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Chevy S-10 Mods

Bed Cover Increases Gas Mileage- - driving with tailgate down deceases mileage! 

 CLICK to See Why


Construct Sub Woofer Box.  CLICK

Check Out Inexpensive S-10 V6 Exhaust and Intake Modifications


MIG Gas Delivery and the Small Block Chevy Evolved in a Similar Way and Time!

 Both had Advances and Setbacks Before

They Were Optimized!


Click for a PDF Report on the Similarities


Air Drag - - Why a Bed Cover is the Way To Go!

bed_cover_copy.jpgAn interesting study at the University of Michigan ( photo on left was posted on their web site which is no longer active) showed that a full hard bed cover decreased drag by 22%.  This seems intuitively reasonable.  A key benefit is the reduced drag at the back of the Cab since there is less of it exposed.

They also found that eliminating the tailgate increased drag by 4%!  Why?  What occurs with the tailgate up is an air bubble forms in the bed which causes air to move over the bed and reduces the low pressure area behind the cab.  When you drop the tailgate you eliminate the bubble and your back to a greater low pressure area behind the cab!  Air flow is not always intuitive. 

If your convinced you get better mileage with the tailgate down don't blame me for the University of Michigan providing facts!  Aerodynamics are tricky, that's why NASCAR teams spend lots of time and big bucks in wind tunnels!   I suspect some trucks might be slightly different but it would not come close to what a bed cover will provide.

Here Are Comments Copied from Click and Clack, the "Tappet Brothers" Web Site (for what its worth):

"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"

Some Additional Data For The Skeptics (found on a web site):

"...it is generally better to keep your pickup truck tailgate up instead of down or removed. It seems counter intuitive, but research by the National Research Council of Canada determined that there was generally a lower drag coefficient (Cd) with the tailgate up than with the tailgate down or removed. The difference wasn't big but it was measurable, with a 2002 Ford F150 Crew Cab measuring a Cd of 0.5304 with the tailgate up and 0.5425 with tailgate down. With the tailgate removed, the Cd was 0.5596. However, placing a tonneau cover on the bed lowered the Cd to 0.4967, probably enough to offset the weight of the tonneau cover if you do much highway driving."  [Note (0.5425-0.5304)/0.5304 = 2.3% more drag with a lowered tail gate and (0.5596-.5304)/0.5304 = 5.5% more drag with it removed!]

You Have to Believe "MYTHBUSTERS!"

Adam and Jamie, hosts of  the TV show MYTHBUSTERS, drove two identical  Ford F150 pickup trucks filled with identical amounts of gas.  One with the tailgate up the other down.  They drove the same road and after 500 miles the one with the tailgate up went 30 miles further before it ran out of gas!  That's 6% better (30/500!)

Spotlight Example of Air Flow

Many years ago in a fluid dynamics class it was mentioned there is more drag with a bullet shaped spotlight on a car pointing with the bullet shape toward the front than with the flat face moving forward (Back in the "Old Days" some "Custom Car Guys" mounted spotlights on each A pillar, bullet end forward!)   Why we asked?  Similar reasoning as with the truck tailgate.  With the bullet shape pointing forward there is somewhat less drag in the front but a large low pressure area in the rear.  In essence a slight partial vacuum is created pulling the spotlight backward.  You can visualize the massive turbulence and vortexes created as the spotlight moves through the air.  With the bullet shape pointed backward the air moves smoothly to the rear.  Even the front drag increase is not as great as it might seem since the air will partially create its own path over the front.  The net result is there is the reduced rear drag more than offsets the increased front drag with the bullet shaped spotlight having the glass front facing forward! 

In the early days of streamlining race cars very long tails were being used.  Then someone found a spoiler helped create a similar effect and also produced some down force...but that's another story! 

