Just a trick for you all to try with tailgates... With an empty beverage
can of your choice, reach out your window and place it bottom down on top
the roof of your truck going down the highway.
Make one last check for the fuzz and release the can... It'll hit the tip
of the tailgate every time and bounce out and onto the highway.
This highly scientific study in aerodynamics might lead you to believe that
your claim about Lockheed's testing might be true.
----- Original Message -----
From: "Barret, Matt" <MATT_BARRET@earthtech.com>
To: <dakota-truck@buffnet.net>
Sent: Tuesday, July 11, 2000 2:21 PM
Subject: DML: RE: attn.Steven. tailgate up or down
> No, .25 to .50 seconds in the quarter mile is alot of time. Would normally
> take 20 to 50 HP for those gains, or 200 to 500 lbs of weight reduction. I
> really don't believe in the theory of drag from a tailgate at highway
speeds
> 90 mph or less. The design engineers take that into consideration when
> designing the aerodynamics of the truck. They engineer the roof lines to
> deflect most air up over the tailgate. I won't say there is no air drag
> from a tailgate, but I believe the significance of it is a non factor
under
> normal speeds.
> Now, in older trucks, like anything older than say 1990, they probably
> didn't do any aero work on the design, so the tailgate down theory may
apply
> to these designs. But by todays standards they are tweaking fuel economy
as
> much as possible.
> I have raced with the tailgate on and off, and observed no difference in
> ET's.
>
> The subject of the tailgate up or down and its effects on fuel mileage and
> drag has always been a hot topic . Most people are either in one side of
the
> fence or the other. I have had 3 trucks, 84 Ram, 85 F-150, and now the
Dak.
> I have experimented with the tailgate down/up and have never seen any
> increased MPG with it down.
>
> Lockhead Aircraft did wind tunnel testing on trucks in the 90's with
> tailgate up and down and actually found that leaving the gate up created
> less drag than putting the gate down!! A "separated air bubble" forms in
> the bed of the truck at highway speed which lets the air flow freely over
> the tailgate.
>
> I'm sure this will spark some interesting comments :)
>
>
> matt
>
>
>
> -----Original Message-----
> From: Stlaurent Mr Steven [mailto:STLAURENTS@mctssa.usmc.mil]
> Sent: Tuesday, July 11, 2000 2:17 PM
> To: 'dakota-truck@buffnet.net'
> Subject: DML: RE: RE: RE: RE: Re: RE: attn.Steven. was Richmond D'way
>
>
> I wonder if any air turbulence is occurring while drag racing and if you
can
> gain a .25 to .50 of a second time with a cover over the bed.
>
> -------------------------------------------
> Steven St.Laurent
> Test Engineer
> Test Branch, GSD, MCTSSA
> MARCORSYSCOM, USMC
> 760-725-2506 (DSN 365-2506)
> Work:mailto:stlaurents@mctssa.usmc.mil
> Home:mailto:saint1958@home.com
>
>
> -----Original Message-----
> From: Barret, Matt [mailto:MATT_BARRET@earthtech.com]
> Sent: Tuesday, July 11, 2000 10:29 AM
> To: 'dakota-truck@buffnet.net'
> Subject: DML: RE: RE: RE: Re: RE: attn.Steven. was Richmond D'way
>
> Nope, no Tonno cover on my truck, I even leave the tailgate up when
racing.
>
> matt
>
>
> -----Original Message Follows -----
>
>
> ~From: Stlaurent Mr Steven [mailto:STLAURENTS@mctssa.usmc.mil]
> ~Sent: Tuesday, July 11, 2000 1:05 PM
> ~To: 'dakota-truck@buffnet.net'
> ~Subject: DML: RE: RE: Re: RE: attn.Todd/Tim. was Richmond D'way
>
>
> ~Are you running with the tonner cover on when drag racing?~
>
> -------------------------------------------
> Steven St.Laurent
> Test Engineer
> Test Branch, GSD, MCTSSA
> MARCORSYSCOM, USMC
> 760-725-2506 (DSN 365-2506)
> Work:mailto:stlaurents@mctssa.usmc.mil
> Home:mailto:saint1958@home.com
>
>
> -----Original Message-----
> ~From: Barret, Matt [mailto:MATT_BARRET@earthtech.com]
> ~Sent: Tuesday, July 11, 2000 9:56 AM
> ~To: 'dakota-truck@buffnet.net'
> ~Subject: DML: RE: Re: RE: attn.Todd/Tim. was Richmond D'way
>
> ~Yea Todd that would be alot of fun, maybe we could bet together at VMP,
> ~would be 50 miles closer to ya than Richmond Dragway. Although Richmond
is
> a
> quicker track. Tim and I have been trying to get together somewhere so he
> could borrow my slicks. What times have you been running lately?
