Aerodynamic question

[morkable]

I have removed the floor of my box, and plan on removing as much of the insides and still be able to support the box sides. If I just run it open like that do you think it will hinder aerodynamics? I hate the thought of closing it in as my tranny coolers are back there and the stacks too.

[RJM06590]

Why no cut the whole floor out and replace it with 1/16 aluminum diamond plate? Not sure how much weight it would shed or if it would be worth the hassle though.

[TMONEYDIESEL]

Cause diamond plate is ugly :hehe: Dont do it Kev.

[SKYNYRD]

closing in the top of the bed would help reduce the drag on the truck but if you cut out the bottom and close int he tail gate it will cause drag as well.

there was a truck that the guy diamond plated between the rails and made fenders for just the tire and eliminated the bed entirely. i'm sure that would shave some weight.

[morkable]

I have already eliminated the floor of the box. I dont usually race with the tailgate on anyways, so there is just a little strip of beam right at the back of the box that holds the box on the frame.

On the diamond plate,,,, not quite my style,, but would work for others I am sure

[Chris Tobin]

If you are going for weight reduction but want to retain the look of the truck, I suggest you go with a set of fiberglass bedsides like used by off road racers... The Bully Dog Dodge uses ones that I think are from FiberWerx. I will be using the FiberWerx bedsides on my project truck as well, but for now I am keeping the box... I want to keep the bed usable while I still daily drive the truck... If it goes to a full race truck at some point I'll ditch the box and support the bedsides with struts to the frame/rollcage and Dzus fasteners...

[morkable]

Chris, have you ever checked out the weight difference between the fiberglass and the regular tin sides? The reason I ask this is that I have found some fiberglass stuff weighs just as much if not more than the origional tin (in hoods I have seen this a lot)

[mondtster]

Chris, have you ever checked out the weight difference between the fiberglass and the regular tin sides? The reason I ask this is that I have found some fiberglass stuff weighs just as much if not more than the origional tin (in hoods I have seen this a lot)

That's what I was thinking, I doubt there will be much weight savings with the 'glass.

[Chris Tobin]

The shipping weight of a pair of bedsides and the FiberWerx 1-piece front end (hood with integrated fenders and fender extensions) with the 2x3 wood shipping crate weighed less than 100 lbs... so I'd say yes it was lighter... I would guess that the steel hood weighs something similar to that... I haven't scaled any of it yet so I don't know for sure but that is my guess.

For a hood it would depend if it had internal structure or not...

[Billy Stocklin]

fiberglass bolt on hoods are always heavy. They have so much internal structure to keep them from breading apart that they offset the weight savings of the fiberglass. They are intended to look cool and maybe shed a few lb's if you can. Bedsides/ doors/ etc etc are intended from the get go to be race pieces for the sole intent of saving weight and therefore will be considerably lighter than their factory counterparts.

[jlibert]

here's a pretty good vid with some explanation...

http://www.youtube.com/watch?v=g_3xnVzf0EE

[dvst8r]

Kev, my 2c the stacks probably weigh as much as the floor you just cut out... Just saying.

[DIESEL_POWER]

Kevin taking advise from guys who have never had a fast vehicle or ever worked with aerodynamics is like sucking on a lolly pop off of the bathroom floor... looks good till you try it.


If you understand fluid dynamics your pretty close, Lighter, smoother and progressive angularity/bends will make for good aero's.


Diamond plate, for the floor, bad idea, the intering sunlight will blind you!
plus a little moisture and it's like glass, with teeth.

You would be better off useing regular aluminum or thin steel and applieing adhesive backed sandpaper strips to the upper surface. unless you will never be back there. Dont forget your bracing!


*the least amount of air under the car the better upper areo's are*

[SHughes]

For what you're doing just leave the bed as you have it. Gutted and open. maybe go to a single stack for a little more weight reduction.

Wade is correct in implying you need less air under the truck to begin with. A larger front airdam to keep air from getting under the truck in the first place should be your next step. And there will still be plenty of air for the tranny coolers.

[Billy Stocklin]

I'll take your word for it on the licking bathroom floors deal. Sounds like you really know your stuff.

Lighter? weight has nothing to do with aerodynamics, drag coefficient, downforce, lift or any of that.

Why would you say that the people posting here have never had a fast vehicle or worked with aerodynamics? Just because you don't know us, doesn't mean we don't know what we are talking about.

The most important things you can do for aerodynamics in a truck is minimize frontal area (slam it in the weeds) and give it a slight rake- lower in the front. Put a cover over the bed. Don't worry about the underside- although a lower level would help signifigantly with aerodynamics. Block off the grill to reduce high pressure under the hood area (picking up front at speed- both decreasing driveability and increading frontal area and coefficient of drag) or at least build an air damn that goes down as far as you feel comfortable. The lower the better- the rules say 3"- but that's pretty low for a diesel truck with a bunch of front suspension travel (read- lots of fixing smashed stuff- but 5 or 6 inches should be ok). Get rid of protrusions- mirrors, stacks, antennas, whatever- chunk it. Keep the tires tucked under the truck.

Kevin taking advise from guys who have never had a fast vehicle or ever worked with aerodynamics is like sucking on a lolly pop off of the bathroom floor... looks good till you try it.


