Starting to aero the Subie.

[edbso]

This is what I like to keep air out from under the car.

[pawilkes]

I have been tweaking w/ my Outback, hoping to do a bit more in the future. How are the wheel skirts working? notice any improvement? Do they hold up on rough-ish roads? I want to make a camback for mine this summer when I get some time. it'd be great to hear what works for you b/c it would save me wasting time trying the same things if they don't work.

[pawilkes]

1

[aerohead]

If you looked at my post on "nose-jobs" you may have picked up on the notion that Subaru is no newcomer when it comes to aero.In fact there development model for the XT,back in the 80s scored Cd0.088 in the windtunnel.From a look at the picture of your car I really can't find much fault for the production front end.If I were gonna mod it,I'd do nothing to encourage air from going under,I'd try to channel it to the sides,as mentioned by others.I'd consider a complete upper grille-block and leave the lower intact.That one could be progressively blocked 'til you scare yourself,then back off a bit.The Lexus/Highlander nose has nothing to it's advantage other than the promise of scaling really steep grades.There could be room for a very shallow chin spoiler.It's hard to tell from the photo.A semi-circular nose,when viewed from overhead the car is ideal,however the generous radii,as already present in the production nose provides most of the efficiency as proven 22-years ago by Hucho and his team during development of the VW Scirrocco,Golf,Rabbit,etc..I'm not going to tell you that you're wasting your time on the front end,however your greatest challenge will be at the vehicle rear.If you'll read my installment on "rooflines" you'll get a sense of what I'm talking about.I'll be posting more installments for "undersides","wheels/tires","tails",and some case-studies,you may find info of value to your project.Good luck with the project.

[brucey]

Heres what I came up with.



It follows the bumper pretty much straight down. I'm not worried about overheating, I drove up a 5% grade at 80 mph in 90 degree weather with the AC on full and it didnt move.

The 'dam' goes to about an inch below the lowest part of the vehicle, and I've still got a decent amount of ground clearance and managable approach angle. The worst that can happen is I lose some time, all the materials have been free.

I wish I had a scan gauge or some way to test this.

[SuperTrooper]

Originally Posted by kafer65

I have an 04 Highlander which is essentially the same thing as the Lexus. They are very stable at highway speeds even with the wedgy front end. I looked at the hybrid version and its identicle to mine except for some little front tire air dams to aero the front wheel a bit. I just got 24.8mpg staying around 75mph for about 385 miles and pumped up tires with a 3.o Liter V-6. Our 2k Suby outback got 26. IMHO a great deal of highway mileage could be had with shorter differential gearing. The 76 Plymouth Feather Duster could get 30mpg with a carb'd 3.7 Liter engine because it was light and had a 2.7 something ratio diff.

Dude, you could start by just slowing down.

[brucey]

He's got a point about the gearing. With a 4.44 final drive, It's got some torque for a 160 HP 2 ton car, but at the same time, its revving an engine that doesen't need to be revved to make cruising speed.

I wonder how hard it would be to get a 3.9 in there.

[Shawn D.]

Originally Posted by brucey

He's got a point about the gearing. With a 4.44 final drive, It's got some torque for a 160 HP 2 ton car, but at the same time, its revving an engine that doesen't need to be revved to make cruising speed.

I wonder how hard it would be to get a 3.9 in there.

Well, even if different gearing were available, it wouldn't be "a" 3.9, it would be two 3.9s, given that Subarus have two final drives.

[brucey]

yup.

I'd definately have to crack open the transmission AND replace the rear end.

[Cd]

I'm sure I'm not the only one here that would like to see some pictures of your car when the sun is still out.
Why the dark pictures ?