"Aero" Beast (1989 Grand Wagoneer)

[aerohead]

Originally Posted by jmedia

Hey all,
Loving the site so far for my escort.
But I have another love in my life that is basically a brick on wheels.
My 1989 Grand Wagoneer
She is gonna be my summer project, gonna swap a diesel and a 5 speed into her.
I am curious about working on the aerodynamics, but I know there is not much to work with. I am pretty confused on how to calculate the Cd of my vehicle.
And i was wondering if there is any kind of wind tunnel software I could use

thanks

jmedia,I have a CAR and DRIVER roadtest of the Grand Wagoneer.They published Cd 0.55 for that vehicle.
It's both the worst and best candidate for mods,because it could use it the most.
Look over the stickys here at the forum for mod ideas and potential benefits.
Also,look at modern JEEP products to compare where they went with design.
As far as CFD,whatever you use,it MUST create an accurate portrayal of the wake.This is your biggest challenge after cleaning up the front.

[jmedia]

Holy crap haha that's a pretty high cd. Unfortunately i love the look of my vehicle. And I will have to lift it to put the diesel in it. If it's lifted, will an undertray(I'm not sure what they are called) help out? And I thought chopping the top like my pic and then placing a bed cover over it that was more gradual would help the turbulance behind the truck (even of it left me with a dinky bed)

[DonR]

Sweet Jesus don't cut up a Waggy.

If you're going to lift it & put on bigger tires, use a tire dia. you can get non-flotation sizes in, then swap on the boggers for the trail. Mooneyes & removable wheel well skirts should help some for the street. You will want to remove them for the trail.

You can probably get "skid plates" for most of the underbody & cover the gaps with the material of your choice. You could make an undertray of lesser material, but if you're venturing off the beaten path you'll want the much thicker skid plates.

A Kamm extension (Tapered side panels & roof panel) will help as Jethro suggested. It will also give a clean straight edge for the air to seperate cleanly from. This is why most Crossovers, mini-vans & wagons have that lip on the rear roof.

Are you putting in a Cummins 4BT?

Don

[jmedia]

Haha ya it'd be hard for me to cut up my wag, just cause I'd be scared. I don't offroad tho so that stuff isn't an issue.
I wish I could swap a 4bt in but unfortunately it's illegal in CA so I'm looking for a gm 6.5 td