GMC Extended Van - Distance between roof racks

[supthecreek]

Installing Weatherguard Aluminum Ladder Racks on my 2001 GMC Savana 3500.

Gutter length is 12' 4"

Heading to Florida with a full van, so need to go to the roof for this trip.

Going to carry 12'er and 14'er.... possibly some 10'6's as well, on the roof racks
I'm thinking leading edge of 14'er near the front edge, maybe trail off the back 2'
or split excess front and back?
Trying to keep windage down on the long haul, at breakneck speeds 

Raceboard expertise appreciated.

My thoughts

3' back from windshield = front rack
6' behind that = rear rack
3' to back edge of roof

or should I make it 5' between racks?? and split the difference on the 12' roof?

Thanks Zoneoids 

[Dwight (DW)]

Always liked hanging over the hood so I can see my load. Load vibrating, etc.

Never liked anything hanging too far either direction. Risk of load getting clipped in parking lot.

[supthecreek]

Thanks Dwight, that makes sense.

I travel a lot of highway miles with my 14' "surf style" board on my Honda Civic, nose forward and down.
Those racks are only 3 feet apart.... but the air pressure actually pushes the board and rack down toward the roof.
It's solid at 80 mph.

But I don't have any experience with a raceboard..... the aerodynamics seem like they would be a lot different.
and spacing these van "ladder racks" is completely new to me.

[TallDude]

5' to 6' is fine. The strapping can do some damage to a race board. They are a lot of foam with minimal reinforcement. More susceptible to crushing than a surf type sup. A the middle of the board the bottom is flatter so it sits flat and the top rail of the board is usually a stronger turned edge. As you get closer to the nose the board gets much rounder, so it doesn't sit flat against the roof rack. I usually let mine hang off the back and hold it back of the windshield by about a foot on my truck racks.

[supthecreek]

Thanks TD!

How are they at highway speeds, for long hauls.... like 1,500 miles?
I may just put the raceboard inside and put surf SUPs on the roof, but want to weigh all options, as I will possibly be traveling with a lot of boards inside and out.

[TallDude]

I've drive with my race boards on my racks for thousands of miles. Never had a problem. It's the desert heat (115 deg) that worries me, but as long as air flows through the bags they have survived. The more the foam, the more the expanding gas from heating. Race boards will literally pop no matter where they are strapped down
I've never worried about heat or had a problem with any of my sup surfboards. On some trips surfing in Baja, I've ended up with a puddle of wax on top of my car.

[supthecreek]

Thanks for all the info guys!

This set of racks must be 20 years old, cuz there was not ONE reference of any kind, found in my million Google searches.
No video, no pictures, not one mention of them on the Weatherguard rack site.

Odd boogers to set the towers properly in the gutters, kinda like a Chinese finger puzzle.... every time one bolt was set, another one went out of position, but I got 'er done.

Every part of them is aluminum or stainless steel..... freeking beasts, in perfect shape.
After I installed them a friend gave me a pair of beefy 48" surfboard rack sleeves to go on the bars. Perfect fit 

Chose 5 feet between bars, to tie raceboard at strongest point (standing area)
A tad forward of center so I can strap down from the side doors.

The board on the rack is 12' long, just even with the back of the roof.... and 1 foot in front of it.

I'll tie 12'er down with nose at the windshield edge, so the raceboard will extend to 1 foot over windshield.

At some point I will take the sliding tie downs, off the bars... but not until I take the racks off in Florida (the cushioned rack sleeves make tie downs useless)

I already have 10 boards inside.... and I am picking more up on the way south