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Wrench · 06-14-2011, 07:40 PM

@ Otto: That crossmember with all the holes in it is the rear axle. Saturn ditched the nice (expensive) independent rear suspension for a crappy (cheap) solid axle design when they dropped the SL cars and went to the ION. I don't see a very good way to attach a pan to a live axle.

To the OP: I've been looking into aero-modding my 2004 ION, aiming for 40 MPG highway (best tank 35.5 MPG, 72 MPH cruise, stupid 10% ethanol Minnesota gas).

From my quick and dirty testing as well as the road grime buildup on the car I think the biggest gains are to be had in the rear. As my tuft-testing (somewhat) shows there is a significant stagnant area on the rear window that can be easily seen every time it rains or snows (droplets sit motionless in the middle of the rear window and snow will actually swirl around the center of the rear window at 70 MPH for many miles.

As I'm sure you've noticed, the trunks of these cars gets TONS of road grime and tar stuck to them which made me think the car is dragging a huge wake. The wake theory was proved (to me anyway) the time I had an 18" boat-tail mod on the car (snow buildup hanging off the vertical part of the trunk) from driving 5 hours in a blizzard... I had to remove it so I could open the trunk, but it would have melted in a couple days anyway.

I intend to tidy-up the rear bumper area similarly to how you did it as well as experiment with vortex generators at the back of the roof/top of the rear window. Maybe an upper grille block thrown in for good measure.

-Wrench

(Guess I can't add attachments, probably because it's my first post. I'll come back and add them when I'm allowed to.)

06-14-2011, 07:40 PM	#47 (permalink)
Wrench EcoModding Lurker Join Date: Jun 2011 Location: Minnesnowta Posts: 2 Thanks: 0 Thanked 0 Times in 0 Posts	Necro-thread revival @ Otto: That crossmember with all the holes in it is the rear axle. Saturn ditched the nice (expensive) independent rear suspension for a crappy (cheap) solid axle design when they dropped the SL cars and went to the ION. I don't see a very good way to attach a pan to a live axle. To the OP: I've been looking into aero-modding my 2004 ION, aiming for 40 MPG highway (best tank 35.5 MPG, 72 MPH cruise, stupid 10% ethanol Minnesota gas). From my quick and dirty testing as well as the road grime buildup on the car I think the biggest gains are to be had in the rear. As my tuft-testing (somewhat) shows there is a significant stagnant area on the rear window that can be easily seen every time it rains or snows (droplets sit motionless in the middle of the rear window and snow will actually swirl around the center of the rear window at 70 MPH for many miles. As I'm sure you've noticed, the trunks of these cars gets TONS of road grime and tar stuck to them which made me think the car is dragging a huge wake. The wake theory was proved (to me anyway) the time I had an 18" boat-tail mod on the car (snow buildup hanging off the vertical part of the trunk) from driving 5 hours in a blizzard... I had to remove it so I could open the trunk, but it would have melted in a couple days anyway. I intend to tidy-up the rear bumper area similarly to how you did it as well as experiment with vortex generators at the back of the roof/top of the rear window. Maybe an upper grille block thrown in for good measure. -Wrench (Guess I can't add attachments, probably because it's my first post. I'll come back and add them when I'm allowed to.)