No windows?

To jump right to it, I'm prepping an e36 for FP class autocross. The rules say I can remove the side windows. Most people I see with similar cars use lexan but I don't see it being much different than the miatas that run no windshield, no top, etc. Is there a reason I wouldn't want to run no windows on a roofed car? The car will live in a garage except for the 5 minute drives to local autoX on sunny days.

I would imagine you would create lift running without a windshield.

Without the back and rear side windows, I would imagine the wind would be more turbulent reaching the rear of you car and/ or wing creating more drag.

There was a car fire at Firebird a few years ago in a EG Civic Hatch. The rear window was removed due to the wing mounting coming through the back. When it caught fire under the car, you could see the flames come right in the back and up to the driver. I have to imaging this same force was slowing the car some. Link to video https://www.youtube.com/watch?v=upxA22rMvxQ

In reply to former520:

That was a pretty wild video. I wouldn't be removing the windshield, just the door windows. I see the drag argument but wonder how much it would matter at autocross speeds?

I know I hate them.. but consider using those Lexan "visors" that people put on their cars to keep the rain out when leaving them cracked open?

In reply to mad_machine:

That actually seems like it might be a perfect solution.

Back in the 80s.. fiat released the ultimate Strada (if you can remember those) in Europe to compete with the Golf GTI. In all respects except reliability, it was a better hot hatch than the golf.. it used something similar.

Behold the Fiat Strada TC 130

I ran the fastback Miata at the Challenge without windows.

I expected bad things- parachute effect, lift, turbulence, etc.

The car ran 4 mph faster on the drags with the top than without it.

The top was not sealed tightly at the rear.

For autocrossing, I don't think your speeds will be high enough to matter. I think you'd find a net gain because of weight reduction, but more importantly lowering the center of gravity.

The handling was noticeably improved on my MINI Cooper S with a plexiglass windshield (a few less pounds up high).

^I'm aiming to replace the rear quarter glass on my Corolla with Lexan to reduce high-mounted weight.

Removing side window glass entirely would be a nice weight reduction, if you don't need it.

Thanks, guys. It looks like we have the same thoughts on it. I just usually see people using lexan and didn't know if there was something I was overlooking. Other than its probably better if the car spends more time outside or is towed on an open trailer.

if you do go with sealed lexan vents.. Might I suggest these incase you get some air trapped in there..