Lizzard Belly

[BlizzardX23]

I posted an example pic above...




also, I like this too...its the belly pan of a Maserati..

 

[jomulk56]

Bliz that's a good idea. You might have to create a diffuser for the rear and splitter for the front to reduce resistance.

 

[AquinoSteven]

Its a good idea but the only problem that i think would happen is that if you dont do the whole bottom of the truck, air is going to go up at the first possible chance. If you close off the whole rear, then you got a pocket creating drag. I doubt my theory is right but either way its gonna be cool haha

 

[Eagle]

heres the issue.

you can't do the center. ds clearance

you cant to do the exaust side. heat

you cant do the trans. heat.

you are left covering the already mostly flat underfloor area.

this is why most of the vehicles with nearly flat floors are IRS and have the exhaust stacked under the DS.



n addition if you ever paid attention to other GM products, they don;t hesitate to put a piece of plastic somewhere under the vehicle to direct airflow.
The fact that they did not on the SUV indicates it would be of minimal value, especially after you added 50 lbs or sound absorbing and heat reflective material to it, mounts etc.


Sure air resistance increases as the square of the velocity. (9 times more drag at 90 than 30, 25 times more at 150) BUT:


if your truck is nose down then the underside is mostly a wake zone. minimal drag.
Add the front air dam and you reduce underbelly drag more.
This is why most vehicle manufacturers merely seek to get it 'levelish'. and make the rockers lower. Air won't be actually flowing at 90 mph over the underside... mostly it will be static and air flows over the static boundary layer... much less resistance than air flowing directly over the surface. You could actually ADD drag with your proposed idea



BTW, flat panels have more drag than dimpled ones. same reason ports in heads should never be polished smooth.

 

[thehoe92]

and to add to eagles last line.. look at a golf ball

but if you still want to do it I'm down to help

 

[puckhead]

hmm, interesting idea. I would be more interested in putting up some skid plates. Let us know what you do

 

[highrollin113]

ya i watched mythbusters and they covered a car in clay and cut dimples out so it looked like a giant golf ball, it actually got better milage than the car with the regular body

 

[Tahoewhat]

ya i watched mythbusters and they covered a car in clay and cut dimples out so it looked like a giant golf ball, it actually got better milage than the car with the regular body

I saw that espisode, but started half way through it and had no idea what they were doing, very interesting though..

But bliz, you and the hoe must have alot of time on your hands, wish you guys lived closer, like all the ideas you guys come up with. I say try it and see how it goes. Also, to add to the list, mercedez, bmw have the stuff underside also. The only bad, everytime you have something to do, oil change, exhaust change, suspension ? you have to take all the plastic off.

 

[BlizzardX23]

I know the logic behind golf balls....

and "why GM didnt do it to their SUVs" is 110% irrelevant within this website...

GM didnt lower their SUVs for a reason...GM didnt put limo tint on their SUVs for a reason, and GM didnt provide BB tunes for a reason...

Your definitely the smartest guy on this site when it comes to physics and explanations...I wont argue that...

and guess what...your logic works for your truck...and I'll test my logic on my truck

---------- Post added at 08:13 PM ---------- Previous post was at 08:09 PM ----------

 

[Eagle]

True, but I`m the guy getting 20-21 mpg freeway on a bone stock 5.3l
No tune, funny plugs, lowering, airdam, intakes, e-fans, or underbody trays needed.

why GM didn`t do it is 120% relevant. They spend MILLIONS on wind tunnel testing these sobs looking for an extra 0.5 mpg, & or reduction in NVH.

You are stating that if a tray would make an appreciable difference in drag, and thus improve fuel economy they wouldn't do it? CAFE targets mean they absolutely would.

But you want to do it so... enough discussion.

here is how I`d do it.

1/16th inch aluminum stock welded to a 1" square tube frame. You also need some type of noise dampener and section it off with the tube into sections 3-6 ft2 to avoid large low frequency vibration nodes. run it from flush with the running boards to flush with the running board. post rear axle is un important and ahead of it you interfere with engine bay airflow /cooling.

IF you want to do it, you have GOT to solidly block the front side of the tray so it doesn´t become a big airduct or wing element. That would be MORE drag, not less. you are NOT trying to create downforce here.

you will probably want to do a large naca duct for trans cooling in front of the pan. and another for the exhaust. You will need to create a low pressure zone to induce airflow by using few 1" tall 6-12" wide reverse louver as exhausts.

good luck, and make sure you wield the hell out of your mounting brackets.