been toying with the idea of removing the old window, relocating the computer since im doing a 3800 swap anyway, reducing the width of the window a bit and putting in power assembly. I don't use the defogger anyway.
iv got a t top but would like to make it feel more like a real convertible wonder if it would just make the engine noise unbearable?
what do you guys think about the idea? suggestions ?
I don't think it can be done easily. Have a look at my cut away drawing here to see why:
The window is actually tilted 8 degrees forward at the top so unless you change the angle, you can only make the window retract into the engine bay, not the passenger compartment since the firewall leans the other way. Even then, retracting into the engine bay will present it's own problems since the deckild hinges will be in the way. You'd need to relocate them further apart, but then you'd need to reinforce where they attach to the underside of the decklid. Even if that could be done, I think you'll find that there isn't enough room around either engine's exhaust system to lower the window far enough.
The other impractical thing about a windowless rear is that the engine bay's heat will be sucked into the low pressure area formed inside the cabin.
It's a neat idea but IMHO it'll be very difficult to achieve, and the results may not be what you want.
You probably don't remember the 1957 Mercury Turnpike Cruiser.
It took a while for Ford engineers to realize that the negative pressure at speed was sucking the exhaust gasses into the cab and slowly killing the driver. Wind tunnels were not in common use then. By 1960 they got rid of it. A few years later they got rid of the electric window on the station wagon too. On a Fiero, your life-span would be noticeably shorter because you are pretty close to the exhaust pipe.
edit: I got there in the 1970s and saw some of the data. By then it had become folklore. There were no proven fatalities, but apparently some test drivers got a little loopy.
[This message has been edited by Gall757 (edited 04-19-2014).]
that is too bad. i may pull the window and try driving around without it to see just how bad it will be. the belt whine off the 3800sc alone will probably kill it for me. thanks for your replies and ideas
Exactly! I have roadsters and there is no problem with heat or exhaust fumes while driving. Sometimes when I'm stopped I feel heat waft forwards from the engine. Hasn't made me wish that I had a top on my Fiero.
that is too bad. i may pull the window and try driving around without it to see just how bad it will be. the belt whine off the 3800sc alone will probably kill it for me. thanks for your replies and ideas
A roadster may not be as bad as the rear windowless Fiero. The negative pressure may be higher on the rear windowless coupe. I say this because I drove a Fiero about 100 feet with no rear window and that was enough to convince me that I would not want that modification. Noise, and heat from the engine would make it a lot less enjoyable than you would first imagine.
i'm just going to have to give it a try its a fastback and i need to replace my sails so perhaps a scooped sail panel will change the pressure behind the rear window as well? I know nothing of aerodynamics so it will be a lot of try and guess work till i get fed up and put it back to normal
Was it Skytime's red Fiero (now in Florida) that had that rear sliding window? The rear window had a large middle section that can slide or move leaving a large opening.
Was it Skytime's red Fiero (now in Florida) that had that rear sliding window? The rear window had a large middle section that can slide or move leaving a large opening.
Your right about Skis GT. His slide rear window was something like the ones in the late model pickup trucks. Wonder if the engineers gave the low pressure condition any thought?
Spoon
------------------ "Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut
I have a del Sol, they have power rear windows. I often lower it in the summer and it seems a little cooler, if there is any paper in the car they blow around with the rear window down. Of coarse their front engine. If you could find one in a self service junkyard you could adapt the mechanism. Only trouble is you ain't going to find one in a junkyard.
thanks for the suggestion. I'll have to check those window dimensions. I'll find plenty in my local, for once i might be glad they throw tones of salt on the roads during winter
In the summer the "dead zone" around the center consol/rear window about kills me, just no air flow. I have thought about the rear window being able to open like a pick ups would be great till I did some searching on here... However I think we can all agree Fieros don't flow air into the cabin really... I always wondered about flip out sail panels, like the old tilt windows. As a side note it seems the negative pressure around the deck lid would be over come by air flowing through the rear window from the front windows right? Or just the sail panel idea...
I had a 72 corvette with removeable rear window. How are fumes supposed to get sucked into the passenger compartment with the windows down (!?) Even with the windows up, air flows into the compartment through the cowl under the windshield, past the passengers and out the B-pillar vents.
To the original poster, look through the History of SkiTime's car thread (18 pages, link below ). Maybe you can get more info on how he did it.
Originally posted by PaulJK: How are fumes supposed to get sucked into the passenger compartment with the windows down (!?)
At speed, the abrupt end of the roof line will cause the higher pressure air travelling along the roof to reverse itself into the cabin, taking with it some of the air from the deck lid vents. In stop and go traffic the lack of airflow also becomes a problem since an open rear window will allow the heat from decklid vents to radiate into the cabin. Ever watched the heat rise from those vents after you've parked your car? The bigger the engine, the more the heat.
Originally posted by PaulJK: To the original poster, look through the History of SkiTime's car thread (18 pages, link below ). Maybe you can get more info on how he did it.
I don't think he had the window roll down. IIRC, he had used a system similar to the OE sunroof, so that the rear window could be popped open, using the OE sunroof latch.
