Altitude vs air temp affect on power

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Altitude vs air temp affect on power

Postby spencerdiesel » Fri Nov 06, 2015 4:19 pm

I like numbers, maybe too much. Anyone have specs/experience with how much air temp must decrease for X amount of increased altitude to maintain the same power/EGTs? For example, if 80 degrees F @ sea level supports X amount of power, what temp would it have to be @ 5,000 ft to support the same power? Assuming it is a linear function etc....
1992 W250, 5 speed, 4.10, Ext. cab Ext. bed, 12.5k winch, 75 gal. fuel tank

H1C/18

Fuel: THD 6x10 VCO sticks, THD 12 psi piston pump, THD fuel pin, 366 spring, fuel screw 2 turns in, timing to the head/ >1/4”
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Re: Altitude vs air temp affect on power

Postby Remps » Fri Nov 06, 2015 5:42 pm

Check out Garretts Boost adviser, available as an app. You can punch in all different numbers, boost, altitude, pressure drop, intake temp, etc. Pretty cool.
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Re: Altitude vs air temp affect on power

Postby spencerdiesel » Fri Nov 06, 2015 6:05 pm

Great idea :D
1992 W250, 5 speed, 4.10, Ext. cab Ext. bed, 12.5k winch, 75 gal. fuel tank

H1C/18

Fuel: THD 6x10 VCO sticks, THD 12 psi piston pump, THD fuel pin, 366 spring, fuel screw 2 turns in, timing to the head/ >1/4”
Muffler delete

Minimum 60% WMO full time since Sep. 2018
spencerdiesel
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Re: Altitude vs air temp affect on power

Postby cougar » Sat Nov 07, 2015 11:57 am

Density altitude. Go to a pilots shop and pick up a cheap E6B calculator. Should come with instructions, but someone should be able to teach you how to use it.
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Re: Altitude vs air temp affect on power

Postby spencerdiesel » Sat Nov 07, 2015 4:03 pm

Another toy ;)
1992 W250, 5 speed, 4.10, Ext. cab Ext. bed, 12.5k winch, 75 gal. fuel tank

H1C/18

Fuel: THD 6x10 VCO sticks, THD 12 psi piston pump, THD fuel pin, 366 spring, fuel screw 2 turns in, timing to the head/ >1/4”
Muffler delete

Minimum 60% WMO full time since Sep. 2018
spencerdiesel
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Re: Altitude vs air temp affect on power

Postby Remps » Sun Nov 08, 2015 10:05 pm

I had a chance to play with a density altitude meter a couple years ago, at 1000 ft above sea level, minus 30 celsius outside, density was equal to 1000 ft below sea level. :grin:
'90 D250 R/C,727,IC,6x.009's,1/8" bump,fuel psi,straight pipe w/5" stack.
'90 W250 R/C,47rh,K@N,HX35,1/8" bump,2nd gen IC,boost,egt,trans temp.3.07's.
'96 2500 S/C L/B,2wd,NV5600,3.54 L/S,cai,egt,pacbrake,mbrp exhaust,10 plate.
Bring back the Bank of Canada, PRE- 1974.
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Re: Altitude vs air temp affect on power

Postby spencerdiesel » Mon Nov 09, 2015 6:13 pm

So if florida freezes over there will be 500 hp VE's everywhere? :lol:
1992 W250, 5 speed, 4.10, Ext. cab Ext. bed, 12.5k winch, 75 gal. fuel tank

H1C/18

Fuel: THD 6x10 VCO sticks, THD 12 psi piston pump, THD fuel pin, 366 spring, fuel screw 2 turns in, timing to the head/ >1/4”
Muffler delete

Minimum 60% WMO full time since Sep. 2018
spencerdiesel
14mm rotor
 
Posts: 1106
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Re: Altitude vs air temp affect on power

Postby RCCUMMINS89 » Mon Nov 09, 2015 7:04 pm

But wait now...... don't tell that to all of the non believers in correction factors. (I'm not saying that correction factors are always correct).

But I will say it is pretty hard to make a big non corrected number at elevation, in the summer.
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Re: Altitude vs air temp affect on power

Postby spencerdiesel » Mon Nov 09, 2015 7:14 pm

True dat
1992 W250, 5 speed, 4.10, Ext. cab Ext. bed, 12.5k winch, 75 gal. fuel tank

H1C/18

Fuel: THD 6x10 VCO sticks, THD 12 psi piston pump, THD fuel pin, 366 spring, fuel screw 2 turns in, timing to the head/ >1/4”
Muffler delete

Minimum 60% WMO full time since Sep. 2018
spencerdiesel
14mm rotor
 
Posts: 1106
Joined: Tue Oct 27, 2015 4:02 pm
Location: Brevard, NC
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