Final Thoughts: As a cost reduction, for the 2009 Formula 1 Racing Series the rules are limiting teams to use no more than one wind tunnel and state that devices can only be used for 15 runs per eight-hour day and only five days per week.  The lead teams have their own wind tunnels and reportedly would spend three shifts looking for the small advantage it takes to win.   How much does a wind tunnel cost? Clemson University announced they plan to build one for NASCAR vehicles at a cost of $40 million!   What does a top Formula 1 team cost to run?  Honda quit F1  for 2009 saying with the  economic downturn it needs to focus on its core business of making and selling cars rather than spending $291 million a year to race them on Grand Prix tracks!  Ferrari and McLaren probably spent more than that in 2008 when the Championship got very light at the end!

So when you think your "common sense" says you'll get better mileage with the tailgate down think about the many millions race car teams spend in a wind tunnel since they know even  their '"educated intuition" is usually wrong when it comes to air flow!  Maybe you need to get your truck in a wind tunnel!

By the way; according to a Ford Aero Systems Engineer, flow-through, web-like fabric tailgates tend to increase drag even more than just leaving the tailgate down!  They have measured as much as 4- to 5-percent more!

Sub Woofer Box Construction


Birch Plywood, 3/4 inch thick, was glued and screwed to fit behind the console and house the sub woofer.  It was sized to provide the correct volume as recommended by the speaker manufacturer.  Upper left photo is the raw box before cutting the sub woofer opening, adding acoustic stuffing and covering with "interior matching" black Naugahyde (sorry PETA folks, but they tell me its done humanly!!). The 600 Watt Power Amp (visible in the photo upper right) mounts to the rear cab wall.  It has a remote base adjustment that is mounted to the passenger side of the console.  To mount the woofer and amp Stainless # 10 Bolts and Fender Washers were inserted from the rear (Used small ID tubing and pulled them  through from the rear. Also put silicon on the fender washer to seal the drilled hole and bolt.  Looks much better than the sheet metal screws used in the '94!


This Ad Helps Bring You  Free Information on S-10 Mods

Have a Welder?   Improve Weld Starts and Have Shielding Gas Cylinder Last at Least Twice as Long! 

Note: Our Patented GSS is Not Available in "Stores"

A home shop fabricator in Georgia with a Miller TM 175 amp welder purchased a 50 foot Gas Saver System ( GSSTM ) so he could use a larger cylinder and mount it on the wall of his shop.  He wrote:

"The system works great.  Thanks for the professional service and a great product."   Click To See His Home Shop


A Professional Street Rod Builder Had This to Say:

With their standard MIG welder gas delivery hose the peak shielding flow at weld start was measured at 150 CFH. That caused air to be sucked into the gas stream causing poor weld starts.  With the GSS replacing their existing hose, the peak flow surge at the weld start was about 50 CFH.  Total gas use was cut in half.

Kyle Bond, President, quickly saw the improvement achieved in weld start quality as a significant advantage!   Kyle, an excellent automotive painter, was well aware of the effects of gas surge caused by pressure buildup in the delivery hose when stopped.  He has to deal with the visible effects in the air hose lines on the spray gun in his paint booth!  The paint surge is visible and creates defects unless the gun is triggered off the part being painted!  We can’t do that with our MIG gun!


Engineering a 1934 Pro Street Street Rod



Click for a 67 Page PDF


Click for YouTube Video Overview of Car


See Details of Our 1934 Ford ProStreet Street Rod

This Site:

We're "hitchhiking" on our commercial web site to bring you this information on 1934 Street Rod   If you or a friend have a MIG Welder (also called a Wire Welder, GMAW, etc) visit our site on How To Save Shielding Gas Waste. You can reduce the number of times and the effort required to have your shielding gas cylinder filled in half!  Just click on the  This Link.  You can return to this site by using the  Links at the bottom of the "CAR BUFFS" page.

$ave money and get better weld starts!

If you make a lot of short welds and weld tacks you can probably reduce your gas usage by 50% or more.  Also fewer trips to have the cylinder filled. 

See these other pages for more details:



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