Neo914 single piece door windows, the plan at least... Options

[neo914-6]

New Porsches have done away with "vent" glass as have most modern cars so this feature should be on the Neo914. Apparently this has been done by someone in AK but was too much custom work such that it required constant adjustment and the fabricator would not duplicate them based on these problems. The person telling me the information guessed the donor glass came from a Jeep. Miles claims one was done with Miata door glass but they come with a vent window like the 914…? (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

Installing them will require a triangle "filler" so the front rail will have enough space to be mounted and there will be more than a "point" of the glass in the rail. There are two metal pockets that strengthen the hinges and there is a door stop mechanism which will interfere with a rail at the forward side of the door. Since the door is relatively short, there is very little room for structure below the window to firmly hold the window upright in extension. Some doors actually bond a mount up on the glass for the lifter. If I can’t find an existing side glass that works I'll go ahead and cut a plexiglass piece to develop the lift mechanism. If there is enough interest I’d consider having them manufactured. I’ve got tooling estimates and they can produce them out of tempered or laminate glass. A kit may not be feasible since the door will require cutting and fabrication to fit the glass, rails, and mechanism. It would likely be a complete door with core charge.

[aircooledboy]

Felix,

First, you are wasting your time looking at any window that has a frame. Here's why: If you remove the 914's vent glass, you will have a frameless door window. Frameless windows require alignment fixtures on the glass as well as the door frame to get them into the right spot and hold them there when they close, and to keep them in the right general orientation when they are open. Framed windows are held in the right position by the frame as the window goes up and down, and don't need or have the alignment fixtures. The frame steadys the glass while the regulator raises and lowers it. A 914 is a semi-framed window, because it uses the front channel between the vent and the door glass as the primary guide when the window moves up and down. A semi-frame window, like a frame window, does not need alignment fixtures. The problem with looking at a framed window as your donor is that you can't add the neccessary fixtures to a door glass that wasn't made for them, because they are attached using holes through the glass, and you can't add holes to a tempered door glass. Thus, you won't be able to take a glass from a framed door and make it work in a frameless application because it wont have guide fixtures, and they can't be added.

Second, my educated guess is that you would not be able to put a fully functional frameless glass in a 914 door for 2 reasons: 1. You would have a nearly impossible time fab'ing the necessary fixture guides into the inside of the door cavity. Those fixture guides are usually part of a pretty sturdy framework stamped into the door's frame. I think that would require a ton of pretty precise support engineering and fab, and in the end, a 914 door is just too narrow to accommodate the whole deal. Assuming you get past that hurdle, you get to the bigger obstacle; 2. Even when fully raised, frameless door glasses have a large portion of glass below the top doorline that would not likely fit into the short 914 door body. Frameless windows need a good 20%ish of their glass mass to stay inside the door even when fully raised to provide enough leverage for the fixtures to hold the glass firmly in place. A stock 914 regulator rests within an inch or so of the bottom of the door when the window is all the way open. That means that when you add the needed extra glass at the bottom of a frameless glass, you would not be able to roll the window all the way down, because the glass will bottom out inside the door. (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif)

Just my .02 based on my years in the auto glass trade. (IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif)

This post has been edited by aircooledboy: Sep 6 2005, 07:28 PM