Rear diffuser experiment

[Cani Lupine]

On my last car ('96 Ford Aspire), I was able to make a halfway decent rear diffuser, but with how short the back end is on this car, it's more of a challenge. The underside is pretty open, and the evap canister hangs pretty low under the spare tire well. After I reclaimed a sheet of coroplast I had in front of a broken gas fireplace to keep the draft out, the bug bit me and I decided to see what I could do.

I started with a vertical piece behind the rear axle to prevent air from getting on top of the diffuser and pulling it down. I trimmed it to fit around the hoses that were up there and zip tied the piece to one of several small metal pipes that run under the car.

The main panel was attached to the front plate with Gorilla tape on the inside and outside, trimmed to fit around the tailpipe and tow hook, and tucked up underneath the rear bumper lip. Gorilla tape was used to secure the panel to the rear bumper, so everything is fully reversible.

It actually sits slightly lower than I thought it would, sticking out about an inch past the torsion beam and about level with the spring seats, but then again, it is lowered a bit. I can't lift it any higher because of the evap canister, but I could trim the front plate some and give it more of an inverted wing shape. We'll see if it works!

I'll be adding fences on the extreme ends of the diffuser later, since I ran out of both coroplast and Gorilla tape by the time it came to this stage.

UPDATE: Picked up some more Gorilla tape and added some extra strakes this evening. I had JUST enough coroplast left over to make four, for a total of six. Took it out on a drive with my roommate today to a wildlife reserve, but it was pretty windy, so I can't comment on the effectiveness yet.

[Daox]

How is this working out? Have you noticed any benefits from it?

[Cani Lupine]

Butt dyno wants to say it coasts a little better now, but I can't really gauge how much improvement since I haven't done any A-B-A testing. I did get about a 60 MPG average today on a 45 minute freeway trip with some traffic and minimal red lights, so it does seem to help.

[HitShane]

Now just make a mold of your prototype that bolts on easy to factory mounts and sign me up for one. Take my money. If you can color code them to factory paint colors then charge double...

[MightyMirageMpg]

Cool experiment. Looks like you did a nice job boxing in the sides preventing parachuting. any pictures from behind the car? Your all about that gorilla tape lol