I have a porsche 944 that I'm swapping a ls1 v8 into eventually. My front window is currently cracked and I thought putting in a lexan window would be a good idea. The guys on the porsche forums say otherwise. Here's what confuses me. I can buy a 944 porsche lexan windshield or rear window from a porsche dealer and the forum members say it'll scratch like crazy even with the films and protective shields. This confuses me since I know off-road and rally guys use it all the time. Can I get my hands on some lexan (nascar surplus) and make myself a window that will stand a windshield and daily driving to work? I also would love a rear hatch but that is extremely curved and there's no way I can just bend it, I'd have to form it which I've heard is a little bit of a pain.
Raze
SuperDork
9/5/12 9:13 p.m.
I think this should be over in the GRM board instead of in the build projects...
bp944
New Reader
9/5/12 9:22 p.m.
Sorry, I'm new to the forum. Can a admin move this or should I repost in GRM?
It will scratch easily and will get pitted easily since it is softer than glass.
It may not actually be legal in your area, check first. And yes, it'll scratch, especially when you use your wipers. Save the Lexan for the side and rear windows instead.
The rally and off road guys that have Lexan windshields replace them multiple times in a season. They really do scratch super easy.
Off road guys don't use windshields (helmets with visors and tear offs), rally cars use regular laminated safety glass. They do have lexan side and rear windows though.
If you wanted to test durability of lexan as a daily windshield, buy a small piece at HD or Lowes and tape it down to you regular windshield and drive it for a couple weeks. Run the gas station squeegee over it and a few cycles of wipers. You would only be in it for $5 and no effort. If it works, go for it, if it is streaky and pitted, you saved a bunch of heartache from building an expensive piece for a DD.
Yes Lexan will scratch, and will scratch REALLY bad with wipers running across it. Lexan windshields in race cars are considered to be a consumable item, and get changed often just like changing the brake pads, etc, and I'd guess that would be alot more often then you'd want to do on a street car.
They do sell products to polish the scratches out of lexan (Racecar Engineering sells it), similar to those headlight de-yellowing kits, which might buy you a bit of longer life.
If you decide to go that route, get yourself a good sturdy piece of craft paper and make a template of your existing windshield, use it to cut out your new lexan windshield, and then roll the template up and store it somewhere safe, because you will need to replace the Lexan again sooner than you think.
We used lexan windshields in our stock car. They didn't live very long lives.
The glazed ones sold by 5 star bodies:
http://www.fivestarbodies.com/store/index.php?p=product&id=484
hold up to about 2 seasons of racing. The wiper does not damage it nearly as much as I would have thought (observed, my car has no wiper) but if they are dirty and you grind it in trying to clean them you will scratch the hell out of it. You have to keep it covered on an open trailer to minimize damage. They suffer rock dings much better than glass (no cracking, just scratches) so for a dedicated race car tend to cost the same or less as using glass but are lighter. I was using 2 to 3 $90 cheap chinese glass windshields in my E30 in a season due to cracks from thrown rocks so it was the obvious choice for me.
For a street car - you would be nuts to put it in. Seriously. Just put cheap aftermarket glass in it from the local chain. It's free if you have comprehensive.
Lexan is an easily-marred costly PITA material that rarely saves anyone any money. You should only use it in a dedicated track car if saving a little weight is worth a lot of money to you, if you have a problem with rock strikes but don't use your wipers, or if the rules require it.
There is "scratch resistant" lexan. It is crazy expensive, and I don't know just how "resistant" it is.
poopshovel wrote:
There is "scratch resistant" lexan. It is crazy expensive, and I don't know just how "resistant" it is.
Yeah they have a ceramic coating, powerboat shops can modify lexan sheets like this for you. Crazy expensive but about as scratch-resistant as glass from what I hear. Also I imagine this coating might crack while the lexan underneath flexes...
amg_rx7 wrote:
It will scratch easily and will get pitted easily since it is softer than glass.
I'd imagine wipers would all but destroy it.
Edit: Just saw Keith's post directly below the quoted. I read good.
To the OP, any particular reason you're hellbent on the lexan? I think you'll find the weight savings isn't significant enough to make it worth the pain in the ass/cost.