> These truck are pigs when it comes to weight, my little RC weights 3670
with
> out me, and 3870 with me. Not much you can do to trim weight off the
truck,
> spare tire weighs 50 pounds and the tailgate about 40. To be honest, I
have
> run just as quick with the tailgate on!
>
> Hey Tim, lets get something together, Todd sounds like he's ready to go in
> the low 13's!! In a 4XXX lbs truck, no less!!! hee heee
>
> Matt
>
>
> -----Original Message-----
> From: Todd Flummer [mailto:mustang@netunlimited.net]
> Sent: Tuesday, July 11, 2000 11:23 AM
> To: dakota-truck@buffnet.net
> Subject: DML: Re: RE: attn.Tim B. and Injectors installed... was
> Richmond D'way
>
>
> You guys let me know when you plan to race again and I'll come up that
way.
> I plan on dropping as much weight as I can and maybe even going with the
big
> 150 shot. I think that would put me low to mid 13's.
>
> Todd
> Mustang@netunlimited.net
> www.netunlimited.net/~mustang/
>
> ----- Original Message -----
> From: Barret, Matt <MATT_BARRET@earthtech.com>
> To: <dakota-truck@buffnet.net>
> Sent: Tuesday, July 11, 2000 9:29 AM
> Subject: DML: RE: attn.Tim B. and Injectors installed... was Richmond
D'way
>
>
> > yea, It will be close to the same, but I bet you'll see about a 2 mph
drop
> > or so in trap speed if the 60' times drop by .2's or more. I've got a
> > spreadsheet of 70+ runs that you can compare all the info and see the
MPH
> > fluctuate. I'm talking about strictly 60'. Your Bro spinning 1st and
2nd
> > was probably more along the lines of 100 feet or more, that will
> definitely
> > kill your ET and MPH!! Traction problems for our trucks is only in the
> 1st
> > 60', generally no problem with traction after 60' unless your on some
real
> > bad radials :).
> >
> > Yea, bring that ride up here to Richmond Tim and we'll put the
> > Hoosier-(daddys) on there and watch your truck stab deep in the 14's :)
> > hee heee I'll keep my radials on and run ya ;-) !!
> >
> > Matt
> >
> >
> > -----Original Message Follows -----
> >
> >
> > From: Tim Berry [mailto:coolva1@home.com]
> > Sent: Tuesday, July 11, 2000 8:48 AM
> > To: dakota-truck@buffnet.net
> > Subject: DML: attn. Matt B. and Injectors installed... was Richmond
> > D'way
> >
> >
> > Matt... I think MPH will stay close to the same...
> >
> > My bro spun 1st and 2nd at the track on his first time, last run, and
> turned
> > a 14.4 @101
> > (normally 13.5 @ 105)
> >
> > btw, I installed a set of 24# injectors yesterday.. It seems to be
> catching
> > on (the puter)....
> > Now... When do I get to slap them slicks on my truck??? =-)
> >
> > I feel the injectors MAY have lost a little torque down low, and gave me
> > some extra HP, but I cant tell... it seems the speed-o-meter rises to 60
> in
> > a blink of the eye.... but... only VMP will tell me that =)
> >
> > Tim Berry
> > Chesapeake, VA
> >
> >
> > > Hey Wayne, once you get that rocket hooked up, say, in the 1.8-1.90
> range,
> > > hee heee, That would almost be 12's!! At any rate, mid 13's in a
truck
> > is
> > > flying!!
> > > That high MPH is a good indication of tire spin, I would bet that when
> you
> > > do hook up your MPH will be right around 100 mph even. Congrats!!
> > >
> > > Matt
> >
>
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:52:36 EDT