Lexan

[TexSquirrel]

Has anyone used these?
http://www.plastics4performance.com/...ndow-kit.html?
Seems like a good way to drop some weight after carbon fiber hoods and trunk.

[383backinblack]

Lexan is great for race cars, where you're ok changing the windows now and again. It's definitely not as clear as glass, it's harder to clean, and it scratches really easily.

So if you drive it on the street maybe not ideal. However, if you're ok with those things nothing wrong with it, besides possible legality. I don't know about these parts specifically, but in general Lexan window replacements are not known for their excellent fitment, either.

[lowside67]

Another challenge is that it's very hard to make them seal as side windows in the doors given that they go up and down to fit under the rubber.

They also don't save as much weight as you would think - they are usually on race cars as a safety feature, not a weight savings. You need metal braces in the middle of the span for the windshield and rear windscreen.

We did them on my E36 racecar and it was a pain - we made the decision to keep OEM glass on the windshield as it was not much heavier and is way easier to clean and see through (windshield wipers = fail on lexan).

I would highly not suggest lexan for a street car of any sort.

Mark

[Jazzy]

After a few years of competing in D/F stock, finally decided to take the next step and move to STU. So I ordered and installed 18" 8.5F 9.5R apex wheels, tck double adjustables with 350F/600R springs and vorshlag camber plates set to max camber at 2.25. Kept the same tires 235/40F and 255/35R and hope to go to 245 or 255 when the current set is done. I had two back to back weekends with autocross events, which was perfect for testing the new mods. Our typical runs are about 50 sec, so according to my math I need to gain about 1.5 sec to break even on pax.

Event #1. My only experience in adjusting shocks was with the koni yellows, which was relatively simple as there was only one adjustment and basically it was soft up front and stiff in the rear. Never had coilovers before, so I wasn't sure how much of a difference the stiffer springs would make. I decided to keep everything full soft (about 1/4 turn in rebound from soft on all four corners). The car "felt" quicker, but it now had much more understeer. Almost like it was in full stock form. Thinking back, I think the car felt faster due to the course design. The course had some much faster sections than usual and I thought I was quicker coming out of sweepers because I had a few hundred RPM more than usual and much quicker acceleration as a result. In reality, I was a lot slower and the results showed. I took my raw time and converted using the F stock pax and this would have put me quite a few places lower than usual (though this is not scientific at all, I know where I usually stand with the other competitors). So now I am going slower than before the mods.

Event #2. Dialed up compression to 3 clicks all four corners and rebound to 1 1/4 turn in the rear, left front as is. Now the car felt back to where it was before these mods in terms of balance. This was more of a typical course and for sure the car handled slaloms and sweepers a little better. Was quicker coming around sweepers and could get on the power a little sooner. Using the F stock pax again, this would have put me slightly higher than usual. I figure only about 0.5 sec faster. Next event I will try more compression and rebound in the rear. Does anyone have any recommendations on shock setting? During this event, I got a chance to sit with a fellow STU competitor in a 08 M3 and the one thing I noticed was how much better his braking was than mine. Both of us are on stock brakes, and no doubt the M3 should have better braking, but the difference surprised me. Might have to put a higher priority on pad upgrade.

[blinded]

Seems Jazzy found the wrong thread. Back on track, our race car has lexan. Replacing the rear glass and hatch frame (not a bmw) was a big weight savings. The windshield not so much. It's nice to be able to pull it off and work back there but that's the only nice thing I have to say about it.

[Jazzy]

Sorry, reposted in correct thread.

[TexSquirrel]

I've raced before, but all my cars (that had windows) had OEM glass.
I figured that Levan would be a lot lighter.
I guess carbon fiber hood and trunk, lighter battery, lighter seat, and ditching the interior are the only things I can do to lose weight.
I have a non-electric sport seats.
I'm not sure how much it weighs, but I'm sure I can find a lighter (and probably uncomfortable) seat.

[lowside67]

Originally Posted by TexSquirrel

I've raced before, but all my cars (that had windows) had OEM glass.
I figured that Levan would be a lot lighter.
I guess carbon fiber hood and trunk, lighter battery, lighter seat, and ditching the interior are the only things I can do to lose weight.
I have a non-electric sport seats.
I'm not sure how much it weighs, but I'm sure I can find a lighter (and probably uncomfortable) seat.

I, and many others, find that a race seat that fits you well can be incredibly comfortable - I love the Recaros I had.

And going from the non-electric sport seats to race seats will likely save you more weight than the lexan and is infinitely more streetable.

Mark