Rear diffuser
 

just finished building and installing... 1/16 alluminium sheet with 3/4 square tube frame. next is flat bottom panels and the underside aero will be complete.

Kris.

total weight? Wool tuft tested? force gauge tested?

Dann

Can you hit it with a hammer and make a cheesecake?

Wind tunnel results?

Does it give the boner sauce?

Despite your lack of scientific cockmongering I think it looks great.

total weight less than the spare tire.

and im no engineer so no wind tunnel, but as soon as i get some rain here will get some highway spray tests done. see if it directs any air flow.

Kris.

Are you racing the car ?

if it weighs even half as much as the spare it's way too heavy. it's easy to overbuild the mounts for the diffuser. can't remember the thickness of mine but it only weighs about 6lbs. and it's been abused for almost 3yrs. 3.5-5* seems to be the sweet spot on the diffuser angle. too much and the air detaches from the diffuser. too little and there is no effect. use tufts of yarn and follow behind in another car at highway speeds, or do what i did and use a go pro camera and film different angles. if it's just for looks, you're already there, looks great.

I read somewhere when a guy was testing aero mods he'd get some oil on them and hit the highway and check out the trails it left to make adjustments.

Food for thought, might be easier to work out than a rainy day?

spoolin, i definatly over built the frame work but im not worried about a couple lbs. and the wool tuft thing is the way to go for sure just need to find time to get out there. once i do i will post some pics.

Kris.

looks good!

I need one of these!!!!!

ive done a good amount of research on this and bookmarked some links i think may help. Hope it helps.

http://forum.miata.net/vb/showthread...=212145&page=2
http://forum.miata.net/vb/showthread...89#post2671589

These two links rock!
http://www.modified.com/tech/0607_sc.../diagrams.html
http://www.modified.com/tech/0610scc...t_2/index.html

http://www.nittotire.com/blog.asp

now dont go stealing all my ideas!!!!

My feedback
-Ditch the bolts and weld it (or rivet it) to the frame
-You need fences on the ends
-Can't tell the angle but you should be cutting up into the bumper I would assume
-Get rid of all the cutouts unless they're absolutely necessary

Not a bad first effort though and way better than what I have right now (nothing ;))

My feedback
-Ditch the bolts and weld it (or rivet it) to the frame. no way. i would want it removable. 4 bolts hold mine on, few minutes puts it on or takes it off.
-You need fences on the ends - yes
-Can't tell the angle but you should be cutting up into the bumper I would assume. you assume wrong. it's most likely in the right range. if he wanted it to "look" cooler, he could cut the bumper and curve the very end of it up without hurting the function-
Get rid of all the cutouts unless they're absolutely necessary

Not a bad first effort though and way better than what I have right now (nothing ;)

I meant between the frame for the diffuser and the diffuser itself. Take a look at his picture... there's like 20 bolts that don't need to be there.
I'll take a look tomorrow at what the angle would be. Just glancing at it though the angle looks pretty tame (but the pictures aren't the greatest for judging that).

what kind of diffuser should I attach to my car's ass?

https://www.miataturbo.net/attachmen...ine=1312525245

Yes, I value function over form regardless of what the trunklid may lead you to believe.

i would run a lotus elise/exige style diffuser, where the two outside channels are higher than the inner one. for the diffuser to work properly, you need to have the leading edge be curved or curve into the rest of the diffuser. simply a sharp angle will result in separation of air.