In the summer the "dead zone" around the center consol/rear window about kills me, just no air flow. I have thought about the rear window being able to open like a pick ups would be great till I did some searching on here... However I think we can all agree Fieros don't flow air into the cabin really... I always wondered about flip out sail panels, like the old tilt windows. As a side note it seems the negative pressure around the deck lid would be over come by air flowing through the rear window from the front windows right? Or just the sail panel idea...
I think that the t-top with the tops out and the windows down would be like my roadsters.
When I bought my second Fiero I ended up driving it 14 miles with no rear window or sunroof. I didn't notice any real heat but there was so much exhaust from the missing manifold and Steam from the leaky radiator cap that I had to drive with my head out the window.... course the front calipers were locked up and brake smoke was still blowing in my face..... anything from the engine compartment will definitely come in side.
Be Careful. May cause exhaust fumes (CO etc.) getting into cabin. Fiero cabin is very small and why cabin has fresh air flow at all times, even when ac/heat control is off.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Be Careful. May cause exhaust fumes (CO etc.) getting into cabin. Fiero cabin is very small and why cabin has fresh air flow at all times, even when ac/heat control is off.
This is already an issue with the Fiero, sitting still in traffic. In all the Fieros I've owned, I've always been able to smell the exhaust through the sunroof, side window, or sometimes it will get sucked in through the b-pillar vent.
1. the heat will be terrible. like sitting by an open oven door 2. the noise would be louder, but doable 3. the fumes will at the least make your eyes water, if it dont put you to sleep. Even the minivans and SUVs with opening rear windows have a placard on them saying DO NOT OPEN while driving.
The old Lincolns and Mercurys didnt have a problem with them because they were so big and the engine was in the front. I had 2 of them and it was nice to open it in town..even in the rain in the days before mass A/C. On the highway it did suck in tons of dust and dirt. The rear seats and headliner would get filthy.
[This message has been edited by rogergarrison (edited 04-21-2014).]
Originally posted by rogergarrison: 3. the fumes will at the least make your eyes water, if it dont put you to sleep. Even the minivans and SUVs with opening rear windows have a placard on them saying DO NOT OPEN while driving.
That is nonsense. If the fumes are bad enough to do that from the rear glass not being there, they will be bad enough to do that with the windows down or the sunroof popped. Or your engine has some problems that need corrected. Having a working catalytic converter and good mufflers is a really good start to not having exhaust fumes being an issue. Fix whatever is destroying the cat as well, because burning oil/coolant is going to damage the cat and cause it to get plugged up. Any "do not open while driving" warning about rear windows in SUVs/minivans probably has less to do with exhaust fumes, and more to do with big gaping hole for things to fly out of, at the back of your vehicle, in terms of safety warnings. Never had a problem with exhaust fumes coming in the rear window in the Jimmy I drove 15 years ago, nor any of the times I ever rode sitting on the floor in the back of an SUV with the window open. Nor do the exhaust fumes cause my eyes to water or me to pass out, when I roll down the rear window in my del Sol. And I'm sure millions of drivers of El Caminos or small pickups, also never had any such issues with the rear window opened up. Certainly never did in any S-10s I've ever driven.
You are dead wrong, pun intended. A flat rear window pulls dirt and fumes in like a magnet. Why do you think they tell YOU not to open the rear windows (NOT the rear SIDE windows) when driving ? Take your back glass out or drive your SUV/Van around with the back opened and see how long before you pass out, or get sick...eyes watering at the very least. The exhaust fumes come straight in the back. The fumes do the same exact thing that dirt does. Ever drove a van down a dirt road and you see the rear is covered with it in just a few minutes. Your welcome to do any research and post anything that says otherwise. Why do you think they put the stickers on them....afraid someone might fall out of a 3" opening ? The sticker is on a new vehicle with no miles, so Ill guess theres nothing wrong with them. Ill bet pickups with opening rear windows tell you in the manual NOT to drive with it open. In fact I take a look in a few myself. So you made it this far. Lots of people have lived thru heroin too...lots havent.
AEN 208 excerpt :
"When a vehicle is moving, holes or openings in the rear of the vehicle are under a suction which pulls in exhaust fumes. All holes in the car body must be sealed. The suction effect applies when a rear tailgate window or the trunk is left open or when persons ride in the back of a pick-up truck under a topper. The suction produced as the truck is driven and the lack of ventilation in the topper combine to produce a potentially deadly combination. Normally active children who sleep while in the back of a pick-up may be sleepy because they are breathing carbon monoxide. In California, several cases of children dying in the back of pick-ups under a topper have been documented."
excerpt: ref 1.1.Baker SP, Fisher RS, Masemore WC, Sopher IM. Fatal unintentional carbon monoxide poisoning in motor vehicles. " Any moving vehicle with a vertical rear tailgate or door (e.g., a station wagon or pickup truck with a camper shell cover) creates negative air pressure behind it. Because of this vacuum, opening the rear window of a camper or station wagon can result in high concentrations of exhaust fumes entering the vehicle. "
excerpt : Nissan.org "On 1970-78 Zs, having some exhaust fumes inside the cabin is quite common. These years of Zs all had the same body design and that original design is dated back at least to the late 60s. The way the fumes can get into the cabin is from one of the rear seals or a combination of some of them. If a seal is bad and you roll down a window, often times, more fumes come in. This is due to the low pressure area that is created from the air rushing over the top of the hatch and the air coming from under the body. The air directly behind the tail lamps is not moving and if a window is opened, then the air rushing by the open window actually allows the air that is sitting behind the tail lamp area to enter by the bad seal and get into the cabin (which would be a low pressure area.) So if you do have fumes getting into the cabin, then it is better to roll all windows up and turn on the blower fan until you get the seal(s) replaced.
