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Discussion Starter · #1 ·
Hi Guys, finally got to the track today. Fontana Street Legal Drags. I wanted to get some times on my Truck BEFORE I did anything to it. 633 Miles on the Odometer. Completely Stock. Pretty cool rainy day. The truck cooled off and never did warm up properly even though I idled it for a while before each pass. Not sure how that will affect performance. Anyhow, best of 15.29 leaving at 1000 RPM. Very slight PowerBrake. I do think that is all the tires will hold as it was spinning ever so slightly. Best MPH of 88.49 As a side note, I had the tailgate down for the second run and the 1/8 mile speed was higher due to the powerbrake start , BUT the 1/4 mile speed was down. I have heard that lowering the tailgait can actually HURT aerodynamics, not help. This seems to support that. Could be a coincidence. Only got 2 passes and it started to rain :mad: Overall, I am VERY happy with the performance and now the FUN will begin. Should dip into the high 14's with the M&H's and a Boosted Launch):h BTW it's 2WD.
 

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Those are some really good stock times, mph is really good. Is your truck a 2wd, or were you just running in 2wd?
 

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Pretty good times. That is faster and quicker than my wife's stock 05 V6 Mustang which got high 15's.
 

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Discussion Starter · #4 ·
?wd

My Truck is a 2 BY. I think it is odd how high up, it sits. But, I kinda like it since it LOOKS like a 4 W D. It's actually slightly difficult to get into. Yeah, I am real happy with that MPH. Should be a little faster once it breaks in. We'll see. I should have quite a few passes on it by the time Edge comes out with a programmer.
 

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"I had the tailgate down for the second run and... the 1/4 mile speed was down. I have heard that lowering the tailgate can actually HURT aerodynamics, not help."
Aerodynamic drag increases by nearly 4% with no tailgate, while a bed cover reduces drag by over 22%, according to these UofM wind tunnel tests:
http://sitemaker.umich.edu/um.gm.truck

The purpose of this study was to measure the change in the drag by altering the base model in some way. The base model, used in previous tests, was tested to have aerodynamic coefficients of:

CD: 0.311 +/- 0.0006 CL: -0.280 +/- 0.0010

Compared to the base model, the four configurations tested affected the drag as follows:

Sloped Cab Extension: + 5.66 %
Tailgate Off: + 3.92 %
Spoiler: - 6.98 %
Bed Cover: - 22.03 %

Another way to reduce drag is to use a tailcone. But since a tailcone isn't practical in most automotive applications, the next best thing is to create a "virtual tailcone" using vortex generators, like these:
http://www.airtab.com/
 

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so then maybe then a stock 4wd would be able to dip into the high 14 second club, WOW

now would the latest cummins be ablw to match that?
 

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Can anybody explain how the tailgate down creates more drag? It sure sounds counter intuitive!
 

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"Can anybody explain how the tailgate down creates more drag? It sure sounds counter intuitive!"
Well, for starters, aerodynamics often isn't "intuitive."

But if you read the article at the link provided, it explains how the tailgate down (or removed) provides a large blunt area (the back of the cab) as a trailing edge. The flat bed cover provides a big improvement by providing what amounts to a 'step' of sorts.

Actually, an even better bed cover (or cap) would be one that wasn't flat. Instead it would be rounded and sloped, more like a "boat-tail." Imagine a cap sort of like this one, but taken even farther compared to a typical cap, i.e.: even more sloped & rounded on the both the back and the sides: http://www.snugtop.com/p_topgun.htm
 

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so then maybe then a stock 4wd would be able to dip into the high 14 second club, WOW

now would the latest cummins be ablw to match that?
Me and my brother in law test drove both the LBZ and a new dodge back to back. Totally different, LBZ felt like it would run high 15s and the Dodge felt like it would run high 16s to low 17s. He traded his Dodge in on an LBZ.
 

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Thats awesome!!! Great times! There was some guy on here who was saying his stock Stroker smoked "his brothers stock LBZ". Yeah right...since when will a stock PowerJoke run 15.2??? :)

--Ben
 

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Great times for a stock truck.

Now you need to stack the bully dog with the duramaximizer, add NOS, maybe a bit of propane, get your alli built and you will be seeing low 12's :D
 

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Discussion Starter · #12 ·
More thoughts!!

Elvis knows, if you study those time slips they absolutely support that theory. I believe it!! I wish I could have made more runs as the tailgate was going back up!! Plus I was going to fold in those BIG AZZ MIRRORS. They are out there like big sails :)

DuraToTheMAX. I don't think so......My good friend has a 06 Ford Powerstroke CCSB 4WD and I have been to the track with him, "So I know what it runs". He ran 65 MPH in the 1/8 compared to my Cummins at 69 and this Chevy LBZ at 72. Now he may have got a "bad one" and I believe the Cummins could be a "good one" (it was a sold Employee purchase, and the guys on the assembly line know that). My LBZ is what I would consider average to good. I am happy. He could only beat me in the 1/8 with my Cummins by virtue of a boosted 4WD Launch. My best Guess of "His" Quarter mile Time based on what my Cummins would run would be a 16.0 - 16.1 @ 80 - 81 MPH and thats being generous):h

MaxPower.....WOAH! I am only planning on an intake, exaust, edge and traction. I want to run 13.50 and keep my trans stock. Plus, I will probably run the edge on level 1 when I bracket race. Depends on what I feel (my confidence), and what I read on here.
 

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yeah thats what I was saying..stock for stock an LBZ is much quicker than a 6.0h no
 

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question, was that with the tow/haul on or off? sorta curious. great times):h
 

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Discussion Starter · #15 ·
Tow/Haul

Hi, Good question!! The tow/haul was off. First pass was leaving from a dead idle/mashing the gas all the way and second pass was powerbraking to 1000 RPM. Don't know how much boost that will develop, but it certainly helped. Both passes transmission was in automatic. I wish it had not rained because I wanted to try the tow/haul. Owners manual says the converter will lock in second gear with it on. That may help ET's.
 

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Discussion Starter · #17 ·
Stock Trannie!!

FredW, I am going to try. My M&H's are a little shorter than the stock tires and when I run the Edge I will enable the defueling during shifts feature if there is one. What will kill a stock trans it those BIG AZZ Tires you have on your Truck!! They Kick AZZ on looks (and the trans) :) Plus my Truck is lighter which I would think would help. My plan is to try and make it on the stock trans, and if it blows up, then I will build it. It's my second vehicle, so I will not dump a bunch of money into the Trans unless I need to.:(
 

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yep tailgate up you get better MPG and a faster truck they did it on mythbusters awhile back
 

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I turned a best of 13.92 with my stock trans and juice/att(120) with a extended cab 4wd so it is possible. That was with a 4wd boosted launch though.
 

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wow, if you can get to 13.5 on a stock tranny, power to ya
I believe it's possible, I did 13.9x's consistantly on a stock trans with my LB7........
 
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