At high speeds, the hoodvent prevents the headlight doors from flipping up and the front of the car from lifting due to pressure buildup. Also ensures better airflow through the radiator for improved cooling.
------------------ www.yellowfiero.com 17" DEZENT T wheels with 215/40 tires front and 235/45 rear, KONI shocks, EIBACH lowering springs, drilled/slotted rotors, SS brake hoses. PU dog bone, all bushings and engine mounts, K&N air and oil filters, Rebuilt&blueprinted V6, BORLA exhaust. Mercedes SLK yellow paintjob, Mr. Mikes leather seats, door skins, shift and e-brake boots. MP3 deck and custom subwoofer behind passenger seat, F355 style front, Aus' Stage 2 side scoops, "Fie Ro" extractor front scoop. Fiero Store rear swaybar, strut tower brace, black carpet, air intake. Rodney Dickman's competition short shifter, SS vacuum lines and deck lid strut. Billet aluminum dash kit from Kitcarman.
[This message has been edited by yellowstone (edited 08-18-2006).]
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05:51 PM
Electrathon Member
Posts: 5241 From: Gresham, OR USA Registered: Dec 2002
I drilled holes down throught the headlight well into the area in front of the wheel well liner. I used 1/4" holes X 48 in an "x" pattern. This equates to 3 sq in on each side. Seems to be good.
You could also just drill a big ol' hole and do much the same thing.
That being said, I'm still toying with the hood vent idea. Haven't decided whether I really want that look or not. The inset flame design with led blue lighting kind of appeals to me, and I really like Rockcrawl's vents from an esthetic point of view. But, venting out the bottom or back of the headlight well probably works about as good. IMHO
Arn
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06:02 PM
under8ted Member
Posts: 1108 From: Sparta, ON, Canada Registered: Mar 2006
Arn--Dont cut yours untill you get a good look at mine (if I ever get it back) "Nostril" design with blue neon lighting undreneath. I made a couple of boo-boos on the underside that are easy to avoid. I might even pick up another hood and re-do mine since they are bugging me not being perfect.
[This message has been edited by under8ted (edited 08-18-2006).]
At high speeds, the hoodvent prevents the headlight doors from flipping up and the front of the car from lifting due to pressure buildup. Also ensures better airflow through the radiator for improved cooling.
what are the advantages of having a hoodscoop or vent? ive been told it is a must but i dont know why.
i would like to leave my hood the they it is, i like the sleek look with no vent.
any info on this? is it neccesary? post some pics of hoodvents, maybe ill find one i like.
Ive heard people venting out the wheel wells or the 'compartment' area... Not sure if its any better, worse, or if any of it matters much and is just a 'urban legend'...
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07:30 PM
under8ted Member
Posts: 1108 From: Sparta, ON, Canada Registered: Mar 2006
What is high speed? I have done 80 in mine down the interstate and not had any lift in either the car or lights..
How much more cooling do you get, or do you have any measurements? ( to me, thats more important.. cooling is good .. )
About 70 or 75 notice that feeling where the front end gets light and it kinda feels like the car is starting to want to flip backwards ? that gets worse as you get faster.....its the pressure building up under the hood---the car is literally acting like a hovercraft. Venting gets rid of that little problem.
About 70 or 75 notice that feeling where the front end gets light and it kinda feels like the car is starting to want to flip backwards ? that gets worse as you get faster.....its the pressure building up under the hood---the car is literally acting like a hovercraft. Venting gets rid of that little problem.
I didnt feel it at 80.. perhaps a bit faster and i would ( but id also have got a ticket, or messed up the car with these bad roads out here. )But i know what you are talking about, i had my old roadrunner up to 120 years ago and it felt like it was going to fly off the road.
What is high speed? I have done 80 in mine down the interstate and not had any lift in either the car or lights..
How much more cooling do you get, or do you have any measurements? ( to me, thats more important.. cooling is good .. )
Drive 110+ and you'll have the headlights flip up on their own and scare the crap out of you. Not only that, but I think them popping up like that can break something. Pressure builds up under the headlights and to fix it you need to relieve the pressure.
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07:46 PM
Songman Member
Posts: 12496 From: Nashville, TN Registered: Aug 2000
I've had my car speedo buried and the doors didn't move. I don't know if some springs are more worn out than others or what..
To me, venting the air is about cooling, with a secondary benefit of looking good.
