Thicker rear window for 914 targa bar, Interesting idea… Options

[horizontally-opposed]

Noticed that this 914 build had a thicker rear window made, and it got me to thinking about whether that might help with noise in a six-cylinder car when the top's on?

http://www.914world.com/bbs2/index.php?sho...7&st=0&

Anyone have any experience with this. Is the 914's rear window truly flat, and therefore easy for an automotive glass shop to duplicate?

[Superhawk996]

Noticed that this 914 build had a thicker rear window made, and it got me to thinking about whether that might help with noise in a six-cylinder car when the top's on?

http://www.914world.com/bbs2/index.php?sho...7&st=0&

Anyone have any experience with this. Is the 914's rear window truly flat, and therefore easy for an automotive glass shop to duplicate?

@horizontally-opposed

I think you're aiming at NVH reduction previously discussed in the other thred. The common modern NVH solution is to use laminated side glass to reduce NVH into the cabin. The laminated glass is another form of constrained layer solution that decouples the two panes without the vastly increased thickness of two pane glass and it is more effective to boot.

[horizontally-opposed]

I think you're aiming at NVH reduction previously discussed in the other thred. The common modern NVH solution is to use laminated side glass to reduce NVH into the cabin. The laminated glass is another form of constrained layer solution that decouples the two panes without the vastly increased thickness of two pane glass and it is more effective to boot.

(IMG:style_emoticons/default/agree.gif)

Yup, I was, and now we're talking.

I suspect glass per your description + the right modern interior firewall matting + some sort of sound pad on the bottom of the painted section of the engine lid + the factory engine side firewall (mine is still there) would make a nice difference when the top is on, with little to no detriment to when the top is off. Was also wondering about the dual-pane stuff the German manufacturers make, but that might be a big job unless there's a way to add a second stock window spaced from the first and then mod the interior pieces to account for the added thickness? Downsides are weight and modding interior parts as well as figuring out how to add and support it to the existing window. And seal it.

I wouldn't say my engine noise is awful by any means, as I've got the stock airbox on a 2.2 with carbs, but I wouldn't mind cutting the interior engine noise (and it's mainly engine/fan/cam/chain noise I think?) when the top is on. My car was much nicer on the freeway as a four. A 5% to 15% cut would be fabulous, but I'd settle for just a bit of the edge off. Would make the car a lot nicer for long hauls with the top on.