DIY Thermoformed Polycarbonate Door Windows

With the NASCAR style doorbars of the cage and me not thinking far enough ahead I have to run bolted in polycarbonate (PC)/lexan/makrolon…it’s all the same… door windows. Unfortunately the door bars stick a little too far in for me to keep the rails to roll the windows up and down. 

Looking online at various places I realized people want an arm and a leg for these things; around $500 after it’s all said and done. Having access to a large oven and some free PC drop material I decided to make myself a set to save some money. Note that large box stores sell PC sheet for a decent price if you have to purchase some and for a miata you'll have plenty of material for a couple sets.

Below is a rough outline of the steps taken to form, trim, and fit the PC door windows. 

PC scratches VERY easily and is a pain in the ass to polish out. Keep the protective film on there for as long as possible and reuse it when not forming or when you're trimming to size post forming. 

Using your CLEANED OEM glass as a mold, place the PC onto the glass and clamp to the bottom edge of the glass. Protective film of course needs to be removed for this. PC piece should be a little larger than glass size.

Set the clamped glass and PC in an over and support in a way that allows the PC to “fall” onto the glass without obstruction. The forming temp of PC is 300-500 deg F depending on supplier, thickness, desired shape.. start low and see how it looks before increasing temperature. For these it was 310F for 5ish minutes. 

once the PC forms to the glass, turn the oven off and let it cool. Once cooled, remove the PC/glass making sure to not shift anything. Using a sharpie, trace the glass outline on the PC. I then removed the glass and reapplied some protective paper to the PC. After BOTH sides have been re-papered, place the glass back onto the PC and line up with the sharpie marks. Re trace the glass and mark onto the paper with sharpie. 

Cut the PC to shape using a jigsaw or band saw. Use a sander and smooth out/roll the edges. 

Install into the car and match drill as required. Install with longish bolts and an assortment of nuts so you can "push" the bottom of the window out and create a good seal at the trim. I also added a strap that attaches to the door and the top of the window to "pull" the window in to get a better seal.

 

  

 

 

NA and FC Initial Shakedown(s)

Alec and I finally got back on track after a year or so hiatus. We got invited to a private day at Cams Acres Racing Site (Website) before either one was ready, so this was a huge motivator to make things happen. Without the invite I don't think either of us would have been driving our cars this year, so shouts out Tristan (Brown ITB PP FC) for reaching out!

Glad/proud to say that both cars did fantastic with zero mechanical issues. We had low expectations on our driving and just wanted to have fun and learn the cars. Drifting is sick. 

Miata Exhaust

Three or so months ago I trailered the k24 miata to Dales shop and built a custom 3” stainless steel exhaust. It’s not perfect, but it’s tucked up well, serviceable, and sounds pretty fucking good in my opinion. Some info/detail shots from the build and a finished sound clip below. Oh yeah, The car’s been basically done minus an alignment, RDX injectors, and a tune for a few weeks.

The exhaust has a “full/street” setup with a vibrant muffler and a turn down tip going out the back and then what I guess could be called a “track” setup without a muffler and just a turndown after the rear subframe. I doubt I’ll ever run the track setup, but it takes no time to remove the “axleback” and swap in the little turndown that I can just keep in my toolbox. 

 

Miata Bash Bars

 Been a while since I’ve updated this. I’ll try to actually make some posts catching everything up for the time gap but no promises.

For the most recent update, Bash bars! 

The OG miata never had bashbars…not even OEM… and it always made minor fender benders a huge headache. These should allow some smaller hits here and there without the need of pulling the chassis back to install panels. The front is  ZerekFab upper and lower bash bars that fit behind the factory bumper nice and snug. For the Rear I picked up a used TrueFocusFab a while ago. It came without a jack point but added one. I’ll shoot a photo next time I pull the bumper off. 

This and That

I've been slacking on updating this and have been meaning to make a Bullshittin' In The Backyard 3 post... I'll get to it eventually. In the mean-time here's a quick random collection of photos from the last 6 months or so. Hover over the images for descriptions. 

Miata Cage Timeline 1

I've been slowly chipping away at caging the new Miata chassis; working a few hours at a time after work maybe once or twice month. I'm fitting the cage and tacking it in but having Dale burn it in because I don't trust my welds enough and because his will look better.  I'm extremely grateful that Dale has gave me full access to the shop and his tools; I can't thank him enough. Working around my free time and Dales has been challenging to say the least, but he's okay with it sitting in the shop, and I still have the other Miata for seat time. 

The interior has been stitch welded in all the important areas, the driver side floor and the Destroy or Die brackets have been modified/massaged to fit the bucket seat. I recommend buying a flat bottom seat if you want a plug and play bucket with these brackets, but I'm still glad I went with the seat I did. Most of the front half of the caged is fit and tacked in, just need to finish the driver side door bars and get the anti-intrusion bars mocked up. Hoping to get the cage completely fitted and welded in by the end of June. After that I will be painting the interior and engine bay, then trailering the car home wo start Engine stuff. KMiata swap stuff should be arriving later this month.

I didn't take photos of every step, but you'll get the idea. Hover over the images for descriptions. I've referenced Tom Hamptons blog (LINK) a bunch as it's been the best resource for photos of the installation process of the Advanced Autosports Spec Miata cage. Not a fan of some of the things he decided to do, but either way it's a solid resource and a fun read.