Racing nuts,

I'm looking to outfit my 914 with a lexan rear window. Any comments on availability, road noise, and street legality, and installation would be much appreciated.

I've found information on front windshields on the net, how about side,vent, ect..




Thanks, Chris Julian

I'm also planning on replacing my rear window with Lexan when I connect my cage to the rear shock towers in a couple of months. I hear it's not a good replacement for the windshield though because of scratching. I know that my glass windshield is so full of chips from the last two years of racing that I would be afraid of using Lexan there.

I made all exept the windshield from lexan. Just use the old glass for templates.

Windshield came from racingshields. Very nice, fit perfect. Comes coated to prevent scratches and so far looks great.

Got the lexan locally at a lucite/plastic shop for less than $100 for 4'x8' sheet.

dr

Check with this company:

http://www.spektrproducts.com/catalog.asp


choose Porsche 914

Synthesisdv; how long have you had the windshield in place, and what do you clean it with? Could you post a pic of where your cage connects in the engine compartment?

Had the windshield 6 months. Installed it with lots of nut plates which took a long time but should make it easier to sevice. I was still able to use the factory clips and metal trim. Wanted to keep it looking stock for vintage class.

I just baby it. Bring lots of clean rags to track and use lots of glass cleaner. Haven't had to use the wipers yet but the manufacturer says go ahead, no problem.

rear bars go to 1/4" plates at front of wheel well. Rules don't allow us to go to suspension pickup points. Bar is bent so we could operate the lid normally, worked out perfect for us.

dr

I had a plastic front windshield in my 911.... After a few uses I took out the plastic and put the glass back in...


The plastic used to deflect at high speeds, and the view out the windshield became distorted.... I probably could have put a vertical rib to stiffen the windshield... but..

I haven't had that problem but my car isn't that fast.

They warned me about this which is why I ordered the thickest material, 1/4".

They also make 3/16 and 1/8.

Maybe you had the thinner type. Racing shields seems like a good company. They deal with pro race teams all the time.

dr

Mine was 3/16th's... on long straights as speed crept up over 120 or so I could notice the windshield starting to bulge in.... made me kinda nervous...


didnt want to be wearing my windshield

Thats why they steered me toward the 1/4".

Anyway, production rules require 3 1" wide aluminum strips inside the car supporting the windshield, and clips (5 I think) on the outside.

The lexan might blow out or in but it wont shatter. It actually has much higher impact and penetration resistance than glass.

http://racingshields.com/pc%20vs%20glass.htm

dr

I am due to pick up a sheet of Lexan and also some black ABS (for door panels) tomorrow at a SF Valley supplier. (Andy I think it is fairly close for you as well; ABC plastics on DeSoto somewhere near the Rocketdyne plant I believe).

BTW is a heated factory rear window worth anything i.e. even bother listing in the classifieds, or just trash it? I have the dash switch as well.

keep the window for a template.

I laid up some CF for door panels.

dr

Thanks dr - I actually "almost" tossed the window the other day (that was after my 2 yr old knocked it over on the garage floor; didn't break ) then I realized I would need it to size & cut the polycarb...Doh!

I think I also need some simple alum. straps to prevent "blow-out". Whether they are truly necessary or not, it was mentioned in several rulebooks I think.

I dropped mine twice and didn't break. Must be made of some uber glass.

I guess if something big like a tire/wheel hit the windshield, the straps would help alot. All those rules that seem wierd are there because in the past, some guy learned the hard way.

dr

this reminds me of an old experience...
there is a race car over here.. a 914/6 that used to run years ago and is actually being resurrected right now to come back to the track...

its a pretty big, tube framed monster with a lexy front windshield... At the big local track the glass would bulge in right before the braking zone and then when the brakes were applied it would pop back out.. quite a disturbing experience for the passenger, but it was securely fastened and never came loose.....

reportedly the wind force or aero drag would cause this at 170mph....

b

I was thinking today (scary when that happens) that if I just rivet the rear lexan piece to the window frame, straps should not be necessary. I can't imagine that the air pressure on the rear window is that great, and it is well shielded from projectiles. Obviously a windshield is a completely different story, but in the forseeable future I am going to stick with glass for that piece.

well, my rear is held in with nut plates, so I shouldn't talk but...

did you ever hear of a SPIN ???

You can get some 100 mph air blasting the rear of the car real fast. staps are on my list of things to do.

dr

here is another source

Racing shields

The straps on the rear glass , and the clips on the out side of the windshield are there to keep the "glass" with the car in case of a spin or loss of the windshield ( or rear glass if you happen to be going backward at a great rate of speed).
The rear straps look cool , are easy to install and keep the window from becoming a big sharp edged frisbee at 120 MPH.
All of those straps and clips are a good idea , IMHO.

Dave