I'm heading to the drags this weekend for the first time and I was wondering...Should I have the tailgate up, down or off for my 1/4 mile runs? I've read differing opinions on this and would like to hear from some of you more experienced folks. Logic says "put it down" but I also read here somewhere that the tailgate doesn't affect wind resistance on a Lightning.

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Red '00 Lightning

 

I would stick with logic. Put the tailgate down, unless you have some kind of cover over the bed.

 

Redshift: I have a cover on my bed, however, I take my tailgate off at the track for 2 reasons. One being, I can save weight. The second being one you might regret. I ran with my tailgate down once, and the rubber, pebbles, and other foreign debris absolutely plastered my tailgate. I left with some really stuck on rubber, and a few nice scratches.

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1995 F-150 Regular Cab Flareside w/ 302 V8... Mods: Mass Air, K&N FIPK, Dual Exhaust (no mufflers), Lund Premier Tonneau Cover, Motorsports 9mm Plug Wires, full JL/Kicker/Pioneer system, Autometer 5" tach, Superchip, Precision Gear 3.73s

Best 1/8th ET: 10.6837 @ 64.9561 MPH

The F-150 Resource Guide

The F-150 Resource Guide-- a site dedicated to 1987 through 1996 F-series trucks.

 

I can run without the gate at my track but they won't let me run with it down...
CA

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Christy Ann
99WhiteLightningSVTGirl
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recent smoke plume tests show the aerodynamics of modern pickup trucks are ruined by tailgate down or off w/o a cover. do not know if the weight savings on the strip offset lost aerodynamics or not.

 

I have done this many times to test.My times have not changed at all one way or the other.Leave it up and what it does, it does.I know when I see a tailgate down at a track,I think of the person trying to squeeze every last ET out of it

 

My cousin and I took our Lightnings (both 99's) to the track a couple months ago and ran. I have the factory bed cover, he has no cover. Mine was always quicker than his, and could always walk on him on top end. Mine was a consistent 2 tenths quicker than his. We decided to try his with the tailgate down and instantly picked up about 0.15 of a second. It did make a difference on his truck. Mine (red)is still quicker than his though(black)!!

 

My experiences with my '95 are the same as Lightningquick, but I haven't tried any different configurations with the '00. Up or down, on or off, it made absolutely no difference.

I know that in mileage testing by a truck magazine, they found that mileage decreased with the tailgate down because of the way air wrapped under the tailgate and created drag. I'd think the same would apply on the drag strip.

Bottom line - do your own testing. I wouldn't expect a difference one way or the other though - on runs with practically identical 60' times, that is. You have to eliminate the launch factor.



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Later!
Jeff S.
http://nloc.org
SVT Lightning #74 in '95 - 11.92@115.2 on radials, driven daily
SVT Lightning #?? in '00 - 13.68@99.5 STOCK (except for the Jack In The Box antenna ball power option)
fmosracing@aol.com

 

This guy corrected Bob & Tom the car experts, who advised getting one of those cloth airgates to let the air pass thru the tailgate.

I'm an aerodynamics engineer. When I was in the U.S. Air Force a few years back, I worked with folks from the Lockheed low-speed wind tunnel. In the 1970s, aircraft production went into a slump, and Lockheed started looking for other customers for its wind-tunnel services. Prime candidates were the auto makers, and Lockheed was successful in convincing Ford, among others, that the wind tunnel would help them reduce drag and wind noise on their vehicles. Needless to say, in the past 15-20 years, Lockheed has learned a lot about car and truck aerodynamics. Anyway, they actually performed drag tests on pickups with the tailgate both up and down, and found that drag was actually LOWER with the tailgate CLOSED! This ran counter to their intuition (and yours). The reason is that a closed tailgate sets up a large "bubble" of stagnant air that slowly circulates around the bed of the truck (we aero types call this a "separated bubble"). When air approaches the truck, it "sees" the bubble as part of the truck. So to the air, the truck looks like it has a nice, flat covering over the bed, and the air doesn't "slam" into the vertical tailgate. If the tailgate is open, or replaced by one of those "air gate" nets, however, that nice, separate bubble in the truck bed does not form (it "bursts"). Then the air approaching the truck "sees" a truck with a flat bed on the back of a tall cab. This is a very nonaerodynamic shape with a very LARGE drag. So, believe it or not, it's best for gas mileage to keep the tailgate CLOSED. Hope this information is helpful. Ed Fitzgerald, Research Assistant, Dept. of Aero/Mechanical Engineering, U. of Notre Dame

 

I've posted this before, but the Baha boys who run hard and fast and have lots of money wind tunnel tested their trucks with the tailgate up and down and found it didn't make any better speed with the tailgate down. It's physicaological, like turning off the overdrive at an 1/8 mile strip. If it makes you feel faster, do it!!!
noelvm

 

Believe it or not, I could never break 99mph in the 1/4 until I put my tailgate down. This is a fact! One night I made three runs at 99mph and then lowered my tailgate just as a joke really and then it appeared, the big 100. It really helped toward the end of the 1/4. I was racing 99SVT at the time and he had been pulling on me a little at the end every time that night. That is until I lowered the tailgate. I kept stedy pulling from him the whole way then. I am convinced the tailgate was the reason, I realize most will probable disagree but, oh well.

 

Believe it or not, I could never break 99mph in the 1/4 until I put my tailgate down. This is a fact! One night I made three runs at 99mph and then lowered my tailgate just as a joke really and then it appeared, the big 100. It really helped toward the end of the 1/4. I was racing 99SVT at the time and he had been pulling on me a little at the end every time that night. That is until I lowered the tailgate. I kept stedy pulling from him the whole way then. I am convinced the tailgate was the reason, I realize most will probable disagree but, oh well.

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99-White
6-9-99
#2163
13.55@100.89
Airaid
PSP chip
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ttb.org !!

 

It looks like I need to try it both ways but I am leaning toward "closed". Thanks a million. I love this board!

 

And if you are still not sure, stay at the holiday inn, atleast you'll feel faster, or is that smarter? ohwell.


Uh, nevermind.

 

I've always failed to see the point of this at even the 1/4 mile strip. They don't shift into O/D until what? 115 MPH? There's only one L that even approaches that speed that I'm aware of.

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Red '00 Lightning,
Adopted 4/19/00,
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