dyno jet?

Another question... what amount of boost would one expect with an ETC pump, Comp, and Mach6s with a non-wastegated 64 at sea level? How about 6000'?
 
In the John Maden voice..........

Well ya see, ya got a lot of power down at level and then ya got a lot of power at 6k but ya don't have as much power at 6k as ya do at level.

LOL
 
Dockboy said:
Michael,

There is no "setup" on a Dynojet ;) As long as the rpm is reading right, the hp/tq is what it is. The only thing that can effect that is what the weather station determines the CF to be. Otherwise, the uncorrected numbers can not be effected by any "setup", only by operation.


David, I need to do some tuning on your dyno sometime!!! :) My Dynojet numbers are consistantly 100 hp lower than my trap speed calculations!!!:doh:
Click to expand...

I bet if you punched in the "correct" weight of your truck when you made those runs your dyno numbers would be right on the money.:doh:
 
Just thinking about some things. Decided to bring out the old calculator, and weather station and do some research.

Denver vs Atlanta comparison for today.

Denver Atlanta

Temp - 91 93
Hum - 8% 34%
Baro - 29.68 29.99
Dew - 23 deg 61 deg

At 5000 feet Denver's Absolute pressure becomes 24.69 and would show a correction factor if 1.24

At 1200 feet Atlanta's Absolute Pressure becomes 28.72 and would show a correction factor if 1.06

Apply 40 pounds of boost to those numbers and Denver correction goes to 1.07 and Atlanta goes to 1.04

Adjustment for boost was calculated using this formula.

CF= 1.18 * {(29.235+gp_in_hg)/[Bdo+gp_in_hg-((gp_in_hg/abspress)*vapress)]} * ((Square Root(To+273)/298)) – 0.18)

To = Intake air temperature in Centigrade
Bdo = Dry ambient absolute barometric pressure in inches of mercury
gp_in_hg = gauge boost in inches of mercury
abspress = absolute atmospheric pressure in inches of mercury
vapress = vapor pressure in inches of mercury

That should get some discussion started. LOL
 
I KNOW there has got to be somebody out there to try to refute David's arguement.....
 
Not familar with that formula but that suggests that the CF is only valid at a specific gauge boost. I don't make 40psi boost up here. Closer to 33. On the other hand a twin turbo setup might make 65 up here. I guess we should ask for a max boost defined CF setup next time. That also suggests that numbers at anything other than max boost will be skewed... Didn't take the time to figure out the magnitude of change that gauge boost has upon that calculation.
 
you could tell me that that formula says you gain HP if you fart at 3200 RPM and I'd believe you LOL
 
Timbeaux38 said:
you could tell me that that formula says you gain HP if you fart at 3200 RPM and I'd believe you LOL
Click to expand...


On this fart:
Yes but at a higher altitude your pyrometer will be peaked compared to a dense air situation, where your peak egt readings will be different, and you can carry that fart longer without causing damage......LOL LOL
 
Fart power aside I wonder how much I gave up on my 580 run because of dyno'ing in direct drive instead of OD and my 35" tires... hmmm
 
wow good thread guys, enjoyed the "banter" and now im trying to keep up with all the great info in the reading :)
 
duke1n said:
Fart power aside I wonder how much I gave up on my 580 run because of dyno'ing in direct drive instead of OD and my 35" tires... hmmm
Click to expand...
I think David will tell you that the HP would have been close, but tour TQ #'s would have been down a bit. I dunno about the 35's though, I would assume a smaller tire would decrease the amount of rotational mass and unleash some extra HP.
 
According to David my Rickson's are good for stealing about 7-10HP, they are a 34" tire that wieghs 150lbs for the tire and rim. That is mass that has to be spun and that takes power that is not gonna show on the rollers.
 
....er, are we talking about rotational mass or fulcrum resistance via~ larger diameter? I've seen better numbers out of 285's than 245's on Duramaxes....donno why?
 
Fsnow said:
I bet if you punched in the "correct" weight of your truck when you made those runs your dyno numbers would be right on the money.:doh:
Click to expand...

Just saw this:doh:

Hey Mr. Wizard......You don't "punch in" a weight on a Dynojet!:bang :poke:
 
DavidTD said:
Apply 40 pounds of boost to those numbers and Denver correction goes to 1.07 and Atlanta goes to 1.04

That should get some discussion started. LOL
Click to expand...

Our correction factor hovers around 1.06-1.10. I have it setup for 30 psi of boost. So you are spot on with your calculation.

Tadd
 
Burner said:
....er, are we talking about rotational mass or fulcrum resistance via~ larger diameter? I've seen better numbers out of 285's than 245's on Duramaxes....donno why?
Click to expand...

It will be change in Angular momentum. It deals with moment of inertia. I think a taller tire could do better because it can load the engine and build boost that would be negated by the moment of inertia of the tire but HP could be higher

Billy has what is commonly refered to in the industry as Sissy Ninny baby tires. they do steal 10 HP out right as they are full of CHIT!!!:shake:
 
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