Ryan, I kept up with your build on the other site, the underbody you are mounting was aluminum, is that correct?

Excellent. thanks for everyone's help.

Ok aluminium it is. ill get some X shaped creases put in it like air con ducting for rigidity.
what's a weld nut? do they mount flush? rivets make this whole job just- drill. rivet. bolt. very straight forward.


Lighyear are you suggesting to make an alloy plate that is wider than the body is?

thanks,
Dann

I think that he's suggesting something like this:

https://www.miataturbo.net/attachmen...ine=1356824868

You'll want to minimize the amount of air being sucked under the car from down off of the sides.

- Tom

I'm planning a V8 Supercar style side-skirts, flat panelled from suide to side, of course that brings thread back to jacking points ;)

What if you had some sort of easy access release for the underside bolts for SS and used low profile ramps to get to them. I'm not as experienced as you fellows, but that has just been my thoughts watching Ryan's build and thinking up my own aero pieces.

The diffuser I made is all aluminum. The first flat underbody I made was 1/8" ABS. It held for 250 miles round trip on the road and a full track day at ACS, but it has warped, so I am now making version 2 out of aluminum - no plastics that can warp from heat.

-Ryan

Dann, weld-nuts can be found here (they also sell good quality riv nuts):

McMaster-Carr

Riv nuts are not the same as regular rivets, not sure if you've looked them up, but they require a special tool (different than a rivet tool) and specific inserts for the particular size thread you're doing, and most of those tools are $50+, so if you have a welder at your disposal, weld nuts can save you money. Plus, like I said, weld nuts are more reliable.

-Ryan

I've used dezus fasteners on 2 cars, If you do them right, they're awesome go in easy, never come undone by accident. If you're sloppy, lazy on the install, or dont have the right length 1/4 turn part they suck because you can never get them in or they dont stay. I like to tape them for extra safety because we have had the main body have two of the 3 dezus that hold it on come un-done from cone strikes before on the car that was done sloppily.

fiberglass on splitters, I like giving them a light coat of the cheap polyester resin, but no glass mat, on all sides and edges to prevent it from absorbing water and warping. Its a bit tough though to get it on without making the spiltter heavy, wood likes to soak up the resin. I wonder if the resin will stick to primer.

As for lifting points when larger side skirts and flat under tray installed I would look to the rally world and use the pin stand method. Just build an adapter to sit in the pin socket to jack from. This will also allow a full width under tray.

^^^ I was going to suggest something similar. All you need is a hard point that penetrates through the undertray and transfers load to the rocker box jack points, or the frame rails. Hell a 1" dia thick wall steel pipe (hardware store) cut to length and stitch welded in place would do it.

I am talking about jacking straight-up from under the car. You will need a low profile jack for race ride heights. Pin jacks coming in from the sides (like a E36 BMW M3) or like mentioned above would do the trick as well. That will take more welding than what I described above.

Or go full baller and have built-in air jacks.

This thread continues to make me want to do things to my car that reduce its street driveability. Since such things can't really occur, I am conflicted. Attempting conflict resolution via beer ingestion.

Good plan on the beer. Works for me.

Drink the beer, then go back and make the irrational decisions.

Has anyone here attempted the pin jacks before? There's no way in hell I can get the front end in the air without taking half the nose off the car. I'd like to do it to my RX7, but can't visualize how to do them without having them protruding below the rockers.

How about welding FM jack adapter plates (or something similar you build yourself) in place on the car and build your undertray/skirt around them?

https://www.miataturbo.net/attachmen...ine=1356968478

Looks like it would work well except for those of us with these damned side skirts...

You just have to cut a slot either side of the pinch weld in whatever skirt you have there.

Dann

Im getting started on my project in the next couple of days, ill post updates.

Dann

Updates and pics - than they better not be upside down ;)

I'm cleaning the increased air pressure in the rear wheel wells. Still have to customize the rear bumper

https://www.miataturbo.net/attachmen...ine=1357007662

https://www.miataturbo.net/attachmen...ine=1357007662

https://www.miataturbo.net/attachmen...ine=1357007662

https://www.miataturbo.net/attachmen...ine=1357007662

https://www.miataturbo.net/attachmen...ine=1357007662

https://www.miataturbo.net/attachmen...ine=1357007662

https://www.miataturbo.net/attachmen...ine=1357007662

https://www.miataturbo.net/attachmen...ine=1357007662

Great idea, RJ. Did you do the same for the middle of the trunk?