Underbody streamlining

[yucatec]

Dear Panthers,
Read an interesting article about wind tunnels. Turns out the Ford Flex does pretty well because its front bumper is far enough forward to direct the airflow over the car rather than underneath, which is an airflow nightmare. Might be our boxes are less boxey than we thought. But I have a question: has anyone put a body pan under a GMN engine? Did it reduce fuel consumption, increase power? Donald McCaig

[mrltd]

I don't think anyone has. I've considered an airdam and/or a tray to see how well it works.

[1987cp]

Far enough *forward*? I seriously doubt that a bumper being further forward would have any effect on airflow.

[LTDMan83]

I've thought about trying to fabricate some Body Pans, to cover the undercarriage areas where the airflow would be the most turbulent, like under the engine bay area. Though, I currently don't have access to the tools/machines that I would need to fabricate a piece that would look nice, and be functional. So I probibly won't attempt it anytime soon, but it may be somewhere in the works for my box(es) in the future.

IIRC, the early 90's Towncar's had a plastic Body Pan covering the entire front area under the engine bay. Maybe one could be modified/adapted to fit the Box Body.

[gadget73]

I've also tossed around that idea, it should help with fuel economy somewhat. Underneath of the car is pretty "dirty" as far as airflow goes. If something could be done even from the bumper to the engine crossmember to smooth it out, it should help. The trick is going to be fabricating something solid enough to mount securely, yet is easy to remove and light enough to not negate any gains. It would also need to clear the front suspension pieces.

[torquelover]

IIRC, the early 90's Towncar's had a plastic Body Pan covering the entire front area under the engine bay.

I would like to see this.

[Pesty351]

Far enough *forward*? I seriously doubt that a bumper being further forward would have any effect on airflow.

I don't know how much it would pertain to the slow speeds our cars go, but on the F-15 the first 10"s of the nose cone isn't allowed the slightest imperfection. They say even something like a small pimple with throw off the entire aerodynamics of the jet. I asked one of the pilots about this he said at high AOA/ low speed it could even cause the jet to be uncontrollable and send it into a spin. So with the bumper being the "first 10"s" maybe it could affect the aeros in such a fashion. Maybe?

[CheeseSteakJim]

Far enough *forward*? I seriously doubt that a bumper being further forward would have any effect on airflow.

...why? It makes perfect sense to me.

[yucatec]

Dear Panthers,
Is the 90's towncar narrower than an 89 box? Any nearer size GM products with body pans? Donald McCaig

[1987cp]

...why? It makes perfect sense to me.

Then perhaps you can elucidate!

Not that I have any doubt that the bumper cover's design does contribute to improved aerodynamics, I just don't see how its location fore-to-aft can have much, if any, effect. For example, if I did a Dave84 routine on my front bumper, randomly extending it a foot or two past where it should be, I highly doubt it'd improve the aerodynamics of the car any.

[DuceAnAHalf]

for an air dam it only needs to go as far down as the lowest component under the car. my air dam is pretty big, 36" wide and 5" tall, but its under the radiator and not attached to the front bumper.

i have an idea for a big air dam for the front of the 97

[P72Ford]

Far enough *forward*? I seriously doubt that a bumper being further forward would have any effect on airflow.

Not that I have any doubt that the bumper cover's design does contribute to improved aerodynamics, I just don't see how its location fore-to-aft can have much, if any, effect. For example, if I did a Dave84 routine on my front bumper, randomly extending it a foot or two past where it should be, I highly doubt it'd improve the aerodynamics of the car any.

All he mentioned was moving it forward. Surely he also intended a shape change. Without knowing the shape, there is no way you can comment on the effectiveness of the idea/ design. How important is shape to aero? You should know this...

[gadget73]

Dear Panthers,
Is the 90's towncar narrower than an 89 box? Any nearer size GM products with body pans? Donald McCaig

90s Townie is the same width, though I'm not familier with this pan so I don't know how well it may cover. There is nearly no real difference underneath a 90s model vs an 80s model so I don't see why it would be a big deal to modify one, assuming it will actually do the job.

[p71towny]

With some trimming it "should" fit. Aero GM's have it too. and Im sure the vics do as well.

[CheeseSteakJim]

The underside of my mom's '04 325ci is completely covered up. You wouldn't even know there was an engine up there. You have to remove like three different shrouds just to drain the oil.