It possibly has something to do with worn-out parts. On my '88 GT I've pegged it and the headlights stayed shut. 'With the '86 SE, they popped up around 115.
About 70 or 75 notice that feeling where the front end gets light and it kinda feels like the car is starting to want to flip backwards ? that gets worse as you get faster.....its the pressure building up under the hood---the car is literally acting like a hovercraft. Venting gets rid of that little problem.
Something going on there Mike. It might be worn shocks. I've had mine to 90 mph and never noticed a light feeling at all.
Got a pic of those nostrils? Maybe I should drop down with my digital
some interesting responses. i have never noticed any lightening of the front end at speeds (max ive taken it is about 90mph). and i dont have any headlight doors to flap up anymore.
so... to the people that made them, did you actually notice any difference at all?? or is it just for looks.
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08:26 PM
AutoTech Member
Posts: 2385 From: St. Charles, Illinois Registered: Aug 2004
I don't believe hood vents are needed. The design by Pontiac works just fine for cooling. Lots of V8s are fine with the stock setup for cooling. A few have experienced headlight doors popping up. I have not with stock setup at over 100 mph. (Yes, I know my car is not stock anymore.) Redesigning a hood seems a bit extreme to take care of the headlight cover high speed problem. So it only comes down to are you willing to have your car repainted for body mods that are not needed but you think look cool. Guess you can tell which way I went. lol
------------------ Red 88 GT T-Top 3800 INTERCOOLED SUPERCHARGED White 88 GT Stock Please give me a rating if you appreciate my contribution. Click here to read the History of Skitimes Car
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09:43 PM
hyperv6 Member
Posts: 6113 From: Clinton, OH, USA Registered: Mar 2003
Hood vents really so work. But keep in mind it is not that big of a deal.
Most Fiero's deal with speeds 120 or less and you will notice a small improvment but not enough to make it a required addition.
They do remove the high pressure from under the front end of the car and improve cooling, These are true facts but your cor will work with or without them just fine.
As for the headlight doors it is a matter of spring tension on the doors. Worn and weak springs will let the doors flip up and you can loose a headlight door cover as it can rip off at high speed. I have hit top with my stock hood and never had a problems but have seen it on cars with higher milage where the doors flip up.
I have the vent fore what it is worth because I like it and nothing more. If you like them without go for it! Make your car your own and do what you like. Too many copy and do things just because they saw someone else making the same change. too few try to keep with original ideas anymore.
The one thing I did notice the vent make on hell of a bug deflector. At night the moths get half way up the hood and go straight up over the roof missing the windshield.
Bottom line from a vented hood owner you don't need them unless you want them. Same with the wing the aero effect under 120 in minimal at best.
[This message has been edited by hyperv6 (edited 08-18-2006).]
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09:48 PM
MiZer Member
Posts: 1673 From: Chilliwack, B.C. Canada Registered: Jun 2003
Regarding the headlight door problem I should add that I take my Fiero to 120+ MPH sustained speed pretty much every time we go on a road trip (yes, with a rebuilt 2.8 V6). That's why I invested in a solid suspension and brake setup, as well. I must say that the modified nose and the hood vent have taken care of the "flip up" problem but the car also feels much better at high speeds, especially when cornering (I'm talking about these long high speed corners on the Autobahn).
But I second what has been said: Not necessary, especially in the US with the tight speed limit and cowboy cops :-)
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02:24 AM
PFF
System Bot
Jermz238 Member
Posts: 1637 From: Newark, California Registered: Jan 2006
i've had my headlamp doors stay closed at 125 and i've had them fly up at 80. granted i was going into a 50+ mph headwind on the latter (damn benicia wind tunnel on 680)
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02:40 AM
DRA Member
Posts: 4543 From: Martinez, Ga, USA Registered: Oct 1999
There is a particular road here that runs along the Savannah river called Riverwatch Parkway, kinda scenic type divided highway that runs from Columbia County to downtown Augusta with no lights or turnoffs for the most part. It was built to alleviate traffic on Washington Rd, mainly during Masters week. It has several "S" turns in it and has been the location of several single car/motorcycle accidents (lots of white crosses and mangled guard rails). To the point......
I had a beat up 88 2.5 5spd that was real "floaty" through those turns when running 70 - 80mph (almost topped out LOL). I replaced bushings (poly), worn balljoints, cut springs, new shocks/struts, proper alignment, put on aero package, and added a vent to the hood. There was a night and day difference obviously but was not sure if the vent actually did anything. The front end of the car just seemed more "planted" and steering was firm and responsive.
