If you decide to do this modification, the warranty may be voided on your aftermarket windshield. You may not get the same results. In other words, its at your own risk.
The problem I experience, is where the Bullet Speed Bimini Top combined with the F4+3 Windshield created a vacuum, reducing airflow to the cabin. The airflow was directed up the windshield and back over the top, leaving the cabin void of air entering in the front completely . This caused air to come back into the cabin from the rear, bringing in all kinds of things we didn't want. The reasons for modifying the F4 +3 windshield was two fold; I wanted to increase the airflow into the cabin area, and eliminate the backdraft of road dust, exhaust fumes, and road debris into the cabin.
For this project, I used:
1.) Bosch Jigsaw with Bosch blades (T102BF) specifically designed for cutting Plexiglas
2.) Lenox 1 1/8 Arbored Hole Saw
3.) Kobalt 4 in 1 Half Round File
4.) Various sanding pads, fine to very fine, with a foam sanding pad
5.) Drill with small drill bit for drilling pilot holes
Miscellaneous Items:
Clamps, Work table, Towel, Painters Tape, Compass, Fabric Tape Measure, Flexible Ruler for Straight Edge
First I need to find the center of the windshield, after coming up with varying measurements going edge to edge, possibly due to slight variances in manufacturing, and angling, I decided it best to use the windshield support/ screw hole as the center line.
I taped the windshield off off both sides, and taped more than I would be cutting to ensure that the jigsaw could not scratch the actual windshield surface.
My measurements for the cut: 8 inches at top edge, 6 inches at the bottom edge of the cut, with a depth of 3 inches. After marking it off, I did a visual test, to make sure the finished cut would be what I wanted to achieve. Wife put the official stamp of approval on it, so I proceeded.
Next, I taped off where my clamps would go in order to avoid scratches, Now, here comes the real technical part, I needed to make sure my pilot holes were where the Arbored Hole Saw bit would drill through. I used a compass set at the diameter of the Arbored Hole Saw, and overlapped circles to find the center... it works, don't ask me to explain it, but I can illustrate it for you... the circles pictured below all intersect at the center of each circle.
My reasoning behind the Arbored Hole Saw was for several reasons, I wanted a round radius at the corners instead of sharp angles , a curved angle will withstand more flexing than a straight angle while under stress such as wind or pressure; secondly, to be able to maneuver the cuts at the end of the horizontal lines.
Using a 1/8 " drill bit, I started my pilot holes for the Arbored Hole Saw bit, nobody likes to start drilling and have the drill walk on you...
Now for the Arbored Hole Saw drilling... and then the jigsaw. I practiced on a scrap piece of lexan plastic, to see what speed would be best on the jigsaw. If you cut too fast, it will melt or burn the plastic. Too low of a speed causing cracking, or chipping. I used one notch above low speed for my cut, medium low, or setting of 2 on Bosch Jigsaw.
With all the cuts made, time for dressing out the edge with the file, and sand. I left the tape on preventing an "oops" while sanding..
The Finished Modification... Wife gave the nod of approval. I get to go for a ride now...
Air wings are not made for use with tops, however many have managed to attach them successfully. Wife was not thrilled with the idea of
wind wings... so this is my Plan B.
Did this work?
Wife and I went for a ride upon completion, there was a significant increase of air movement through the cabin from the front.
This helped dissipate heat rising from the floorboards and console area. It noticeably decreased the amount of air reflux coming from rear.
However, the airflow sharply diffuses to a wider path just beyond the shoulder area, and does not carry air as forcibly or as directional,
beyond the rear fin area as I had hoped it would. I suspect that I will still have problems with debris on the rear deck area, but we won't be wearing it.
Will let you know...
DISCLAIMER: This is not to encourage anyone to modify their windshield, just to let you know that it can be done, with a couple of tools.
