to anything aerodynamics-related but this is just wrong.

Knowing the physical background of this phenomenon I want to try and fix it.
Before carving vent ducts into the hood I'd favor opening those sharkfin side panels the BRZ generously already provides.

I'm thinking of opening the fake plastic... "mesh"... , exchanging it w/ the real thing and then installing a kind of tunnel to the engine compartment. I hope that this will relieve the difference in air pressure created by air being forced into the engine compartment.

That should equalize the pressures at least enough th make 200km/h w/o trouble.
However, does any1 know whether it'd be possible to create such a venting system? I don't know how the area behind the side skirts looks so any insight would be appreciated. Also, if you've already solved said issue, let me know.

[Calin]

I've never heard of this issue before, but I'd imagine I'd have a heart attack if my hood opened at high speeds and slammed into my windshield.

[Basti]

I guess that'd be no problem as you'd probably crash right afterwards
However, as I said, the hood's still locked, its very light weight makes it susceptible to lifting (the same principle as on airplane wings) and, in my experience, messes up handling quite a bit. Actual lift is about 5mm tops.

In a local forum this topic has already been discussed, the aptitude to fix it is generally low due to the small number of owners.

[GTB/ZR-1]

You mean our cars go fast enough for that to happen? Lol

[Basti]

easily, really.

I never had the problem with my '95 Honda even at higher speeds but then again, the hood weighted about 4 times as much.

[CSG Mike]

We've had our car at 140+mph (racetracks! ) but I'm looking at the track, so I haven't noticed any hood lift...

[Gords_zenith]

Originally Posted by Basti

Dunno whether this comes up much butI've heard of this issue several times already:

Upon reaching more "interesting" speeds, the hood starts to lift slightly. Well, it's still hinged safely in place but when it happened to me on a particularily even strip of highway I got shaking from that interference and driving above that speed neither felt reassuring or safe anymore.
I guess it started at about 180km/h.

Now I know that I'm kinda spoiled when it comes to anything aerodynamics-related but this is just wrong.

Knowing the physical background of this phenomenon I want to try and fix it.
Before carving vent ducts into the hood I'd favor opening those sharkfin side panels the BRZ generously already provides.

I'm thinking of opening the fake plastic... "mesh"... , exchanging it w/ the real thing and then installing a kind of tunnel to the engine compartment. I hope that this will relieve the difference in air pressure created by air being forced into the engine compartment.

That should equalize the pressures at least enough th make 200km/h w/o trouble.
However, does any1 know whether it'd be possible to create such a venting system? I don't know how the area behind the side skirts looks so any insight would be appreciated. Also, if you've already solved said issue, let me know.

I was thinking the same thing, and from what I can tell, it's possible. Open the hood, and you can see where it appears Subaru have left gaps in the structure directly behind the vent. I think someone with enough dremal skills could cut a hole in the fender underneath the vent and then cut out the fake plastic vent and replace with a black wire mesh; voila all done. The only thing that stops me is now there will be a stream of hot air coming near the window, which could heat the cabin up if you drive with your windows down, which I like to do a lot.

[wbradley]

In Ontario (Canada) if you drive 180 km/h you might as well just give your car to the police since they will seize it when you are stopped, plus up to $10,000.00 fine for "stunt driving".

Even on the unrestricted stretches of autobahn, is this really the car to be burying the speedometer needle?

[OrbitalEllipses]

Originally Posted by wbradley

In Ontario (Canada) if you drive 180 km/h you might as well just give your car to the police since they will seize it when you are stopped, plus up to $10,000.00 fine for "stunt driving".

Even on the unrestricted stretches of autobahn, is this really the car to be burying the speedometer needle?

Got a 210kph ride in a turbo FR-S the other day...so I say it depends.

[Spaceywilly]

Try driving a WRX... with the hood scoop sticking out into the air it flops around like one of those crazy inflatable dancing car dealership guys. I don't think it's anything to worry about. Do you have a front lip spoiler? That would probably create enough downforce to get back the high speed stability, or even a downforce generating rear spoiler. When I put an STI wing on my WRX I noticed it felt a lot more stable at high speeds.

[Walldodger]

Originally Posted by wbradley

In Ontario (Canada) if you drive 180 km/h you might as well just give your car to the police since they will seize it when you are stopped, plus up to $10,000.00 fine for "stunt driving".

Even on the unrestricted stretches of autobahn, is this really the car to be burying the speedometer needle?

Do they really call it "stunt driving"?

But as for the side vents I think it would actually make a difference, for some cooling too. It's an idea I've been toying with as well.

[Supermassive]

Originally Posted by OrbitalEllipses

Got a 210kph ride in a turbo FR-S the other day...so I say it depends.

Lol yeah when i was getting my turbo tuned 130mph+ was pretty easy...the rear is a little floaty at that point though.

[Asphalt~86]

[OrbitalEllipses]

Originally Posted by Supermassive

Lol yeah when i was getting my turbo tuned 130mph+ was pretty easy...the rear is a little floaty at that point though.

The whole car's a bit floaty... that speed requires more aero and less complaint bushing IMO. A properly made diffuser (hint: I know some people makin' some, eventually) will help the floatiness in the rear.