I just made similar changes to my GT, car feels tight and very reponsive in tight turns under accleration and feels good at higher speeds on the interstate, but those "S" turns on Riverwatch still feel a little iffy at 85+ mph, seems like the frontend is "light" and the steering reminds me of driving a truck that is overloaded on the back. At lower speeds the car seems very sure footed and the suspension is tight. I'm considering some kind of vent for it in the future but nothing as extreme as I was working on with the 88 (you could see the radiator and fan motor through the vent). I'm fairly confident that the air flow over the hood will help some. The car is handling better on that road now with the changes made to it but there seems to still be something lacking at higher speeds on sweeping "S" curves.
A lot of this is measured by the "seat o' da pants" meter and it may be a placebo effect, it would be nice to see some actual windtunnel testing on mods to help with downforce on the front.
The 87GT I had was routinely run up to 120 on the interstate and I never had any problems with the lights popping up, that issue I would think is due to worn or fatigued parts, although I'm sure at some point they would finally give in anyway.
PS I really didn't answer the question did I? I don't see them as neccesary, but do think they help with downforce at more extreme speeds, when driving within' the speed limit I am sure the car is more than capable without the help but they sure do look cool if done tastefully! ------------------ Don't take life too seriously -- you'll never get out if it alive.
[This message has been edited by DRA (edited 08-19-2006).]
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02:57 AM
Jack Cooke Member
Posts: 564 From: Vale,N,C. USA Registered: Feb 2002
I have never had the lights to pop up on "Spirit" but the front end sure would get light past 100. I made one of those chin spoilers from an old GT nose and it cured the problem. It is as stable at 120 as it is at 50 now. Also I do have a vented hood which is to help cool the 4.9.
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09:58 AM
Aug 21st, 2006
fierosound Member
Posts: 15206 From: Calgary, Canada Registered: Nov 1999
I had headlights popping up but didn't want to put vents in the hood. Excess air pressure can be vented into the front fenders. Click the bookmark for "Radiator Vents" for pictures. http://fierosound.com/moreMODS.htm
------------------ 3.4L S/C 87 GT www.fierosound.com 2002/2003/2004 World of Wheels Winner & Multiple IASCA Stereo Award Winner
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12:18 AM
Pyrthian Member
Posts: 29569 From: Detroit, MI Registered: Jul 2002
the Hood Vent is a great thing. it keeps the nose planted. at 100 mph, with a good size hood vent, the car will feel likes its pinned down by the front.
and for the people without hoodvents who say "mine feels fine" at 100 - trust me - no it dont. much like convincing some of the old diehards to switch to DVD from VHS. I know you dont notice it now. wait untill you try it. just trade hoods for a weekend. 4 bolts.
most smaller & average size hood vent dont require any other changes. the larger hoodvents require cutting of the wall between the radiator & spare tire tub.
look at ANY current rear/mid engine car. its got a hood vent. and its not because its cool to have.
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09:44 AM
Blacktree Member
Posts: 20770 From: Central Florida Registered: Dec 2001
When I installed my hood vent, I noticed an immediate change in average coolant temperature. Beforehand, the temperature needle would hover just below the 220°F mark. Afterward, it instead stayed halfway between the 1/4 mark and the 220°F mark... as long as the car was moving. It's a small difference, maybe 1/8 of the temperature scale, but noticeable.
Now, before you start blaming old parts for the temperatures I was getting beforehand, let me explain that before installing the hood vent, I completely refurbished the cooling system. That included all new rubber hoses & clamps, new radiator & cap, new 180°F thermostat & cap, new overflow tank, and new water pump.
Later on, when I swapped in the V6, I had to trade up to a 195°F thermostat because the ECM kept dropping out of closed-loop mode. So yeah, the hood vent helps with cooling.
[This message has been edited by Blacktree (edited 08-21-2006).]
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12:39 PM
Fie Ro Member
Posts: 3735 From: Soest, The Netherlands Registered: Sep 2001
I also have a "Fie Ro" style vent And I think it works, at least it feels like it does. The headlight doors used to pop up at around 100mph and thats history now. It also feels like the front "grabs" better.....of course more noticable at higher speeds I happened to come back from a spirited drive last week and noticed the fan was on so I held my hand on the vent. I was pretty amazed how much hot air got moved out of there.