I'm glad you like it. Yes, learn from my mistake and get a wing first.

It is riveted to the bumper skin, and then the lower part of the skin was cut off. This gives me a lot more room in there for brake and radiator ducting and saves a bit of weight. The rivets don't have any backing but they aren't quite strong enough, a couple of the more stressed rivets pop out occasionally. I'd recommend backing them with rivet washers. I'm gonna add some washers myself next time they pop out.

The hardest part is getting the air dam cut right. It looks like its a perfect rectangle, but its not. I used the recessed line in the bumper skin as a guide and cut the dam to follow it. I found that a jig-saw worked well for cutting the ABS, a sawzall would probably work too. The hard part is to keep it from melting as you cut it, keep your cutting speeds low and be patient. Of course, a cardboard mock up is crucial.

Good luck, and feel free to ask here or shoot me a PM with any other questions.

Thanks for the suggestions. ;)

Just faeflora it. :fawk:

Gotta get a right angle and everything cut before you put it on assuming you want it perfectly straight, if u want an angle, then it would have to be an arc kind of a shape.

+1 on all of it. I did the same thing and this all matches my experience. Also do yourself a favor and buy one of these:

http://www.harborfreight.com/heavy-d...tle-66422.html
https://www.miataturbo.net/attachmen...ine=1339525643

I went to sandown raceway with the fastback on, and it was raining on and off all day, so i didn't get any consisitant data. My top speed was 186km/h, best previous on a full dry track was 180km/h. There are 3 changes i made, pod filter, vented hood and fastback. I was going to remove things to see where the speed came from. But the weather was crap.

This is a mock up of the windows. Should be starting on the full fastback soon.

https://www.miataturbo.net/attachmen...ine=1339584864

goddamn it, that's awesome. move to Miami, let's go into business. I'll bring the hoes.

Here's a pic of the monster splitter from blytheville w/ my tiny wing. Support is just 1/8" cable running looped through splitter that attach to eye bolts added to the bumper.

Dollars spent: Material, ~$100, labor ~300
Hours spent: Many
How effective: 2 compared to previous composite (ISC Racing) airdam
0=slower, 1, no improvement, 2 =slightly better,3= big improvement
Materials used:
Econolite 2-piece splitter, PVC air dam, Dzus 1/4 turn fasteners, aluminum sheet supports, pop rivets
Size/thickness of materials:

• 1/4" 2-piece splitter extends to rear of front sub frame.
• Splitter is split along center line of vehicle and held together with bracket & 1/4 turn fastners. Allows easy transport and easy(ier) repair.
• Held to front bumper with 1/4 turn fastners, supported in the rear with 2 aluminum hooks which slide over pins/brackets welded to the subframe.
• Top of air dam is attached to oem bumper cover with 1/4 turn fasteners.
• Front center of air dam is attached to aluminum flange/grill which houses grill and brake ducts and which is solidly mounted to the bumper structure.
• Bottom of air dam is attached to splitter via 1/4 turn fasteners through aluminum L-shaped bracket attached to the splitter.

Tracks tested on: New Hampshire Motor Speedway, South Oval config
Race/TT class built for: COMSCC SPC
Result: 1:12.511, class record

No, that is not me in the pic. :)

https://www.miataturbo.net/attachmen...5&d=1339616803

can we please see a detailed pic of the dzus fasteners?

did you cut the bottom off of your factory bumper?

I don't have any detailed pics of the dzus, but will take some.

Most of the bottom 1/2 of my bumper was removed by a gravel trap at Summit Point raceway. :rofl: But to answer your question, yes, the remaining part of the bumper was trimmed about 4" below the body crease.

idk if I wanna cut my current bumper (it's freshly painted) : - |

That almost has a 911 look about it-you just need a whale tail.

Splitter done:
https://www.miataturbo.net/attachmen...5&d=1339664826
https://www.miataturbo.net/attachmen...6&d=1339664826
https://www.miataturbo.net/attachmen...8&d=1339664871
https://www.miataturbo.net/attachmen...1&d=1339665148
https://www.miataturbo.net/attachmen...1&d=1339665148

What's it weigh? It looks beefy.

Wildo, could you post some pics or just a more detailed description of the rear bracket/pin mounting setup you're using? That sounds like a good idea, as my current "long bolts going into the subframe" method is a PIA to remove/install.

Also, how reliable are those Dzus fasteners for you? Do you use any particular type that are better than others? I remember them being extremely unreliable when I used to road race motorcycles... we always had to put duct-tape over them to keep them from coming undone.

What do you guys do about the sides? Just let it open or what?

I'm referring to the area behind the wheel... the stock plastic panel covers the sides too (around the antisway bar)

If you replace that do u fill it with anything or do u just leave it open?

Poplar plywood is _very_ light. I can hold it up clamped between two fingers.

Hmm. I dont know if we can get poplar plywood in the states. At least, I dont think we can get it easily around here.

i would block it off.

Try Meranti/Luan. It is a marine grade plywood. Very light as well