VW Lupo 3L --> 2L

[RedDevil]

Now you've lowered the roof, you need new side and rear windows.
You've thought about Lexan (polycarbonate) I guess? Twice as light as glass and yet strong and safe (as opposed to other sorts of clear plastic - I know, I've been searching).
One possibility that might just work well with a severely hatched car like the Lupo is to make the rear windows curve in slightly towards the rear, allowing some air to flow between the rear pillars and the resulting (narrower) rear window. This should reduce the wake behind the car somewhat.
This is not feasible if you want to retain the possibility to carry passengers in the rear of course as it would compromise their safety. But I guess you've already removed the rear bench; then it should be fine.

On second thought; this shape looks like it could be extended with a nice boat tail perfectly.
Whatever way it goes, I like to see what happens (subscribed!)

[Vekke]

Front windows will be 2mm clear polycarbonate and will see if that is strong enough. Already cutted and waiting for glue tests... Rear glasses carbon or tinted polycarbonate. Have not decided yet.

Trunk will get some extension to the boattail which will be tuft tested.

[JohnAh]

Polycarbonate windows sounds like a good solution to me but is it allowed in Finland? I´m quite sure that in Sweden where I live it´s not allowed to replace glass with plastic except for windows behind last passenger seat. I find this annoying since polycarbonate would be at least as safe as glass, probably safer. I guess this rule is a leftover from the days when clear plastic ment acrylic which can break into realy sharp pieces.

Vekke, your project is realy appealing to me. Good luck with your improvements! *subscribed*

[JohnAh]

Excuse me for not reading the entire thread in detail before writing this, but someone mentioned alcohol injection and I recently read an old but rather interesting book about alternative fuels where I found a warning about adding fuels in to the intake air on a diesel engine. In the book they had made tests with propane/LPG and "wood-gas" as the main fuel together while only a small amount of diesel were injected the normal way to act as an ignition fuel. This definitely works and the diesel engine can deliver more power than normal but since all fuel is burnt rapidly the "diesel-knocking" becomes hard, increasing the wear of the engine.

I guess adding methanol can work great as an intercooler but it may also give an uncontrolled and rapid combustion that can damage the engine.

[Vekke]

Yes gases can burn faster but wear engine faster, but if OEMs are starting to build them that is nothing special. Ofcourse I would like to read that study to know better.

PC is not allowed in road use in Finland either and so is many other things in this project. Those are just laws that slow down the evolution and if you decide not to follow some of them you can find great new innovations, which can be legal after laws are rewritten. Somebody has to be first to do something.

[Vekke]

Summer is coming and I am hopeful that next week I will be able to make first tuft tests to my roof chopping and kammback. This weekends target is to get the windows installed and paint the modified parts black like the roof.

Car should be ready for real driving within next 3 weeks so I will be busy. I am hoping to break the magigal 100 MPG with first tank even its still cold weather.

[JohnAh]

Originally Posted by Vekke

PC is not allowed in road use in Finland either and so is many other things in this project. Those are just laws that slow down the evolution and if you decide not to follow some of them you can find great new innovations, which can be legal after laws are rewritten. Somebody has to be first to do something.

That´s the way to go! When breaking laws I think it´s important to spend some thoughts on who or what they are ment to protect. If the answer is "yourself" I see no harm in challenge them. Removing front discs and calippers to save weight (since you rarely use them) would be a lot more stupid than removing all windows or replacing them with a weaker material.

15 years ago and more, when I made my most crazy things with cars, the "Swedish car approval institute" (Svensk Bilprovning) would often reject an old car with some rust holes in the sills or wheel arches but nowadays they have adapted to the fact that it takes quite large holes before a car starts falling appart. 15 years ago the car would also be rejected if your wheels were widened (actually track width) more than just 20mm or so. Now they don´t care as long as the tires are covered by the fenders. Perhaps things are going the right way sometimes for us who likes to modify our vehicles...

[JohnAh]

It´s probably illegal (may be seen as fraud) in most countries but having an extra car of same type and colour in stock condition just for the annual visits to vehicle inspection may be a solution for almost absolute freedom. Just make sure that all identifications such as chassis number and licence plates are duplicated. -And NEVER take both cars out from the garage at the same time!

[AndrzejM]

Originally Posted by JohnAh

Removing front discs and calippers to save weight (since you rarely use them) would be a lot more stupid than removing all windows or replacing them with a weaker material.

I think that 2mm thick polycarbonate is much stronger than regular car glass pannels.

[RedDevil]

I just wonder what happens if you hit a reindeer.
I've been to Finland and almost got stampeded by a herd of those, luckily I had already slowed down a lot so it was a miss. Just half a kilometer after that the first and only 'Beware of reindeer' sign I've seen those 2 weeks.
2 mm seems very thin. The hardware stores over here don't sell it that thin. A 4 mm PC windscreen of about 1 square meter would weigh just under 5 kilo, wouldn't skip safety for a few kilos less than that.
I've seen at least 500 'Beware of moose' signs and 0 moose. You'd need at least 1 cm of thickness for those, I guess.

Getting the PC to bend in shape, that's another story. You'd need to cure it at almost 200 C. You need a really big oven.