Polycarb windows - worth the hassle?

[sniff petrol]

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I've been investigating getting some 4mm polycarbonate windows for my 205 GTi track car. The car's meant to be a bit of of a bargain track shed so I'm reluctant to spend too much on it, the theory being the cheaper the car the harder I drive it. It's already fully stripped of all non-necessary bits.

Now I've had the opening rear quarter windows out and weighed them, and estimated the weight of the other windows based on them (assuming they're all the same thickness) and compared them to the weight of the 4mm polycarb. They are as followed:

Glass

-Rear side windows: 1750gms + 500gms of seal = 2250gms (x2)
-Front door windows: 3331gms (x2)
-Heated rear screen: 5609gms (x1)

---

So a total weight of glass currently in there is 16.771kgs

4mm Polycarb

-Rear side: 1150gms + 850gms of seal = 2000gms (x2)
-Front door: 2189gms (x2)
-Rear screen 3686gms

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So a total weight of using 4mm poly comes in at 12.064kgs

So the saving of using poly over glass is only some 4.7kgs at a cost of £70 for the sheets already roughly cut to size but me to finish off myself. Obviously I can then junk the front winder mechanisms and fix the poly in and use opening sliders to save even more weight.

To me the weight saving isn't as much as first expected, most people reckoned on saving 10kgs over the glass, and the poly is dearer than I was expecting. It's going to cost £15 per kg of weight saved, on a car weighing in at about 800kgs

Is it worth it?

[RT106]

It'll get scratched to f*ck before you know it. And those little plastic sliders are so annoying; they either stick or rattle.

How much more fun are you going to have minus sixteen kilos? If you were competing there might be some point, but even then I'd argue you should spend your money elsewhere...

[sorrento205]

if memory serves, the non opening rear quarters from poverty spec models are a lot better cost effective option for lighter glass.

[screwloose]

I wouldn't have said it was worth it. The more extreme weight saving measures, and I include polycarb windows in that, aren't really necessary until the use of the car becomes truly competitive or timed neither of which are possible at a track day. The driving enjoyment will certainly not better and if anything the polycarb windows will become the bain of every journey in your track car.
Looking at the weight figures you've quoted it only looks like there will be a weight saving of circa 4KGs! Just take youself off for a dump before each session in the car!

[GnuBee]

You don't need to use 4mm; you could drop to 3mm and it'll still be strong enough - obviously if you do that'll increase the weight saving.

The decision at whether it's worth doing or not is not just a case of the absolute weight saving in pounds/kilos but also a case of where the weight is being saved; In this case you're going to save weight from high up on the car which will lower your COG and should have a positive impact on cornering.

You need to have a think about how you're going to attach them to the car though especially if you don't want footwells full of water.

[sniff petrol]

If you lot seem to think that 3mm will do I'll try that, I saw most race regs are to 4mm so thought I'd need that. I have some proper seals to use so water ingress in not an issue, the car is garaged anyway and isn't used on the road.

I think I'll go for it then, the 3mm is a bit cheaper at about £50 all in and will save about 7kgs.

[tigger1]

Go lose a stone fatty

[sniff petrol]

tigger1 said:

Go lose a stone fatty

God you sound like my GF...