If you understand fluid dynamics your pretty close, Lighter, smoother and progressive angularity/bends will make for good aero's.


Diamond plate, for the floor, bad idea, the intering sunlight will blind you!
plus a little moisture and it's like glass, with teeth.

You would be better off useing regular aluminum or thin steel and applieing adhesive backed sandpaper strips to the upper surface. unless you will never be back there. Dont forget your bracing!


*the least amount of air under the car the better upper areo's are*

[DIESEL_POWER]

I'll take your word for it on the licking bathroom floors deal. Sounds like you really know your stuff.

Lighter? weight has nothing to do with aerodynamics, drag coefficient, downforce, lift or any of that.

Why would you say that the people posting here have never had a fast vehicle or worked with aerodynamics? Just because you don't know us, doesn't mean we don't know what we are talking about.

The most important things you can do for aerodynamics in a truck is minimize frontal area (slam it in the weeds) and give it a slight rake- lower in the front. Put a cover over the bed. Don't worry about the underside- although a lower level would help signifigantly with aerodynamics. Block off the grill to reduce high pressure under the hood area (picking up front at speed- both decreasing driveability and increading frontal area and coefficient of drag) or at least build an air damn that goes down as far as you feel comfortable. The lower the better- the rules say 3"- but that's pretty low for a diesel truck with a bunch of front suspension travel (read- lots of fixing smashed stuff- but 5 or 6 inches should be ok). Get rid of protrusions- mirrors, stacks, antennas, whatever- chunk it. Keep the tires tucked under the truck.

it wasent directed at any one person, just a heads up for kevin. advise is great, but one must weed out the bad from the good, thats all.

[TravisG]

it wasent directed at any one person, just a heads up for kevin. advise is great, but one must weed out the bad from the good, thats all.

Either way you posted it after he did. If that's Billy Stocklin from Texas, then I can assure you that he goes fast.

[Timbeaux]

Either way you posted it after he did. If that's Billy Stocklin from Texas, then I can assure you that he goes fast.


Perhaps?????

http://www.youtube.com/watch?v=iyFz5luqTIk

[wideopen]

What's that? Wade sticking his foot in his Mouth......Not possible.


http://blogs.seattleweekly.com/dailyweekly/foot%20in%20mouth.jpeg


Or is it?

[UNBROKEN]

Billy's toenail clippings know more about going fast than Wade will possibly ever know.
Learn how to pick your battles Wade...Billy is in the big leagues...you're still playing t-ball.

[TMONEYDIESEL]

Batting practice starts in 30min

[morkable]

Brett, I know that a single stack would be lighter,,, but I just cant do it,, lol,, I need to lose weight somewheres else,, just cant do a single, dont like the way it looks... lol

[dvst8r]

Brett, I know that a single stack would be lighter,,, but I just cant do it,, lol,, I need to lose weight somewheres else,, just cant do a single, dont like the way it looks... lol

No stack, just an aluminum down pipe out the fender... :st:

[THATpreston]

No stack, just an aluminum down pipe out the fender... :st:

Just as long as the smoke can't interfere with the staging lights....

[dvst8r]

Just as long as the smoke can't interfere with the staging lights....

Bull horn. Like the 275x guys.

[Runninlean]

Just as long as the smoke can't interfere with the staging lights....

Not according to NADM they want it pointing upwards.

[TMONEYDIESEL]

Not according to NADM they want it pointing upwards.

So make the downpipe turn up,

[dvst8r]

Not according to NADM they want it pointing upwards.

See the bull horn comment above. :shake:

[Runninlean]

Yeah my comment was not in response to your post it was referring to Preston's.

[Billy Stocklin]

Billy's toenail clippings know more about going fast than Wade will possibly ever know.
Learn how to pick your battles Wade...Billy is in the big leagues...you're still playing t-ball.

I'll trade you some clippings for a smoke switch schematic! LOL- thanks for the kind words guys. I have not seen that video before. Thanks for the link. That was a good day.

[Louis]

What kind of speeds? Aero is a totally new thing, and it behaves very abnormally. I've logged about 40 hours in wind tunnels the last 5 years and do a lot of CFD work. Maybe I'll whip something up.

[morkable]

I hope to be around 140 mph in the 1/4

[roachie]

The shipping weight of a pair of bedsides and the FiberWerx 1-piece front end (hood with integrated fenders and fender extensions) with the 2x3 wood shipping crate weighed less than 100 lbs... so I'd say yes it was lighter... I would guess that the steel hood weighs something similar to that... I haven't scaled any of it yet so I don't know for sure but that is my guess.

For a hood it would depend if it had internal structure or not...

From memory you were dealing with a chevy? They use old school construction that uses enough steel to allow glass to be lighter. In dodge and ford apps the glass weighs more than the tin.


Kevin, I would have just bought some bed skins from dodge and made aluminum supports to hold them in thier respective places. The skins weigh about 30-40lbs.

[Runninlean]

Mine is cutout to the bed skins and I run a cover. Now that im thinking about it might pull the keeper pin's off the gate and see how bad the rear section lifts going down the track. (not a wide open pass of course build up to it)