LA964RS

I searched the forum and can't find it. But someone posted here the weight savings of plexi-glass replacing oem glass. I recall the weight savings was not as huge as you'd think. Anyone know this thread or have info on how much glass vs. plexi weighs? Interested in rear glass and quarter windows.

Thanks...any other crazy weight savings stuff appreciated.

SimonExtreme

I don't know the weight of OEM glass but glass weighs 2.4kgs per mm per m2. So on the RS's with their 3 mm glass rather than 5mm, you are saving 5kgs per m2 of glass. How much glass area is there on a 964? Conservative guess says over 3m so RS glass saves you about 15-18 kgs.

Now, I have read that plexiglass weoghs 50% of the weight of similar thickness of glass. That suggests that if you got the complete car plexiglassed, you would save, lets say, 30kgs compared with a C2.

However, you probably wouldn't plexiglass the front screen and you have an RS already so I am guessing that changing the rest would save you about 8kgs.

AVoyvoda

Not sure I agree, SimonExtreme. RS glass saves 4lbs per window. Don't know about the rear, but calculate the ensung savings from RS windows + rear (windscreen remaining unchanged) is around 15 lbs when compared to standard.

Superunknown

How about swapping the metal bonnet badge for a sticker?? Must save a bit of weight . . .

Geoffrey

I know that "plexiglass" is probably being used generically here, but just so no one is confused, you don't want to use it in any vehicle. You need to use a polycarbonate like Lexan brand for safety reasons. If I recall correctly, my polycarbonate front windscreen weighs 11lbs compared to near 30lbs for the factory glass. I hope this helps.

Tom W

Sepktyr says that replacing all windows in a 911 with their polycarbonate replacements will save about 20 lbs.

As an aside, I don't think you'd want Lexan on a street car. I wear polarized sunglasses and the Lexan window gives some pronounced schlieren lines. I notice them for about the first 2 turns in a race and then I tune them out. However, the adrenaline in a race is a bit different than driving on the street and I think it would bug me for street driving.

chancecasey

I had no idea this effect had a name, wow.

SimonExtreme

The problem is that I don't know the area of glass on a 964. However, I do know the weight of glass. I was also unaware, until Adrian's wonderful book came through my letterbox an hour ago, that the windscreen is the same as on a C2. Therefore my guestimates might be a little out!

Kahdmus

Why did you think it would be different?

LA964RS

Its fast Friday...anyone want to weigh-in on this one?

SimonExtreme

Because I knew that 964RS's had 3mm glass rather than 5mm and I thought it was on all glass!

N51

SHIELDS has polycarbonate available for the rear window in 3/16 or 1/4. Don't know the weight savings, but a call might help. Read somewhere, recently, that the rear glass mounted brake light should not be used with the polycarbonate. Another weight savings.

Noah

LA964RS

I'd planned on ditching the 3rd brake light...as it blocks my view a bit...never good when that could potentially cost you some $$ and points on the license.

JasonAndreas

Try to find someone local that can plasma coat the polycarbonate with Exatec 900 and you shouldn't have any problems with scratching.

pete000

For the street I am not sure plastic would be the way to go. I would suggest a Euro RS window with no defroster and thinner glass...If not that much lighter it would be megga cool. I want one too!