Gas Guzzler

G

Ghostrider

Charter Member 2012
I'm trying to work up an air file for the B-29 that will give it a realistic range without using the unlimited fuel option. I have multiplied the fuel capacities of the three tanks by 8, and correspondingly reduced the fuel weight so I could still take off, but it seems that no matter what I do, I can only get about 2-1/2 hours of flight time at 30,000 feet. This is about halfway from Tinian to Japan. Then I'm outta gas. I'm using the Aired program, but it seems that quadrupling fuel helps, but 8x doesn't get me any further. Is there a way to reduce fuel consumption somehow? I don't use automixture either, so am running a pretty rare mix at 30,000 feet.

Anyone got any ideas? Thanks,:ernae:
 
Cheat on the weights and drags

You can try.......

1. change the weight of bomb, rockets, and bullets in the damage profile..........

2. reduce drag coefficent.......(non lift drag.......ect.....) in the xxx.air file...........
 
I think the big Wright 3350s on the B-29s had auto fuel mixture control. Are you using manual mixture control or auto in the flights. You might try it with the opposite of your current settings. If on manual, are you leaning the mixture out enough for max economy as well as reducing the prop RPM? When leaned out, watch your cylinder head tempuratures closely.
 
Hmmm Have tried with both auto and manual mix with about the same results. Need to check my prop RPMs... Thanks again!
 
Switched my second axis from mixture to prop RPMs, and enabled automix. Got about 3-1/2 hours flight time instead of 2-1/2, but still got just past the Bonins... Next will try reducing drag in .air file... Still a long way to Tokyo :japan: not to mention the return trip!
 
Hi Ghostrider,

Are you using warp? The B24 has the same problem when using warp.
Reducing drag will help, but you will get to a point where the aircraft will not fly right.
I have come to the fact that sometimes one will just have to use unlimited fuel.

Regards,
B24Guy
 
DreamWheeling....

Haven't tried this yet myself....

But what would happen if you tweaked the initial overall weight of the B-29 lower ? How about reducing the fuel weight per gallon ? All done in the AIR file, of course...

Seems that it would extend the flight time if the combined weights were much lower... of course, that flies in the face of reality... but might gain the desired result.

Jus' Sayin'
SC
:kilroy:
 
The Flight Engineer manually controlled mixture, among other things, from his station, example here --> http://home.att.net/~sallyann4/rtw1.html




If you set up an additional 4-engine ECU panel in your panel.cfg, you can manually control your mixture and lean it out nicely at that altitude for max range. And turn off automixture. At angels 30 you should be optimizing fuel consumption if you lean it to near cutoff position.
 
I think I'm doing all of these things - got her leaned out to almost cutoff mix at altitude, RPMs way back, airspeed and fuel consumption optimized (got a great engineer panel) I've cut my fuel weight from 6 to .05lbs./gallon or something ridiculously low like that. Carrying eight times the fuel in the original .air file. Haven't changed aircraft weight or drag yet - worried about messing up her flight characteristics. Not warping, just trimming for straight and level at angels 30 and accelerating time to about 32X. It's about a ten-hour round trip, and the best I've done yet is about 3-1/2 hours in the air before running out of fuel. I am carrying a full load of ordnance, I kind of figure if I can't do that, what's the point? : )

Anyone know how to add fuel tanks to the air file? Or to reduce fuel consumption of the engines? I'm stumped... Thanks for all of the advice! Worst comes to worst, yeah, I'll just use unlimited fuel.
 
Max range is listed at about 3200 Miles with a 5000lb bomb load. Round trip from Tinian to Japan is roughly 3000 miles, so I'm sure these guys were sweating their fuel management! My .air file is only getting me about 900 miles max range.

edit: I stand corrected - Tinian to Tokyo was 1600 miles. Max range is listed by one source as 3250 miles. They must have been on vapor when they landed!
 
Update: the DPs I had had me hauling a lot more bombs than I should have been at 30,000 feet. The bombload at max range at that altitude was 5000lbs. I have made two more payloads to reflect this as well as a 12,000lb bomb load at max range and medium altitude. Still in the process of activating Air Wrench, which looks to be much more capable than Air ed. Thanks SC7500!
 
Just some thoughts

Through talking with Rami during his many campaign rebuilds; I've noticed that he has found many of the AIR files do not accurately depict real-world engine performance. (and therefore all aspects of it including fuel consumption)

In many instances I have been honestly shocked at how far some of these AIR files are "out of whack". In many of them; the term: "complete fantasy" would be an accurate description.

Rami is a real stickler for detail .... he researches the particular engine and then adjusts the AIR to model those specs as closely as possible. Guys; he takes this right down to the nitty-gritty-picky details like: bore-stroke, compression ratio and supercharger boost pressure ... and I'd almost swear he gets grease under his fingernails at times!!!

The end result is that not only do most aspects of the planes "flight envelope" fall right into place; but the fuel consumption is usually right bang-on spec.


It would appear that you've covered all the bases except perhaps this? .... maybe this is the root cause of your trouble?

Remember too that the specified range is only an estimate. In the real world it will be greatly effected by many variable factors such as: altitude, wind direction & speed, ambient temperature, barometric pressure, engine condition and fuel quality/octane to name a few.
.
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Yes, Dirtman, I believe that is the heart of the problem - somehow my virtual Wright Cyclones are sucking up way more fuel than they're supposed to. I have faith that if I get the numbers right, things will work as they should. SC7500 has directed me to a much more capable .air file tweaker than I have been using, and I have high hopes that I can get it done with the new prog. It will even estimate range given certain parameters such as altitutde, speed, payload, etc. so I should be able to see if I'm getting closer without having to go fly these long, long missions every time to see where I run out of gas. You've all given me some great ideas, and I'm having a good time, learning more about CFS2 (still after 10 years), learning more about flying, the B-29, and what the aviation pioneers who flew them so far, so high, and so fast in 1944-45 did. So it's all good!
 
Another VERY interesting thread.
And I loved this: "and I'd almost swear he gets grease under his fingernails at times!!!"
 
Dirtman said:
... I have been honestly shocked at how far some of these AIR files are "out of whack". In many of them; the term: "complete fantasy" would be an accurate description....
Click to expand...

:icon_lol:...Damn !!!... Silly me...NOW he tells me....for all these years i was thinkin' the entire simulator was just a fantasy, let alone the air files. OK, i'm gonna need a major paradigm shift here as i toss out the fun factors. :icon_lol:
 
Well i dunno pilgrim...the name's 'bearcat', not 'easykill' ;)...Rami's about the only regular here who's flown with me online...he never got me 1v1, but that was a long time ago and i'm sure his reality skills are much better by now. :salute:
 
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