The most common seal that allows fumes into the car is the rear hatch seal. That seal is the one that goes around the opening of the rear hatch. The rear hatch seal is a rather expensive seal but will last a long time if a new one is installed. Try to avoid buying the aftermarket rear hatch seal as they often don't fit well.
Another area that can let fumes in is the seal between the tail lamps and the body. This area is often overlooked because you can't directly see the seals without removing the rear trim or tail lamps themselves. "
I ran across another article that says in some states its actually illegal to drive with rear window open. I couldnt get the page to open to quote it.
[This message has been edited by rogergarrison (edited 04-22-2014).]
I've stated my experience with no rear window on my roadsters. It is not theory. It is fact. In my Lambo replica I don't even experience the typical wind hitting the back of my head that is so common in convertibles. If he didn't have a t-top so that he could introduce air from the front I would be in complete agreement with the naysayers. I say go ahead and try it. Otherwise we are just arguing paper theories.
Excerpt from Honda SUV owners manual, page 54 : Sorry thats the only one I have available at this time. This is the fact, not theory.
" Your vehicle’s exhaust contains carbon monoxide gas. With the tailgate open, airflow can pull exhaust gas into your vehicle’s interior and create a hazardous condition. If you must drive with the tailgate open, open all the windows and set the heating and cooling system as shown below. "
Different vehicles may behave a bit differently due to different aerodynamics. Obviously a Lambo has different airflow than a van or pickup. This also is not a big effect if you have other windows or sunroof open. You wont get asphyxiated in a convertible...or a Lambo roadster...even if you ran the exhaust pipe into the passenger compartment.
[This message has been edited by rogergarrison (edited 04-22-2014).]
I've stated my experience with no rear window on my roadsters. It is not theory. It is fact. In my Lambo replica I don't even experience the typical wind hitting the back of my head that is so common in convertibles. If he didn't have a t-top so that he could introduce air from the front I would be in complete agreement with the naysayers. I say go ahead and try it. Otherwise we are just arguing paper theories.
Well since we are arguing paper theories, what is the design of your roadsters? They evidently are non-stock bodies, what is the configuration of the engine vents? What are the aerodynamic characteristics of the body? What size engine? What type of exhaust manifold? There are too many unknowns to draw any definitive conclusions, so no I don't except your one data point as fact. I drove a 100% stock 4 cylinder Fiero with no rear window and within minutes I felt heat like a mofo...that is a fact.
Another fact...Falcon Fiero had a removable rear window on his chop top and didn't like the heat and had it sealed up.
I can see that happening with your t-tops in place and the windows rolled up.
The car I'm talking about was a T-top with no glass installed whatsoever (no windshield, no t-tops, no side glass, no rear glass,) and the heat was a still a problem after running the car for just a few minutes.
Just dont call something 'nonsense' when known facts contradict your opinion. I do stuff myself that supposedly cant be done. ie/ painting basecoat/clearcoat finishes over lacquer primer. Every paint store tells me it will peel right off. Ive been doing it since urathane was invented and not one peeling yet. I did my own present car almost 10 years ago, daily driver in all weather and barely a chip anywhere. One of my SLs was painted almost18 years and was still a showcar with 250K on it.
Just dont call something 'nonsense' when known facts contradict your opinion. I do stuff myself that supposedly cant be done. ie/ painting basecoat/clearcoat finishes over lacquer primer. Every paint store tells me it will peel right off. Ive been doing it since urathane was invented and not one peeling yet. I did my own present car almost 10 years ago, daily driver in all weather and barely a chip anywhere. One of my SLs was painted almost18 years and was still a showcar with 250K on it.
Never called anything nonsense. My opinions have been based on personal actual experience rather than theory. Nothing I have posted has been made up or theorized. I like theorys and I like to apply facts to them. Like I said I am amazed that a fiero with no windshield, no tops and the windows down would experience a backdraft. Amazed but not calling the story fraudulent. The story said the car was running. Does that mean that the car was in forward motion or just that the engine was running. I could see it happening if the car was stationary with the engine running.
[This message has been edited by dratts (edited 04-23-2014).]
Sounds like a pretty neat project,
The sticker is on a new vehicle with no miles, so Ill guess theres nothing wrong with them. Ill bet pickups with opening rear windows tell you in the manual NOT to drive with it open. In fact I take a look in a few myself. So you made it this far. Lots of people have lived thru heroin too...lots havent.
