Metro aerodynamics

[krousdb]

Awesome Metro! Cant wait for the results.

[MetroMPG]

cardboard rear undertray

[MetroMPG]

well, screwed up the

[MetroMPG]

in hindsight, i should have just re-attached the rear tray and done another run before pulling them all off.

to be honest, it didn't occur to me that it might have been hanging down the whole time affecting all the undertray runs until after i had removed them all.

big, self-administered dope-slap

[SVOboy]

Don't worry yourself too much, you have proven to use that coroplast is the stuff to use,

[krousdb]

Originally Posted by MetroMPG

i did 2 bi-dir "naked" runs for comparison, which produced very similar numbers:.

Isn't "streaking" illegal up yonder? Even if it isn't, it's a bit cold outside to run naked, isn't it?

I'm hoping that your tray was hanging the whole time. I had a 57 MPG bi-directional run at 55 ave speed, and that was with my spare 4th cylinder along for the ride.

It was 25F warmer outside though and I was using constant throttle, bleeding off speed uphill and gaining speed downhill. Hmmm. Maybe not a fair comparison to holding 55.

[XFi]

Just got back from picking up my Coroplast!!! I'm excited 'cause I only paid $9.25 for each 4x8 sheet. The real kicker is that the vinyl supply company I purchased it from has multiple colors available. White, Off-White, Green, Yellow, etc. I got it in black so I wouldn't have to deal with painting it. Yeah, no overspray...not that it would matter, the paint on my car is pretty much 'dead' anyway. Going to check the weather for tommorow (day off), maybe get it done.

***What kind of hardware/screws did everyone use for installation? Just self tappers or did you drill holes?***

[krousdb]

Self tappiung screws with predrilled holes when screwing into plastic or steel. Use washers to keep the head from pulling through. For coroplast to coroplast I used coarse thread drywall screws. They hold the coroplast well. After a week my coroplast is secure. Nothing has losened up.

[XFi]

Just completed cutting and fitting my rear tray. Thought I would start in back where the panel is smaller so I get used to working with the coroplast. Am planning on tucking the panel up above my rear bumper lip (nice and clean), but I need to get some different hardware 1st.

My question for anyone/everyone is...would it benefit the aerodynamics of the vehicle if I attached it under the rear bumper cover and let some stick out the back? I'm not worried about the looks of the vehicle, so if it had a 3" lip of coroplast sticking out the back would this direct the airflow more efficiently? Lower the drag? Thoughts?...

[n0rt0npr0]

not that I know much but that seems very streamlined. I think thats a beneficial aero way to do it. Deleting that lower bumper lip like you describe with the overlap, I think thats a great idea.